Additive for nonaqueous electrolyte, nonaqueous electrolyte, and electricity storage device

Abstract

The present invention aims to provide an additive for a non-aqueous electrolyte solution with excellent storage stability capable of forming a stable SEI on the surface of an electrode to improve cell performance such as a cycle performance, a discharge/charge capacity, and internal resistance, when the additive is used for electrical storage devices such as non-aqueous electrolyte solution secondary cells and electric double layer capacitors. The present invention also aims to provide a non-aqueous electrolyte solution containing the additive for a non-aqueous electrolyte solution and to provide an electrical storage device using the non-aqueous electrolyte solution. The present invention is an additive for a non-aqueous electrolyte solution, comprising a compound that has a structure represented by the formula (1-1) or (1-2): ##STR00001##
in which A represents C.sub.mH.sub.(2mn)Z.sub.n, m being an integer of 1 to 6, n being an integer of 0 to 12, and Z representing a substituted or unsubstituted alkyl group, a silyl group, a phosphonic acid ester group, an acyl group, a cyano group, or a nitro group, the compound having a lowest unoccupied molecular orbital energy of 3.0 to 0.4 eV, a standard enthalpy of formation of 220 to 40 kcal/mol, and an enthalpy change with hydrolysis reaction of 5 to 5 kcal/mol.

Claims

1. A non-aqueous electrolyte solution, comprising: a non-aqueous solvent; an electrolyte; and an additive comprising a compound: having a lowest unoccupied molecular orbital energy of 3.0 to 0.4 eV, a standard enthalpy of formation of 220 to 40 kcal/mol, and an enthalpy change with hydrolysis reaction of 5 to 5 kcal/mo, and represented by the formula: ##STR00080## wherein A represents C.sub.mH.sub.(2mn)Z.sub.n, m being an integer of 1 to 6, n being an integer of 0 to 12, and Z representing a substituted or unsubstituted alkyl group, a silyl group, a phosphonic acid ester group, an acyl group, a cyano group, or a nitro group; and R.sup.1 is selected from a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted phenyl group, or R.sup.5X.sup.1 in which R.sup.5 represents a substituted or unsubstituted C1-C6 alkylene group and X.sup.1 represents a substituted or unsubstituted phenyl group or a substituted or unsubstituted phenoxy group, and R.sup.2, R.sup.3, and R.sup.4 each independently are selected from a hydrogen atom, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted phenyl group, or R.sup.5X.sup.1 in which R.sup.5 represents a substituted or unsubstituted C1-C6 alkylene group and X.sup.1 represents a substituted or unsubstituted phenyl group or a substituted or unsubstituted phenoxy group, R.sup.2 and R.sup.3 may form a ring together and represent a substituted or unsubstituted C1-C6 alkylene group, a substituted or unsubstituted phenylene group, a carbonyl group, a sulfinyl group, or a C2-C6 divalent group containing alkylene or fluoroalkylene units joined by an ether linkage to each other, and R.sup.1 and R.sup.4, which form no ring, each represent R.sup.6X.sup.2 in which R.sup.6 represents a substituted or unsubstituted C0-C6 alkylene group and X.sup.2 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted C1-C6 alkyl group, or a substituted or unsubstituted phenyl group, or a combination of R.sup.1 and R.sup.2 and a combination of R.sup.3 and R.sup.4 may form a ring together and represent a C1-C6 alkylene group or a C1-C6 alkylene group optionally having an oxygen atom, a nitrogen atom which may have a substituent, or a sulfur atom, in a carbon chain or at an end of a chain.

2. The non-aqueous electrolyte solution according to claim 1, wherein the compound is a disulfonic acid amide compound represented by the formula (3): ##STR00081## wherein A represents C.sub.mH.sub.(2mn)Z.sub.n, m being an integer of 1 to 6, n being an integer of 0 to 12, Z representing a substituted or unsubstituted C1-C4 alkyl group, a silyl group, an acyl group, a cyano group, or a nitro group; R.sup.7 and R.sup.10 each independently represent a substituted or unsubstituted C0-C6 alkylene group; X.sup.3 and X.sup.4 each independently represent a substituted or unsubstituted phenyl group; and R.sup.8 and R.sup.9 each independently represent a hydrogen atom, a substituted or unsubstituted C1-C6 alkyl group, or R.sup.11X.sup.5 in which R.sup.11 represents a substituted or unsubstituted C1-C6 alkylene group and X.sup.5 represents a substituted or unsubstituted phenyl group or a substituted or unsubstituted phenoxy group.

3. The non-aqueous electrolyte solution according to claim 1, wherein the compound is a cyclic disulfonic acid amide compound represented by the formula (9): ##STR00082## wherein R.sup.12 and R.sup.13 each independently represent a substituted or unsubstituted C0-C6 alkylene group, R.sup.14 represents a substituted or unsubstituted C1-C5 alkylene group, R.sup.15 represents a substituted or unsubstituted C1-C5 alkylene group, a substituted or unsubstituted phenylene group, a carbonyl group, a sulfinyl group, or a C2-C6 divalent group containing alkylene or fluoroalkylene units joined by an ether linkage to each other, and X.sup.6 and X.sup.7 each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted C1-C6 alkyl group, or a substituted or unsubstituted phenyl group.

4. The non-aqueous electrolyte solution according to claim 1, wherein the compound is a phosphorus-containing sulfonic acid amide compound represented by the formula (14): ##STR00083## wherein R.sup.16 and R.sup.17 each independently represent a substituted or unsubstituted C1-C6 alkyl group or a substituted or unsubstituted phenyl group, R.sup.18 and R.sup.19 each independently represent a substituted or unsubstituted C0-C6 alkylene group, and X.sup.9 and X.sup.10 each independently represent a hydrogen atom, a substituted or unsubstituted C1-C6 alkyl group, or a substituted or unsubstituted phenyl group; and R.sup.20 and R.sup.21 each independently represent a hydrogen atom, a substituted or unsubstituted C1-C6 alkyl group, or R.sup.22X.sup.11 in which R.sup.22 represents a substituted or unsubstituted C1-C6 alkylene group and X.sup.11 represents a substituted or unsubstituted phenyl group or a substituted or unsubstituted phenoxy group, or R.sup.20 and R.sup.21 may form a ring together and represent a substituted or unsubstituted C1-C6 alkylene group or a substituted or unsubstituted phenylene group, and Y.sup.1 represents a hydrogen atom, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted phenyl group, or a halogen atom.

5. The non-aqueous electrolyte solution according to claim 1, wherein the compound is a disulfonic acid amide compound represented by the formula (17): ##STR00084## wherein R.sup.25 and R.sup.26 each independently represent a C1-C6 alkylene group or a C1-C6 alkylene group having an oxygen atom, a substituted or unsubstituted nitrogen atom, or a sulfur atom, in a carbon chain or at an end of a chain, A represents C.sub.mH.sub.(2mn)Z.sub.n, m being an integer of 1 to 6, n being an integer of 0 to 12, and Z representing a substituted or unsubstituted C1-C4 alkyl group, a silyl group, a phosphonic acid ester group, an acyl group, a cyano group, or a nitro group.

6. The non-aqueous electrolyte solution according to claim 1, wherein the non-aqueous solvent is an aprotic solvent.

7. The non-aqueous electrolyte solution according to claim 6, wherein the aprotic solvent is at least one selected from the group consisting of cyclic carbonates, chain carbonates, aliphatic carboxylic acid esters, lactones, lactams, cyclic ethers, chain ethers, sulfones, and halogenated derivatives of these.

8. The non-aqueous electrolyte solution according to claim 1, wherein the electrolyte includes a lithium salt.

9. The non-aqueous electrolyte solution according to claim 8, wherein the lithium salt is at least one selected from the group consisting of LiAlCl.sub.4, LiBF.sub.4, LiPF.sub.6, LiClO.sub.4, LiAsF.sub.6, and LiSbF.sub.6.

10. An electrical storage device, comprising: the non-aqueous electrolyte solution according to claim 1; a cathode; and an anode.

11. The electrical storage device according to claim 10, wherein the electrical storage device is a lithium-ion battery.

12. The electrical storage device according to claim 10, wherein the electrical storage device is a lithium ion capacitor.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a cross section schematically showing an example of the non-aqueous electrolyte solution secondary cell according to the electrical storage device of the present invention.

DESCRIPTION OF EMBODIMENTS

(2) The present invention will be described in more detail below based on examples. The present invention is not limited to those examples.

EXAMPLE 1

Preparation of methanedisulfonic acid bis(phenylamide) (compound 1)

(3) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N-phenyl amine (10.2 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(4) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(phenylamide) (5.0 g) (0.015 mol). The yield of the methanedisulfonic acid bis(phenylamide) was 30.4% based on the amount of the methanedisulfonyl chloride.

(5) The resulting methanedisulfonic acid bis(phenylamide) was identified by its properties described below.

(6) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.62 (s, 2H), 7.28-7.45 (m, 10H), 4.28 (s, 2H)

EXAMPLE 2

Preparation of methanedisulfonic acid bis(methyl phenyl amide) (compound 2)

(7) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-methylphenyl amine (11.8 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(8) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(methyl phenyl amide) (11.1 g) (0.031 mol). The yield of the methanedisulfonic acid bis(methyl phenyl amide) was 62.5% based on the amount of the methanedisulfonyl chloride.

(9) The resulting methanedisulfonic acid bis(methyl phenyl amide) was identified by its properties described below.

(10) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.30-7.41 (m, 10H), 4.32 (s, 2H), 3.46 (s, 6H)

EXAMPLE 3

Preparation of methanedisulfonic acid bis(benzyl methyl amide) (compound 3)

(11) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-benzylmethylamine (13.3 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(12) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and the solvent was removed from the organic phase by reduced pressure distillation at 25 C. Subsequently, toluene (40.0 g) was added, followed by dropwise addition of methanol (10.0 g), whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(benzyl methyl amide) (2.5 g) (0.007 mol). The yield of the methanedisulfonic acid bis(benzyl methyl amide) was 13.1% based on the amount of the methanedisulfonyl chloride.

(13) The resulting methanedisulfonic acid bis(benzyl methyl amide) was identified by its properties described below.

(14) .sup.1H-nuclear magnetic resonance spectrum (solvent: CD.sub.3CN) (ppm): 7.33-7.44 (m, 10H), 4.66 (s, 2H), 4.41 (s, 4H), 2.82 (s, 6H)

EXAMPLE 4

Preparation of methanedisulfonic acid bis(dibenzylamide (compound 4)

(15) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-dibenzylamine (21.7 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 50 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 50 minutes, followed by stirring over night at the same temperature.

(16) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and the solvent was removed from the organic phase by reduced pressure distillation at 25 C. Subsequently, methanol (35.0 g) was added, whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(dibenzylamide) (10.2 g) (0.019 mol). The yield of the methanedisulfonic acid bis(dibenzylamide) was 38.2% based on the amount of the methanedisulfonyl chloride.

(17) The resulting methanedisulfonic acid bis(dibenzylamide) was identified by its properties described below.

(18) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.27-7.33 (m, 20H), 4.40 (s, 8H), 4.15 (s, 2H)

EXAMPLE 5

Preparation of methanedisulfonic acid bis(4-fluoro phenyl amide) (compound 5)

(19) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N-(4-fluorophenyl)amine (12.2 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 11 hours, followed by stirring over night at the same temperature.

(20) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(4-fluoro phenyl amide) (9.6 g) (0.027 mol). The yield of the methanedisulfonic acid bis(4-fluoro phenyl amide) was 53.0% based on the amount of the methanedisulfonyl chloride.

(21) The resulting methanedisulfonic acid bis(4-fluoro phenyl amide) was identified by its properties described below.

(22) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.34-7.39 (m, 4H), 7.26 (s, 2H), 7.08-7.14 (m, 4H), 4.21 (s, 2H)

EXAMPLE 6

Preparation of methanedisulfonic acid bis(2-fluoro phenyl amide) (compound 6)

(23) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N-(2-fluorophenyl)amine (12.2 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(24) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(2-fluoro phenyl amide) (4.6 g) (0.013 mol). The yield of the methanedisulfonic acid bis(2-fluoro phenyl amide) was 25.4% based on the amount of the methanedisulfonyl chloride.

(25) The resulting methanedisulfonic acid bis(2-fluoro phenyl amide) was identified by its properties described below.

(26) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.52-7.58 (m, 2H), 7.49 (d, 2H), 7.14-7.28 (m, 6H), 4.51 (s, 2H)

EXAMPLE 7

Preparation of methanedisulfonic acid bis(4-fluorobenzyl amide) (compound 7)

(27) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N-(4-fluorobenzyl)amine (13.8 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added over 1 hour, followed by stirring over night at the same temperature.

(28) After the completion of the reaction, the reaction solution was filtered, and to the resulting filtrate were added toluene (150.0 g), water (80.0 g), and 1,2-dimethoxyethane (70.0 g). Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(4-fluorobenzyl amide) (5.6 g) (0.014 mol). The yield of the methanedisulfonic acid bis(4-fluorobenzyl amide) was 28.7% based on the amount of the methanedisulfonyl chloride.

(29) The resulting methanedisulfonic acid bis(4-fluorobenzyl amide) was identified by its properties described below.

(30) .sup.1H-nuclear magnetic resonance spectrum (solvent: Acetone-D.sub.6) (ppm): 7.43-7.50 (m, 4H), 7.20-7.27 (m, 4H), 6.9 (s, 2H), 4.79 (s, 2H), 4.39 (d, 4H)

EXAMPLE 8

Preparation of 1,1-ethanedisulfonic acid bis(methyl phenyl amide) (compound 8)

(31) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-methylphenyl amine (11.8 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of 1,1-ethane disulfonyl chloride (11.4 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(32) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give 1,1-ethanedisulfonic acid bis(methyl phenyl amide) (4.6 g) (0.013 mol). The yield of the 1,1-ethanedisulfonic acid bis(methyl phenyl amide) was 25.1% based on the amount of the 1,1-ethane disulfonyl chloride.

(33) The resulting 1,1-ethanedisulfonic acid bis(methyl phenyl amide) was identified by its properties described below.

(34) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.30-7.41 (m, 10H), 4.68 (q, 1H), 2.75 (s, 6H), 1.72 (d, 3H)

EXAMPLE 9

Preparation of 1,1-ethanedisulfonic acid bis(benzyl methyl amide) (compound 9)

(35) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-benzylmethylamine (13.3 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of 1,1-ethane disulfonyl chloride (11.4 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(36) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give 1,1-ethanedisulfonic acid bis(benzyl methyl amide) (5.4 g) (0.014 mol). The yield of the 1,1-ethanedisulfonic acid bis(benzyl methyl amide) was 27.0% based on the amount of the 1,1-ethane disulfonyl chloride.

(37) The resulting 1,1-ethanedisulfonic acid bis(benzyl methyl amide) was identified by its properties described below.

(38) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.06-7.14 (m, 10H), 4.67 (q, 1H), 3.81 (s, 4H), 2.69 (s, 6H), 1.70 (d, 3H)

EXAMPLE 10

Preparation of 1,2-ethanedisulfonic acid bis(methyl phenyl amide) (compound 10)

(39) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-methylphenyl amine (11.8 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of 1,2-ethane disulfonyl chloride (11.4 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(40) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give 1,2-ethanedisulfonic acid bis(methyl phenyl amide) (6.0 g) (0.016 mol). The yield of the 1,2-ethanedisulfonic acid bis(methyl phenyl amide) was 32.3% based on the amount of the 1,2-ethane disulfonyl chloride.

(41) The resulting 1,2-ethanedisulfonic acid bis(methyl phenyl amide) was identified by its properties described below.

(42) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.19-7.26 (m, 10H), 3.97 (d, 4H), 2.80 (s, 6H)

EXAMPLE 11

Preparation of 2-oxopropane-1,1-disulfonic acid bis(methyl phenyl amide) (compound 11)

(43) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(methyl phenyl amide) (17.9 g) (0.05 mol) prepared by the same manner as in Example 2 and dichloromethane (70.0 g), and 60% by mass sodium hydride (2.2 g) (0.055 mol) was added thereto at 0 C. The contents were allowed to stand for 1 hour. Subsequently, while maintaining the temperature at 0 C., to the contents were added dropwise triethylamine (10.6 g) (0.10 mol) and a solution of acetyl chloride (0.5 g) (0.06 mol) dissolved in dichloromethane (20.0 g) over 1 hour, followed by stirring over night at the same temperature.

(44) After the completion of the reaction, the reaction solution was filtered, and dichloromethane (50.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give 2-oxopropane-1,1-disulfonic acid bis(methyl phenyl amide) (3.9 g) (0.010 mol). The yield of the 2-oxopropane-1,1-disulfonic acid bis(methyl phenyl amide) was 19.5% based on the amount of the methanedisulfonic acid bis(methyl phenyl amide).

(45) The resulting 2-oxopropane-1,1-disulfonic acid bis(methyl phenyl amide) was identified by its properties described below.

(46) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 6.89-7.27 (m, 10H), 5.35 (s, 1H), 2.81 (s, 6H), 2.09 (s, 3H)

EXAMPLE 12

Preparation of ,-bis((methylphenylamino)sulfonyl)acetophenone (compound 12)

(47) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(methyl phenyl amide) (17.9 g) (0.05 mol) prepared by the same manner as in Example 2 and dichloromethane (70.0 g), and 60% by mass sodium hydride (2.2 g) (0.055 mol) was added at 0 C. The contents were allowed to stand for 1 hour. Subsequently, while maintaining the temperature at 0 C., to the contents were added dropwise triethylamine (10.6 g) (0.10 mol) and a solution of benzoyl chloride (8.4 g) (0.06 mol) dissolved in dichloromethane (20.0 g) over 1 hour, followed by stirring over night at the same temperature.

(48) After the completion of the reaction, the reaction solution was filtered, and dichloromethane (50.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give ,-bis(methylphenylamino sulfonyl)acetophenone (6.0 g) (0.013 mol). The yield of the ,-bis(methylphenylamino sulfonyl)acetophenone was 26.3% based on the amount of the methanedisulfonic acid bis(methyl phenyl amide).

(49) The resulting (,-bis((methylphenylamino)sulfonyl)acetophenone was identified by its properties described below.

(50) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 6.84-7.86 (m, 15H), 6.10 (s, 1H), 2.79 (s, 6H)

EXAMPLE 13

Preparation of 2,2-bis((methylphenylamino)sulfonyl)acetonitrile (compound 13)

(51) To a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was added dropwise chlorosulfonic acid (23.3 g) (0.2 mol) mixed with phosphoryl chloride (46 g) over 1 hour, followed by dropwise addition of cyanoacetic acid (0.85 g) (0.1 mol) over 1 hour. The contents were heated to 100 C. over 2 hours, and stirred for 20 hours at the same temperature. Then, normal pressure distillation was carried out to remove phosphoryl chloride, and reduced pressure distillation was carried out to prepare cyano methanedisulfonyl chloride (14.2 g).

(52) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-methylphenyl amine (11.8 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of cyano methanedisulfonyl chloride (11.9 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(53) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give 2,2-bis(methylphenylamino sulfonyl)acetonitrile (5.4 g) (0.014 mol). The yield of the 2,2-bis(methylphenylamino sulfonyl)acetonitrile was 28.5% based on the amount of the cyano methanedisulfonyl chloride.

(54) The resulting 2,2-bis((methylphenylamino)sulfonyl)acetonitrile was identified by its properties described below.

(55) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 6.93-7.24 (m, 10H), 5.50 (s, 1H), 2.78 (s, 6H)

EXAMPLE 14

Preparation of bis((methylphenylamino)sulfonyl)nitromethane (compound 14)

(56) To a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was added dropwise chlorosulfonic acid (23.3 g) (0.2 mol) mixed with phosphoryl chloride (46 g) over 1 hour, followed by dropwise addition of nitro-acetic acid (10.5 g) (0.1 mol) over 1 hour. The contents were heated to 100 C. over 2 hours, and stirred for 20 hours at the same temperature. Then, normal pressure distillation was carried out to remove phosphoryl chloride, and reduced pressure distillation was carried out to prepare nitro methanedisulfonyl chloride (15.5 g).

(57) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-methylphenyl amine (11.8 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of nitro methanedisulfonyl chloride (12.9 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise thereto over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.6 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(58) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give bis(methylphenylamino sulfonyl)nitromethane (5.1 g) (0.013 mol). The yield of the bis(methylphenylamino sulfonyl)nitromethane was 25.4% based on the amount of the nitro methanedisulfonyl chloride.

(59) The resulting bis((methylphenylamino)sulfonyl)nitromethane was identified by its properties described below.

(60) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 6.88-7.15 (m, 10H), 5.89 (s, 1H), 2.77 (s, 6H)

EXAMPLE 15

Preparation of trimethyl bis((methylphenylamino)sulfonyl)methylsilane (compound 15)

(61) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(methyl phenyl amide) (17.9 g) (0.05 mol) prepared by the same manner as in Example 2 and dichloromethane (70.0 g), and 60% by mass sodium hydride (2.2 g) (0.055 mol) was added thereto at 0 C. The contents were allowed to stand for 1 hour. Subsequently, while maintaining the temperature at 0 C., to the contents were added dropwise triethylamine (10.6 g) (0.10 mol) and a solution of trimethyl silyl chloride (6.5 g) (0.06 mol) dissolved in dichloromethane (20.0 g) over 1 hour, followed by stirring over night at the same temperature.

(62) After the completion of the reaction, the reaction solution was filtered, and dichloromethane (50.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give trimethyl bis(methylphenylamino sulfonyl)methylsilane (4.5 g) (0.011 mol). The yield of the trimethyl bis(methylphenylamino sulfonyl)methylsilane was 20.1% based on the amount of the methanedisulfonic acid bis(methyl phenyl amide).

(63) The resulting trimethyl bis((methylphenylamino)sulfonyl)methylsilane was identified by its properties described below.

(64) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 6.99-7.27 (m, 10H), 5.85 (s, 1H), 2.74 (s, 6H), 0.00 (s, 9H)

COMPARATIVE EXAMPLE 1

Preparation of methanedisulfonic acid bis(ethylamide) (compound 16)

(65) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with ethyl amine (5.0 g) (0.11 mol) and 1,2-dimethoxyethane (70.0 g), and a solution of methanedisulfonyl chloride (10.7 g) (0.05 mol) dissolved in 1,2-dimethoxyethane (20.0 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., triethylamine (10.6 g) (0.10 mol) mixed with 1,2-dimethoxyethane (20.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(66) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the resulting organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(ethylamide) (2.5 g) (0.011 mol). The yield of the methanedisulfonic acid bis(ethylamide) was 21.4% based on the amount of the methanedisulfonyl chloride.

COMPARATIVE EXAMPLE 2

Preparation of methanedisulfonic acid bis(n-propylamide) (compound 17)

(67) Comparative Example 2 was performed in the same manner as in Comparative Example 1 except that n-propyl amine (6.5 g) (0.11 mol) was used instead of ethyl amine (5.0 g) (0.11 mol). Thus, methanedisulfonic acid bis(n-propylamide) (4.3 g) (0.017 mol, yield of 33.4%) was obtained.

COMPARATIVE EXAMPLE 3

Preparation of methanedisulfonic acid bis(isopropylamide) (compound 18)

(68) Comparative Example 3 was performed in the same manner as in Comparative Example 1 except that diisopropyl amine (11.1 g) (0.11 mol) was used instead of ethyl amine (5.0 g) (0.11 mol). Thus, methanedisulfonic acid bis(isopropylamide) (5.1 g) (0.015 mol, yield of 30.0%) was obtained.

COMPARATIVE EXAMPLE 4

Preparation of methanedisulfonic acid bis(n-butyramide) (compound 19)

(69) Comparative Example 4 was performed in the same manner as in Comparative Example 1 except that n-butyl amine (8.0 g) (0.11 mol) was used instead of ethyl amine (5.0 g) (0.11 mol). Thus, methanedisulfonic acid bis(n-butyramide) (4.2 g) (0.015 mol, yield of 29.1%) was obtained.

COMPARATIVE EXAMPLE 5

(70) Fluoroethylene carbonate (FEC), which is commonly used as an additive for lithium-ion batteries and the like, was prepared as an additive for a non-aqueous electrolyte solution.

(71) <Evaluation>

(72) (LUMO energy, standard enthalpy of formation (H), enthalpy change (H) with hydrolysis reaction)

(73) The LUMO (lowest unoccupied molecular orbital) energies of the compounds 1 to 15 obtained in Examples 1 to 15, respectively, and the compounds 16 to 19 obtained in Comparative Examples 1 to 4, respectively, were derived using the Gaussian 03 software. The results are shown in Tables 1 and 2.

(74) Further, the standard enthalpies of formation (H) of the compounds 1 to 15 obtained in Examples 1 to 15, respectively, and the compounds 16 to 19 obtained in Comparative Examples 1 to 4, respectively, were derived using the MOPAC 97 software. The results are shown in Tables 1 and 2.

(75) Further, the enthalpy changes (H) with hydrolysis reaction of the compounds 1 to 15 obtained in Examples 1 to 15, respectively, and the compounds 16 to 19 obtained in Comparative Examples 1 to 4, respectively, were derived using the Gaussian 03 software. The results are shown in Tables 1 and 2.

(76) TABLE-US-00001 TABLE 1 LUMO energy H H Cpd. Structure (eV) (kcal/mol) (kcal/mol) 1 0.62 74.6 4.7 2 0.63 56.2 3.0 3 0.47 90.6 1.7 4 0 0.65 59.3 2.5 5 0.71 75.6 4.3 6 0.76 68.3 4.5 7 0.50 95.3 3.6 8 0.73 58.3 2.3 9 0.45 62.3 2.0 10 0.61 90.4 2.6 11 1.51 78.6 2.1 12 2.34 86.3 3.8 13 1.12 98.1 2.5 14 0 2.84 85.7 3.4 15 0.70 102.8 4.1

(77) TABLE-US-00002 TABLE 2 LUMO H H energy (kcal/ (kcal/ Cpd. Structure (eV) mol) mol) 16 0.61 154.7 3.0 17 0.63 170.2 2.7 18 0.48 178.9 3.4 19 0.62 176.3 2.4

(78) Table 1 shows that the disulfonic acid amide compounds (compounds 1 to 15) represented by the formula (3) have a negative LUMO energy of about 0.45 eV to about 2.84 eV, and these disulfonic acid amide compounds according to the additive for a non-aqueous electrolyte solution of the present invention have a low LUMO energy. Therefore, in cases where the compounds 1 to 15 are used as an additive for a non-aqueous electrolyte solution for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the compounds 1 to 15 are electrochemically reduced prior to electrochemical reduction of solvents of non-aqueous electrolyte solutions (for example, cyclic carbonate and chain carbonate: LUMO energy of about 1.2 eV) and an SEI is formed on an electrode, whereby decomposition of solvent molecules in an electrolyte solution can be suppressed. As a result, a high resistant film produced by decomposition of the solvent is less likely to be formed on an electrode to probably improve cell performance.

(79) On the other hand, Table 2 shows that the disulfonic acid amide compounds (compounds 16 to 19) other than the disulfonic acid amide compounds represented by the formula (3) have a high LUMO energy of about 0.48 eV to about 0.63 eV. Therefore, the compounds 16 to 19 are relatively stable to electrochemical reduction and an SEI is less likely to be formed on an electrode.

(80) Table 1 shows that the disulfonic acid amide compounds (compounds 1 to 15) represented by the formula (3) have a standard enthalpy of formation (H) of about 56.2 kcal/mol to about 102.8 kcal/mol. That is, the compounds 1 to 15 according to the present invention have excellent storage stability in a non-aqueous electrolyte solution. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on the surface of an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(81) Table 1 further shows that the disulfonic acid amide compounds (compounds 1 to 15) represented by the formula (3) have an enthalpy change (H) with hydrolysis reaction of about 1.7 kcal/mol to about 4.7 kcal/mol. That is, the compounds 1 to 15 according to the present invention are also stable to moisture. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(82) Thus, the disulfonic acid amide compounds represented by the formula (3) according to the additive for a non-aqueous electrolyte solution of the present invention have a sufficiently low LUMO energy, excellent storage stability when contained in a non-aqueous electrolyte solution as an additive for a non-aqueous electrolyte solution, and excellent stability to moisture. This shows that such compounds are effective as a novel additive for a non-aqueous electrolyte solution capable of forming a stable SEI on an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(83) (Evaluation of Stability)

(84) The compounds 1 to 15 obtained in Examples 1 to 15, respectively, the compounds 16 to 19 obtained in Comparative Examples 1 to 4, respectively, and fluoroethylene carbonate (FEC) of Comparative Example 5 were subjected to a storage test for 90 days under constant temperature and humidity conditions of a temperature of 402 C. and humidity of 755%. The degradability of each compound was measured with .sup.1H-nuclear magnetic resonance spectrum (.sup.1H-NMR) and evaluated. Table 3 shows the results. Good: There is no change in peaks in .sup.1H-NMR before and after storage. Fair: There is a slight change in peaks in .sup.1H-NMR before and after storage. Poor: There is an obvious change in peaks in .sup.1H-NMR before and after storage.

(85) TABLE-US-00003 TABLE 3 Additive Stability Example 1 Compound 1 Good Example 2 Compound 2 Good Example 3 Compound 3 Good Example 4 Compound 4 Good Example 5 Compound 5 Good Example 6 Compound 6 Good Example 7 Compound 7 Good Example 8 Compound 8 Good Example 9 Compound 9 Good Example 10 Compound 10 Good Example 11 Compound 11 Good Example 12 Compound 12 Good Example 13 Compound 13 Good Example 14 Compound 14 Good Example 15 Compound 15 Good Comparative Compound 16 Fair Example 1 Comparative Compound 17 Fair Example 2 Comparative Compound 18 Fair Example 3 Comparative Compound 19 Fair Example 4 Comparative FEC Poor Example 5

(86) As shown in Table 3, fluoroethylene carbonate (FEC) of Comparative Example 5 is partly hydrolyzed and has poor stability. On the other hand, little change is observed in the disulfonic acid amide compounds obtained in Examples 1 to 15 and such compounds have excellent stability.

(87) (Measurement of LSV (Linear Sweep Voltammetry))

(88) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 was dissolved as an electrolyte in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution, and a compound of each of the examples and comparative examples was added thereto as an additive for a non-aqueous electrolyte solution in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared. Polarization was measured in a potential scanning rate of 5 mV/sec using the resulting non-aqueous electrolyte solution, a disk electrode made from glassy carbon as an electrode, and platinum as a counter electrode. A reduction starting voltage was calculated using a silver electrode as a reference electrode, in which the potential with respect to the reference electrode when 100 A of current flows was defined as oxidation potential and the potential with respect to the reference electrode when 100 A of current flows was defined as reduction potential. Further, as Reference Example 1, a reduction starting voltage was similarly calculated using a non-aqueous electrolyte solution prepared without adding an additive for a non-aqueous electrolyte solution. Table 4 shows the results.

(89) TABLE-US-00004 TABLE 4 LSV Reduction starting Electrolyte Solvent Additive voltage (V) Example 1 LiPF.sub.6 EC/DEC Compound 1 3.2 1.0 mol/L (30/70) vol % 1.0% by mass Example 2 LiPF.sub.6 EC/DEC Compound 2 3.1 1.0 mol/L (30/70) vol % 1.0% by mass Example 3 LiPF.sub.6 EC/DEC Compound 3 3.2 1.0 mol/L (30/70) vol % 1.0% by mass Example 4 LiPF.sub.6 EC/DEC Compound 4 3.0 1.0 mol/L (30/70) vol % 1.0% by mass Example 5 LiPF.sub.6 EC/DEC Compound 5 2.7 1.0 mol/L (30/70) vol % 1.0% by mass Example 6 LiPF.sub.6 EC/DEC Compound 6 2.9 1.0 mol/L (30/70) vol % 1.0% by mass Example 7 LiPF.sub.6 EC/DEC Compound 7 2.8 1.0 mol/L (30/70) vol % 1.0% by mass Example 8 LiPF.sub.6 EC/DEC Compound 8 2.8 1.0 mol/L (30/70) vol % 1.0% by mass Example 9 LiPF.sub.6 EC/DEC Compound 9 2.9 1.0 mol/L (30/70) vol % 1.0% by mass Example 10 LiPF.sub.6 EC/DEC Compound 10 2.8 1.0 mol/L (30/70) vol % 1.0% by mass Example 11 LiPF.sub.6 EC/DEC Compound 11 2.7 1.0 mol/L (30/70) vol % 1.0% by mass Example 12 LiPF.sub.6 EC/DEC Compound 12 2.7 1.0 mol/L (30/70) vol % 1.0% by mass Example 13 LiPF.sub.6 EC/DEC Compound 13 2.9 1.0 mol/L (30/70) vol % 1.0% by mass Example 14 LiPF.sub.6 EC/DEC Compound 14 3.0 1.0 mol/L (30/70) vol % 1.0% by mass Example 15 LiPF.sub.6 EC/DEC Compound 15 2.8 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 16 3.6 Example 1 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 17 3.5 Example 2 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 18 3.6 Example 3 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 19 3.6 Example 4 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 3.3 Example 5 1.0 mol/L (30/70) vol % 1.0% by mass Reference LiPF.sub.6 EC/DEC None 3.6 Example 1 1.0 mol/L (30/70)vol %

(90) Table 4 shows that the non-aqueous electrolyte solutions each containing a disulfonic acid amide compound obtained in each of the examples have a higher reduction starting voltage than the non-aqueous electrolyte solutions each containing a compound of each of the comparative examples. Therefore, in cases where a non-aqueous electrolyte solution containing an additive for a non-aqueous electrolyte solution formed from a disulfonic acid amide compound prepared in each of the examples is used for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the disulfonic acid amide compound according to the present invention is electrochemically reduced prior to electrochemical reduction of the non-aqueous electrolyte solution of Reference Example 1 and non-aqueous electrolyte solutions each containing a compound of each of the comparative examples, and a stable SEI is easily formed on the surface of an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(91) (Preparation of Cell)

(92) Each of the cathode active materials according to Tables 5 to 8 and a carbon black as a conductivity imparting agent were dry mixed, and the mixture was uniformly dispersed in N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride (PVDF) was dissolved as a binder to prepare a slurry. The resulting slurry was applied to an aluminum foil (square, thickness of 20 m) that is to be a cathode current collector, and the NMP was dried off to prepare a cathode sheet. The resulting cathode sheet had a solid mass ratio of cathode active material:conductivity imparting agent:PVDF=80:10:10.

(93) On the other hand, a commercially available graphite-coated electrode sheet (produced by Hohsen Corp.) was used as an anode sheet.

(94) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. A compound of each of the examples and comparative examples was added thereto as an additive for a non-aqueous electrolyte solution in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

(95) A cylindrical secondary battery was prepared in such a way that an anode sheet and a cathode sheet were laminated and a polyethylene separator was disposed between the sheets in the resulting non-aqueous electrolyte solution. Further, as Reference Example 1, a cylindrical secondary battery was similarly prepared using a non-aqueous electrolyte solution prepared without adding an additive for a non-aqueous electrolyte solution.

(96) (Evaluation of Cycle Performance)

(97) The resulting cylindrical secondary batteries were subjected to a charge/discharge cycle test under the conditions of a temperature of 25 C., a charging rate of 0.3 C, a discharging rate of 0.3 C, a charge termination voltage of 4.2 V, and a discharge termination voltage of 2.5 V. Tables 5 to 8 show discharge capacity retentions (%) after 200 cycles.

(98) The discharge capacity retention (%) after 200 cycles was determined by dividing the discharge capacity (mAh) after 200 cycles of the cycle test by the discharge capacity (mAh) after 10 cycles of the cycle test and multiplying the resulting value by 100.

(99) TABLE-US-00005 TABLE 5 Cathode Discharge capacity active material Additive retention (%) Example 1 LiMn.sub.2O.sub.4 Compound 1 90 Example 2 LiMn.sub.2O.sub.4 Compound 2 91 Example 3 LiMn.sub.2O.sub.4 Compound 3 92 Example 4 LiMn.sub.2O.sub.4 Compound 4 91 Example 5 LiMn.sub.2O.sub.4 Compound 5 90 Example 6 LiMn.sub.2O.sub.4 Compound 6 90 Example 7 LiMn.sub.2O.sub.4 Compound 7 90 Example 8 LiMn.sub.2O.sub.4 Compound 8 92 Example 9 LiMn.sub.2O.sub.4 Compound 9 92 Example 10 LiMn.sub.2O.sub.4 Compound 10 91 Example 11 LiMn.sub.2O.sub.4 Compound 11 90 Example 12 LiMn.sub.2O.sub.4 Compound 12 93 Example 13 LiMn.sub.2O.sub.4 Compound 13 90 Example 14 LiMn.sub.2O.sub.4 Compound 14 93 Example 15 LiMn.sub.2O.sub.4 Compound 15 91 Comparative LiMn.sub.2O.sub.4 Compound 16 78 Example 1 Comparative LiMn.sub.2O.sub.4 Compound 17 77 Example 2 Comparative LiMn.sub.2O.sub.4 Compound 18 80 Example 3 Comparative LiMn.sub.2O.sub.4 Compound 19 76 Example 4 Comparative LiMn.sub.2O.sub.4 FEC 82 Example 5 Reference LiMn.sub.2O.sub.4 None 74 Example 1

(100) TABLE-US-00006 TABLE 6 Cathode Discharge capacity active material Additive retention (%) Example 1 LiCoO.sub.2 Compound 1 91 Example 2 LiCoO.sub.2 Compound 2 92 Example 3 LiCoO.sub.2 Compound 3 92 Example 4 LiCoO.sub.2 Compound 4 93 Example 5 LiCoO.sub.2 Compound 5 88 Example 6 LiCoO.sub.2 Compound 6 90 Example 7 LiCoO.sub.2 Compound 7 89 Example 8 LiCoO.sub.2 Compound 8 90 Example 9 LiCoO.sub.2 Compound 9 92 Example 10 LiCoO.sub.2 Compound 10 92 Example 11 LiCoO.sub.2 Compound 11 94 Example 12 LiCoO.sub.2 Compound 12 90 Example 13 LiCoO.sub.2 Compound 13 88 Example 14 LiCoO.sub.2 Compound 14 94 Example 15 LiCoO.sub.2 Compound 15 89 Comparative LiCoO.sub.2 Compound 16 73 Example 1 Comparative LiCoO.sub.2 Compound 17 74 Example 2 Comparative LiCoO.sub.2 Compound 18 79 Example 3 Comparative LiCoO.sub.2 Compound 19 73 Example 4 Comparative LiCoO.sub.2 FEC 81 Example 5 Reference LiCoO2 None 71 Example 1

(101) TABLE-US-00007 TABLE 7 Cathode Discharge capacity active material Additive retention (%) Example 1 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 1 90 Example 2 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 2 92 Example 3 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 3 91 Example 4 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 4 91 Example 5 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 5 89 Example 6 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 6 90 Example 7 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 7 88 Example 8 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 8 89 Example 9 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 9 91 Example 10 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 10 92 Example 11 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 11 93 Example 12 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 12 92 Example 13 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 13 91 Example 14 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 14 90 Example 15 LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 15 88 Comparative LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 16 69 Example 1 Comparative LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 17 67 Example 2 Comparative LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 18 77 Example 3 Comparative LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 Compound 19 69 Example 4 Comparative LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 FEC 80 Example 5 Reference LiNi.sub.1/3Co.sub.1/3Mn.sub.1/3O.sub.2 None 65 Example 1

(102) TABLE-US-00008 TABLE 8 Cathode Discharge capacity active material Additive retention (%) Example 1 LiFePO.sub.4 Compound 1 90 Example 2 LiFePO.sub.4 Compound 2 91 Example 3 LiFePO.sub.4 Compound 3 92 Example 4 LiFePO.sub.4 Compound 4 92 Example 5 LiFePO.sub.4 Compound 5 91 Example 6 LiFePO.sub.4 Compound 6 91 Example 7 LiFePO.sub.4 Compound 7 90 Example 8 LiFePO.sub.4 Compound 8 91 Example 9 LiFePO.sub.4 Compound 9 92 Example 10 LiFePO.sub.4 Compound 10 90 Example 11 LiFePO.sub.4 Compound 11 95 Example 12 LiFePO.sub.4 Compound 12 92 Example 13 LiFePO.sub.4 Compound 13 93 Example 14 LiFePO.sub.4 Compound 14 92 Example 15 LiFePO.sub.4 Compound 15 90 Comparative LiFePO.sub.4 Compound 16 78 Example 1 Comparative LiFePO.sub.4 Compound 17 80 Example 2 Comparative LiFePO.sub.4 Compound 18 86 Example 3 Comparative LiFePO.sub.4 Compound 19 79 Example 4 Comparative LiFePO.sub.4 FEC 83 Example 5 Reference LiFePO.sub.4 None 78 Example 1

(103) Tables 5 to 8 show that the cylindrical secondary batteries each using a non-aqueous electrolyte solution containing a disulfonic acid amide compound prepared in each of Examples 1 to 15 have a higher discharge capacity retention in a cycle test than the cylindrical secondary batteries each using the non-aqueous electrolyte solution of Reference Example 1 or a non-aqueous electrolyte solution containing a compound of each of the comparative examples. Therefore, in electrical storage devices such as non-aqueous electrolyte solution secondary cells, the non-aqueous electrolyte solutions each containing an additive for a non-aqueous electrolyte solution formed from a disulfonic acid amide compound obtained in each of the examples provide an SEI with higher stability to charge/discharge cycle on the surface of an electrode than the non-aqueous electrolyte solution of Reference Example 1 and the non-aqueous electrolyte solutions each containing a compound of each of the comparative examples.

EXAMPLE 16

Preparation of 2,5-Diphenyl-[1,6,2,5]dithiadiazepane 1,1,6,6-tetraoxide (compound 20: cyclic cisulfonic acid amide compound represented by the formula (12))

(104) A 300-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with N,N-diphenylethylenediamine (4.25 g) (0.020 mol) and dichloromethane (120.0 g), and methanedisulfonyl chloride (4.26 g) (0.020 mol) mixed with dichloromethane (40.0 g) was added dropwise over 1 hour while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (4.5 g) (0.044 mol) dissolved in dichloromethane (40.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(105) After the completion of the reaction, the reaction solution was filtered, and toluene (200.0 g) and water (100.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried. The dried crystals were recrystalized using dichloromethane and heptane, collected by filtration, and dried to give a compound 20 (cyclic disulfonic acid amide compound represented by the formula (12)) (1.8 g) (0.005 mol). The yield of the resulting compound 20 was 25.0% based on the amount of the methanedisulfonyl chloride.

(106) The resulting compound 20 was identified by its properties described below.

(107) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.63-7.65 (m, 4H), 7.45-7.49 (m, 4H), 7.41-7.42 (m, 2H), 5.20 (s, 2H), 4.18 (s, 4H) LC/MS (m/z [M-H]+): 351

EXAMPLE 17

Preparation of 5,9-Dihydro-6,8-dithia-5,9-diaza-benzocycloheptene 6,6,8,8-tetraoxide (compound 21: cyclic disulfonic acid amide compound represented by the formula (13))

(108) A 500-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 1,2-dimethoxyethane (140.0 g), and a solution of methanedisulfonyl chloride (21.3 g) (0.10 mol) dissolved in 1,2-dimethoxyethane (80.0 g) and a solution of o-phenylenediamine (11.9 g) (0.11 mol) dissolved in 1,2-dimethoxyethane (80.0 g) were simultaneously added dropwise over 1 hour while maintaining the temperature at 20 C. Subsequently, while maintaining the temperature at 20 C., a solution of triethylamine (21.3 g) (0.21 mol) dissolved in 1,2-dimethoxyethane (50.0 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(109) After the completion of the reaction, the reaction solution was filtered, and toluene (200.0 g) and water (100.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. After repulping with dichloromethane (200.0 g), the crystals were collected by filtration, and dried. The dried crystals were recrystalized with methanol and toluene, collected by filtration, and dried to give a compound 21 (cyclic disulfonic acid amide compound represented by the formula (13)) (4.8 g) (0.019 mol). The yield of the compound 21 was 19.1% based on the amount of the methanedisulfonyl chloride.

(110) The resulting compound 21 was identified by its properties described below.

(111) .sup.1H-nuclear magnetic resonance spectrum (solvent: CD.sub.3CN) (ppm): 8.05 (s, 2H), 7.36-7.37 (m, 2H), 7.26-7.27 (m, 2H), 5.03 (s, 2H) LC/MS (m/z [M-H]+): 247

COMPARATIVE EXAMPLE 6

(112) 1,3-propane sultone (PS) (produced by Aldrich) was used as a compound 22.

COMPARATIVE EXAMPLE 7

Preparation of ethylene methanedisulfonate (compound 23)

(113) A compound 23 (ethylene methanedisulfonate) (1.11 g) (0.0055 mol) was prepared in the same manner as in Example 16 except that ethylene glycol (1.24 g) (0.020 mol) was used instead of N,N-diphenylethylenediamine (4.25 g) (0.020 mol). The yield of the compound 23 was 27.5% based on the amount of the methanedisulfonyl chloride.

COMPARATIVE EXAMPLE 8

Preparation of 2,3-Dimethyl-[1,4,2,3]dithiadiazolidine 1,1,4,4-tetraoxide (compound 24)

(114) A compound 24 (2,3-dimethyl-[1,4,2,3]dithiadiazolidine 1,1,4,4-tetraoxide) (0.88 g) (0.0044 mol) was prepared in the same manner as in Example 16 except that N,N-dimethylhydrazine (1.20 g) (0.020 mol) was used instead of N,N-diphenylethylenediamine (4.25 g) (0.020 mol). The yield of the compound 24 was 22.0% based on the amount of the methanedisulfonyl chloride.

(115) <Evaluation>

(116) (LUMO energy, standard enthalpy of formation (H), enthalpy change (H) with hydrolysis reaction)

(117) The LUMO (lowest unoccupied molecular orbital) energies of the compounds 20 to 24 prepared in the examples and comparative examples were derived using the Gaussian 03 software. The results are shown in Table 9.

(118) Further, the standard enthalpies of formation (H) of the compounds 20 to 24 prepared in the examples and comparative examples were derived using the MOPAC 97 software. The results are shown in Table 9.

(119) Further, the enthalpy changes (H) with hydrolysis reaction of the compounds 20 to 24 prepared in the examples and comparative examples were derived using the Gaussian 03 software. The results are shown in Table 9.

(120) TABLE-US-00009 TABLE 9 LUMO H H energy (kcal/ (kcal/ Structure (eV) mol) mol) Compound 20 0.65 56.2 4.7 Compound 21 1.01 129.4 2.7 Compound 22 0.97 120.6 2.6 Compound 23 0.12 233.9 5.6 Compound 24 0 0.02 79.0 6.1

(121) Table 9 shows that the cyclic disulfonic acid amide compounds (compounds 20 and 21) represented by the formula (9) have a negative LUMO energy of about 0.65 eV to about 1.01 eV, and these cyclic disulfonic acid amide compounds according to the additive for a non-aqueous electrolyte solution of the present invention have a low LUMO energy. Therefore, in cases where the compounds 20 and 21 are used as an additive for a non-aqueous electrolyte solution in electrical storage devices such as non-aqueous electrolyte solution secondary cells, the compounds 20 and 21 are electrochemically reduced prior to electrochemical reduction of solvents of non-aqueous electrolyte solutions (for example, cyclic carbonate and chain carbonate: LUMO energy of about 1.2 eV), and an SEI is formed on an electrode, whereby decomposition of solvent molecules in an electrolyte solution can be suppressed. As a result, a high resistant film produced by decomposition of the solvent is less likely to be formed on an electrode to probably improve cell performance.

(122) On the other hand, Table 9 shows that commonly used 1,3-propane sultone (PS) (compound 22), ethylene methanedisulfonate (compound 23), and the cyclic disulfonic acid amide compound (compound 24) other than the cyclic disulfonic acid amide compounds represented by the formula (9) has a relatively high LUMO energy of about 0.12 eV to about 0.97 eV. That is, the compounds 22 to 24 are relatively stable to electrochemical reduction, and are less likely to form an SEI on an electrode.

(123) Table 9 shows that the cyclic disulfonic acid amide compounds (compounds 20 and 21) represented by the formula (9) have a standard enthalpy of formation (H) of about 56.2 kcal/mol to about 129.4 kcal/mol. That is, the compounds 20 and 21 according to the present invention have excellent storage stability in a non-aqueous electrolyte solution. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(124) Further, Table 9 shows that the cyclic disulfonic acid amide compounds (compounds 20 and 21) represented by the formula (9) have an enthalpy change (H) with hydrolysis reaction of about 2.7 kcal/mol to about 4.7 kcal/mol. That is, the compounds 20 and 21 according to the present invention are also stable to moisture. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(125) Thus, the cyclic disulfonic acid amide compounds represented by the formula (9) according to the additive for a non-aqueous electrolyte solution of the present invention have a sufficiently low LUMO energy, excellent storage stability when contained in a non-aqueous electrolyte solution as an additive for a non-aqueous electrolyte solution, and excellent stability to moisture. This shows that such compounds are effective as a novel additive for a non-aqueous electrolyte solution capable of forming a stable SEI on an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(126) (Measurement of LSV (linear sweep voltammetry))

(127) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. Each of the compounds 20 to 24 of the examples and comparative examples was added thereto as an additive for a non-aqueous electrolyte solution in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared. Polarization was measured in a potential scanning rate of 5 mV/sec using the resulting non-aqueous electrolyte solution, a disk electrode made from glassy carbon as an electrode, and platinum as a counter electrode. A reduction starting voltage was calculated using a silver electrode as a reference electrode, in which the potential with respect to the reference electrode when 100 A of current flows was defined as oxidation potential and the potential with respect to the reference electrode when 100 A of current flows was defined as reduction potential. Further, as Reference Example 2, a reduction starting voltage was similarly calculated using a non-aqueous electrolyte solution prepared without adding an additive for a non-aqueous electrolyte solution. Table 10 shows the results.

(128) TABLE-US-00010 TABLE 10 LSV Reduction starting Electrolyte Solvent Additive voltage (V) Example 16 LiPF.sub.6 EC/DEC Compound 20 2.8 1.0 mol/L (30/70) vol % 1.0% by mass Example 17 LiPF.sub.6 EC/DEC Compound 21 2.4 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 22 3.5 Example 6 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 23 3.2 Example 7 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 24 3.3 Example 8 1.0 mol/L (30/70) vol % 1.0% by mass Reference LiPF.sub.6 EC/DEC None 3.6 Example 2 1.0 mol/L (30/70)vol %

(129) Table 10 shows that the non-aqueous electrolyte solutions each containing a disulfonic acid amide compound of each of the examples have a higher reduction starting voltage than the non-aqueous electrolyte solutions each containing a compound of each of the comparative examples or the non-aqueous electrolyte solution of Reference Example 2. Therefore, in cases where a non-aqueous electrolyte solution containing an additive for a non-aqueous electrolyte solution formed from the cyclic disulfonic acid amide compound obtained in Example 16 or 17 is used, in electrical storage devices such as non-aqueous electrolyte solution secondary cells, the cyclic disulfonic acid amide compound according to the present invention is electrochemically reduced prior to electrochemical reduction of the solvent of the non-aqueous electrolyte solution of Reference Example 2 and the non-aqueous electrolyte solutions each containing a compound of each of Comparative Examples 6 to 8, and easily forms a stable SEI on the surface of an electrode of cells such as non-aqueous electrolyte solution secondary cells.

(130) (Preparation of Cell)

(131) LiMn.sub.2O.sub.4 as a cathode active material and a carbon black as a conductivity imparting agent were dry mixed, and the mixture was uniformly dispersed in N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride (PVDF) was dissolved as a binder to prepare a slurry. The resulting slurry was applied to an aluminum foil (square, thickness of 20 m) that is to be a cathode current collector, and the NMP was dried off to prepare a cathode sheet. The resulting cathode sheet had a solid mass ratio of cathode active material:conductivity imparting agent:PVDF=80:10:10.

(132) A commercially available graphite-coated electrode sheet (produced by Hohsen Corp.) was used as an anode sheet.

(133) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 was dissolved as an electrolyte in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution, a compound of each of the examples and comparative examples was added thereto as an additive for a non-aqueous electrolyte solution in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, non-aqueous electrolyte solution was prepared.

(134) A cylindrical secondary battery was prepared in such a way that an anode sheet and a cathode sheet were laminated and a polyethylene separator was disposed between the sheets in the resulting non-aqueous electrolyte solution. Further, as Reference Example 2, a cylindrical secondary battery was similarly prepared using the non-aqueous electrolyte solution prepared without adding an additive for a non-aqueous electrolyte.

(135) (Measurement of Discharge Capacity Retention and Internal Resistance Ratio)

(136) The resulting cylindrical secondary batteries were subjected to a charge/discharge cycle test under the conditions of a temperature of 25 C., a charging rate of 0.3 C, a discharging rate of 0.3 C, a charge termination voltage of 4.2 V, and a discharge termination voltage of 2.5 V. Table 11 shows discharge capacity retention (%) and internal resistance ratio after 200 cycles.

(137) The discharge capacity retention (%) after 200 cycles was determined by dividing the discharge capacity (mAh) after 200 cycles of the cycle test by the discharge capacity (mAh) after 10 cycles of the cycle test and multiplying the resulting value by 100. Further, the internal resistance ratio after 200 cycles was expressed as a value of the resistance after 200 cycles of the cycle test relative to a value of the resistance before the cycle test taken as 1.

(138) TABLE-US-00011 TABLE 11 Internal Discharge capacity resistance Electrolyte Solvent Additive retention (%) ratio Example 16 LiPF.sub.6 EC/DEC Compound 20 90 1.18 1.0 mol/L (30/70) vol % 1.0% by mass Example 17 LiPF.sub.6 EC/DEC Compound 21 92 1.21 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 22 77 1.68 Example 6 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 23 81 1.69 Example7 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 24 81 1.55 Example 8 1.0 mol/L (30/70) vol % 1.0% by mass Reference LiPF.sub.6 EC/DEC None 74 1.83 Example 2 1.0 mol/L (30/70)vol %

(139) Table 11 shows that the cylindrical secondary batteries each using a non-aqueous electrolyte solution containing a cyclic disulfonic acid amide compound prepared in each of the examples have a higher discharge capacity retention in a cycle test than the cylindrical secondary batteries each using a non-aqueous electrolyte solution containing a compound of each of the comparative examples or the non-aqueous electrolyte solution of Reference Example 2. Therefore, in cells such as non-aqueous electrolyte solution secondary cells, the non-aqueous electrolyte solutions containing an additive for a non-aqueous electrolyte solution formed from a cyclic disulfonic acid amide compound obtained in each of Examples 16 and 17 provide an SEI with higher stability to charge/discharge cycle on the surface of an electrode of the cells than the non-aqueous electrolyte solution of Reference Example 2 and the non-aqueous electrolyte solutions each containing a compound of each of Comparative Examples 6 to 8.

(140) Further, the non-aqueous electrolyte solutions each containing a cyclic disulfonic acid amide compound obtained in each of the examples have smaller internal resistance than the non-aqueous electrolyte solution of Reference Example 2 and the non-aqueous electrolyte solutions each containing a compound of each of the comparative examples, and therefore suppress an increase in internal resistance during a cycle test.

EXAMPLE 18

Preparation of phosphorus-containing sulfonic acid amide compound (compound 25) represented by the formula (15) in which R16 is ethyl, R17 is ethyl, R18 is methylene, R19 is methylene, X9 is methyl, X10 is methyl, and Y1 is hydrogen

(141) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with bromoacetic acid (13.9 g) (0.1 mol) and dimethoxyethane (70.0 g), and triethyl phosphite (16.6 g) (0.1 mol) mixed with dimethoxyethane (20.0 g) was added dropwise over 2 hours at 0 C. The temperature was gradually increased to room temperature. The solution was stirred over night and rinsed with water and a saturated saline. The dimethoxyethane was removed by distillation to give a reaction product (30 g).

(142) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with phosphoryl chloride (46 g), chlorosulfonic acid (23.3 g) (0.2 mol) was added dropwise over 1 hour, followed by dropwise addition of the resulting reaction product (30 g) over 1 hour. Then, the solution was heated to 100 C. over 2 hours and stirred 20 hours at the same temperature. Then, phosphoryl chloride was removed by normal pressure distillation to give an oily reaction product (25 g).

(143) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with dimethoxyethane (70 g) and N,N-diethylmethylenediamine (10.2 g) (0.1 mol), followed by cooling to 0 C. The resulting oily reaction product (25 g) was added dropwise thereto over 2 hours, followed by dropwise addition of triethylamine (30.4 g) (0.3 mol) over 2 hours. The contents were further stirred for 10 hours to complete the reaction. The reaction solution was filtered, and toluene (100 g) and water (25 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and the toluene was removed from the organic phase by reduced pressure distillation. Then, the remaining organic phase was cooled to 0 C. Methanol (40 g) was added dropwise thereto over 3 hours to give crystals. The crystals were filtered and dried under reduced pressure to give a phosphorus-containing sulfonic acid amide compound (compound 25) (5 g) represented by the formula (15) in which R.sup.16 was ethyl, R.sup.17 was ethyl, R.sup.18 was methylene, R.sup.19 was methylene, X.sup.9 was methyl, X.sup.10 was methyl, and Y.sup.1 was hydrogen. The yield of the compound 25 was 14% based on the amount of the bromoacetic acid.

(144) (Preparation of Non-Aqueous Electrolyte Solution)

(145) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 was dissolved as an electrolyte in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 25 prepared as an additive for a non-aqueous electrolyte solution was added thereto in an amount of 0.5% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 19

(146) A non-aqueous electrolyte solution was prepared in the same manner as in Example 18 except that the amount of the compound 25 was 1.0% by mass in Preparation of non-aqueous electrolyte solution.

EXAMPLE 20

Preparation of phosphorus-containing sulfonic acid amide compound (compound 26) represented by the formula (15) in which R16 is ethyl, R17 is ethyl, R18 and 1219 are omitted as C0 alkylene, X9 is phenyl, X10 is phenyl, and Y1 is hydrogen

(147) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with bromoacetic acid (13.9 g) (0.1 mol) and dimethoxyethane (70.0 g), and triethyl phosphite (16.6 g) (0.1 mol) mixed with dimethoxyethane (20.0 g) was added dropwise over 2 hours at 0 C. The contents were gradually heated to room temperature, stirred over night, and rinsed with water and a saturated saline. The dimethoxyethane was removed by distillation to give a reaction product (30 g).

(148) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with phosphoryl chloride (46 g), and chlorosulfonic acid (23.3 g) (0.2 mol) was added dropwise over 1 hour, followed by drowpise addition of the resulting reaction product (30 g) over 1 hour. Then, the contents were heated to 100 C. over 2 hours, and stirred for 20 hours at the same temperature. Then, phosphoryl chloride was removed by normal pressure distillation to give an oily reaction product (25 g).

(149) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with dimethoxyethane (70 g) and methylene dianilide (19.8 g) (0.10 mol), and the contents were cooled to 0 C. The resulting oily reaction product (25 g) was added dropwise over 2 hours, followed by dropwise addition of triethylamine (22.3 g) (0.22 mol) over 2 hours. The contents were stirred for 10 hours to complete the reaction. The reaction solution was filtered, and toluene (100 g) and water (25 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and the toluene was removed from the organic phase by reduced pressure distillation. Then, the remaining organic phase was cooled to 0 C. Methanol (40 g) was added dropwise thereto over 3 hours to give crystals. The crystals were filtered and dried under reduced pressure to give a phosphorus-containing sulfonic acid amide compound (compound 26) (5 g) represented by the formula (15) in which R.sup.16 was ethyl, R.sup.17 was ethyl, R.sup.18 and R.sup.19 were omitted as C0 alkylene, X.sup.9 was phenyl, X.sup.10 was phenyl, and Y.sup.1 was hydrogen. The yield of the compound 26 was 11% based on the amount of the bromoacetic acid.

(150) (Preparation of Non-Aqueous Electrolyte Solution)

(151) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 26 prepared as an additive for a non-aqueous electrolyte solution was added in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 21

Preparation of phosphorus-containing sulfonic acid amide compound (compound 27) represented by the formula (16) in which R16 is ethyl, R17 is ethyl, R18 and R19 are omitted as C0 alkylene, R23 is methyl, R24 is methyl, X9 is phenyl, X10 is phenyl, and Y1 is hydrogen

(152) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with bromoacetic acid (13.9 g) (0.1 mol) and dimethoxyethane (70.0 g), and triethyl phosphite (16.6 g) (0.1 mol) mixed with dimethoxyethane (20.0 g) was added dropwise over 2 hours at 0 C. The contents were gradually heated to room temperature, stirred over night, and rinsed with water and a saturated saline. The dimethoxyethane was removed by distillation to give a reaction product (30 g).

(153) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with phosphoryl chloride (46 g), and chlorosulfonic acid (23.3 g) (0.2 mol) was added dropwise over 1 hour, followed by dropwise addition of the resulting reaction product (30 g) over 1 hour. Then, the contents were heated to 100 C. over 2 hours and stirred for 20 hours at the same temperature. Then, phosphoryl chloride was removed by normal pressure distillation to give an oily reaction product (25 g).

(154) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with dimethoxyethane (70 g) and methylphenyl amine (21.4 g) (0.20 mol), and the contents were cooled to 0 C. The resulting oily reaction product (25 g) was added dropwise thereto over 2 hours, followed by dropwise addition of triethylamine (22.3 g) (0.22 mol) over 2 hours. Further, the contents were stirred for 10 hours to complete the reaction. The reaction solution was filtered, and toluene (100 g) and water (25 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and the toluene was removed from the organic phase by reduced pressure distillation. Then, the remaining organic phase was cooled to 0 C. Methanol (40 g) was added dropwise thereto over 3 hours to give crystals. The crystals were filtered and dried under reduced pressure to give a phosphorus-containing sulfonic acid amide compound (compound 27) (7 g) represented by the formula (16) in which R.sup.16 was ethyl, R.sup.17 was ethyl, R.sup.18 and R.sup.19 were omitted as C0 alkylene, R.sup.23 was methyl, R.sup.24 was methyl, X.sup.9 was phenyl, X.sup.10 was phenyl, and Y.sup.1 was hydrogen. The yield of the compound 27 was 14% based on the amount of the bromoacetic acid.

(155) (Preparation of Non-Aqueous Electrolyte Solution)

(156) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 27 prepared as an additive for a non-aqueous electrolyte solution was added in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 22

Preparation of phosphorus-containing sulfonic acid amide compound (compound 28) represented by the formula (16) in which R16 is ethyl, R17 is ethyl, R18 is methylene, R19 is methylene, R23 is methyl, R24 is methyl, X9 is phenyl, X10 is phenyl, and Y1 is hydrogen

(157) A phosphorus-containing sulfonic acid amide compound (compound 28) (6 g) represented by the formula (16) in which R.sup.16 was ethyl, R.sup.17 was ethyl, R.sup.18 was methylene, R.sup.19 was methylene, R.sup.23 was methyl, R.sup.24 was methyl, X.sup.9 was phenyl, X.sup.10 was phenyl, and Y.sup.1 was hydrogen was prepared in the same manner as in Example 21 except that benzylmethylamine (24.2 g) (0.20 mol) was used instead of methylphenyl amine (21.4 g) (0.20 mol). The yield of the compound 28 was 12% based on the amount of the bromoacetic acid.

(158) (Preparation of Non-Aqueous Electrolyte Solution)

(159) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 28 prepared as an additive for a non-aqueous electrolyte solution was added in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

COMPARATIVE EXAMPLE 9

(160) A non-aqueous electrolyte solution was prepared in the same manner as in Example 18 except that no compound 25 was used.

COMPARATIVE EXAMPLE 10

(161) A non-aqueous electrolyte solution was prepared in the same manner as in Example 19 except that 1,3-propane sultone (PS) was used instead of the compound 25.

COMPARATIVE EXAMPLE 11

(162) A non-aqueous electrolyte solution was prepared in the same manner as in Example 19 except that vinylene carbonate (VC) was used instead of the compound 25.

COMPARATIVE EXAMPLE 12

(163) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 11 except that the amount of the vinylene carbonate (VC) was 2.0% by mass.

COMPARATIVE EXAMPLE 13

(164) A non-aqueous electrolyte solution was prepared in the same manner as in Example 19 except that fluoroethylene carbonate (FEC) was used instead of the compound 25.

COMPARATIVE EXAMPLE 14

(165) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 13 except that the amount of the fluoroethylene carbonate (FEC) was 2.0% by mass.

(166) <Evaluation>

(167) (LUMO Energy, Standard Enthalpy of Formation (H), Enthalpy Change (H) with Hydrolysis Reaction)

(168) The LUMO (lowest unoccupied molecular orbital) energies of the compounds 25 to 28 prepared in the examples were derived using the Gaussian 03 software. The results are shown in Table 12.

(169) Further, the standard enthalpies of formation (H) of the compounds 25 to 28 prepared in the examples were derived using the MOPAC 97 software. The results are shown in Table 12.

(170) Further, the enthalpy changes (AH) with hydrolysis reaction of the compounds 25 to 28 prepared in the examples were derived using the Gaussian 03 software. The results are shown in Table 12.

(171) TABLE-US-00012 TABLE 12 LUMO H H energy (kcal/ (kcal/ Structure (eV) mol) mol) Com- pound 25 0.14 187.9 4.3 Com- pound 26 0.86 207.6 3.9 Com- pound 27 0.75 203.4 3.7 Com- pound 28 0.5 188.3 4.1

(172) Table 12 shows that the phosphorus-containing sulfonic acid amide compounds (compounds 25 to 28) represented by the formula (14) have a negative LUMO energy of about 0.14 eV to about 0.86 eV, and these phosphorus-containing sulfonic acid amide compounds according to the additive for a non-aqueous electrolyte solution of the present invention have a low LUMO energy. Therefore, in cases where the compounds 25 to 28 are used as an additive for a non-aqueous electrolyte solution for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the compounds 25 to 28 are electrochemically reduced prior to electrochemical reduction of solvents of non-aqueous electrolyte solutions (for example, cyclic carbonate and chain carbonate: LUMO energy of about 1.2 eV), and an SEI is formed on an electrode, whereby decomposition of solvent molecules in an electrolyte solution can be suppressed. As a result, a high resistant film produced by decomposition of the solvent is less likely to be formed on an electrode to probably improve cell performance.

(173) Table 12 shows that the phosphorus-containing sulfonic acid amide compounds (compounds 25 to 28) represented by the formula (14) have a standard enthalpy of formation (H) of about 187.9 kcal/mol to about 207.6 kcal/mol. That is, the compounds 25 to 28 according to the present invention have excellent storage stability in a non-aqueous electrolyte solution. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode.

(174) As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(175) Further, Table 12 shows that the phosphorus-containing sulfonic acid amide compounds (compounds 25 to 28) represented by the formula (14) have an enthalpy change (H) with hydrolysis reaction of about 3.7 kcal/mol to about 4.3 kcal/mol. That is, the compounds 25 to 28 according to the present invention are also stable to moisture. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on the surface of an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(176) Thus, the phosphorus-containing sulfonic acid amide compounds represented by the formula (14) according to the additive for a non-aqueous electrolyte solution of the present invention have a sufficiently low LUMO energy, excellent storage stability when contained in a non-aqueous electrolyte solution as an additive for a non-aqueous electrolyte solution, and excellent stability to moisture. This shows that such compounds are effective as a novel additive for a non-aqueous electrolyte solution capable of forming a stable SEI on an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(177) (Preparation of Cell)

(178) LiMn.sub.2O.sub.4 as a cathode active material and a carbon black as a conductivity imparting agent were dry mixed, and the mixture was uniformly dispersed in N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride (PVDF) was dissolved as a binder to prepare a slurry. The resulting slurry was applied to an aluminum foil (square, thickness of 20 m) that is to be a cathode current collector, and the NMP was dried off to prepare a cathode sheet. The resulting cathode sheet had a solid mass ratio of cathode active material: conductivity imparting agent:PVDF=80:10:10.

(179) A commercially available graphite-coated electrode sheet (produced by Hohsen Corp.) was used as an anode sheet.

(180) A cylindrical secondary battery was prepared in such a way that an anode sheet and a cathode sheet were laminated and a polyethylene separator was disposed between the sheets in a non-aqueous electrolyte solution prepared in each of the examples and comparative examples.

(181) (Measurement of Discharge Capacity Retention and Internal Resistance Ratio)

(182) The resulting cylindrical secondary batteries were subjected to a charge/discharge cycle test under the conditions of a temperature of 25 C., a charging rate of 0.3 C, a discharging rate of 0.3 C, a charge termination voltage of 4.2 V, and a discharge termination voltage of 2.5 V. Table 13 shows discharge capacity retention (%) and internal resistance ratio after 200 cycles. The discharge capacity retention (%) after 200 cycles was determined by dividing the discharge capacity (mAh) after 200 cycles of the cycle test by the discharge capacity (mAh) after 10 cycles of the cycle test and multiplying the resulting value by 100. Further, the internal resistance ratio after 200 cycles was expressed a value of the resistance after 200 cycles of the cycle test relative to a value of the resistance before the cycle test taken as 1.

(183) TABLE-US-00013 TABLE 13 Internal Discharge capacity resistance Electrolyte Solvent Additive retention (%) ratio Example 18 LiPF.sub.6 EC/DEC Compound 25 91 1.36 1.0 mol/L (30/70) vol % 0.5% by mass Example 19 LiPF.sub.6 EC/DEC Compound 25 96 1.25 1.0 mol/L (30/70) vol % 1.0% by mass Example 20 LiPF.sub.6 EC/DEC Compound 26 97 1.22 1.0 mol/L (30/70) vol % 1.0% by mass Example 21 LiPF.sub.6 EC/DEC Compound 27 96 1.26 1.0 mol/L (30/70) vol % 1.0% by mass Example 22 LiPF.sub.6 EC/DEC Compound 28 97 1.24 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC None 74 1.83 Example 9 1.0 mol/L (30/70) vol % Comparative LiPF.sub.6 EC/DEC PS 77 1.68 Example 10 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 83 1.69 Example 11 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 84 1.53 Example 12 1.0 mol/L (30/70) vol % 2.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 81 1.66 Example 13 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 83 1.67 Example 14 1.0 mol/L (30/70) vol % 2.0% by mass

(184) Table 13 shows that the cylindrical secondary batteries each using a non-aqueous electrolyte solution containing a phosphorus-containing sulfonic acid amide compound prepared in each of the examples have a higher discharge capacity retention in a cycle test than the cylindrical secondary batteries each using a non-aqueous electrolyte solution of each of the comparative examples. Therefore, in cells such as non-aqueous electrolyte solution secondary cells, the non-aqueous electrolyte solutions each containing an additive for a non-aqueous electrolyte solution formed from a phosphorus-containing sulfonic acid amide compound obtained in each of the examples provide an SEI with higher stability to charge/discharge cycle on the surface of an electrode of the cells than the non-aqueous electrolyte solutions of the comparative examples. Further, the non-aqueous electrolyte solutions each containing a phosphorus-containing sulfonic acid amide compound of each of the examples can keep an internal resistance ratio lower than the non-aqueous electrolyte solutions of the comparative examples, and suppress an increase in internal resistance during a cycle test.

EXAMPLE 23

Preparation of methanedisulfonic acid bispyrrolidine (compound 29)

(185) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with pyrrolidine (7.3 g) (0.103 mol) and 1,2-dimethoxyethane (100 g), and a solution of methanedisulfonyl chloride (10.0 g) (0.047 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (11.4 g) (0.112 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(186) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bispyrrolidine (6.0 g) (0.021 mol). The yield of the methanedisulfonic acid bispyrrolidine was 45.2% based on the amount of the methanedisulfonyl chloride.

(187) The resulting methanedisulfonic acid bispyrrolidine was identified by its properties described below.

(188) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 1.58 ppm (dt, 8H), 2.80 ppm (t, 8H), 5.55 ppm (s, 2H)

(189) (Preparation of Non-Aqueous Electrolyte Solution)

(190) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 29 shown in Table 14 as an additive for a non-aqueous electrolyte solution was added to the solution in an amount of 0.5% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 24

(191) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that the amount of the compound 29 was 1.0% by mass in Preparation of non-aqueous electrolyte solution.

EXAMPLE 25

Preparation of methanedisulfonic acid bispiperidine (compound 30)

(192) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with piperidine (8.8 g) (0.103 mol) and 1,2-dimethoxyethane (100 g), and a solution of methanedisulfonyl chloride (10.0 g) (0.047 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (11.4 g) (0.112 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(193) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bispiperidine (4.5 g) (0.014 mol). The yield of the methanedisulfonic acid bispiperidine was 30.8% based on the amount of the methanedisulfonyl chloride.

(194) The resulting methanedisulfonic acid bispiperidine was identified by its properties described below.

(195) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 1.47 ppm (dt, 8H), 1.51 ppm (dt, 4H), 2.66 ppm (t, 8H), 5.73 ppm (s, 2H)

(196) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that the compound 30 was used in an amount of 1.0% by mass instead of the compound 29 in Preparation of non-aqueous electrolyte solution.

EXAMPLE 26

Preparation of methanedisulfonic acid bismorpholine (compound 31)

(197) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with morpholine (9.0 g) (0.103 mol) and 1,2-dimethoxyethane (100 g), and a solution of methanedisulfonyl chloride (10.0 g) (0.047 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (11.4 g) (0.112 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(198) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bismorpholine (8.6 g) (0.027 mol). The yield of the methanedisulfonic acid bismorpholine was 58.2% based on the amount of the methanedisulfonyl chloride.

(199) The resulting methanedisulfonic acid bismorpholine was identified by its properties described below.

(200) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 3.25 (t, 8H), 3.64 (t, 8H), 5.12 (s, 2H)

(201) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that the compound 31 was used in an amount of 1.0% by mass instead of the compound 29 in Preparation non-aqueous electrolyte solution.

EXAMPLE 27

Preparation of methanedisulfonic acid bisthiomorpholine (compound 32)

(202) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with thiomorpholine (10.6 g) (0.103 mol) and 1,2-dimethoxyethane (100 g), and a solution of methanedisulfonyl chloride (10.0 g) (0.047 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (11.4 g) (0.112 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(203) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bisthiomorpholine (5.3 g) (0.015 mol). The yield of the methanedisulfonic acid bisthiomorpholine was 32.5% based on the amount of the methanedisulfonyl chloride.

(204) The resulting methanedisulfonic acid bisthiomorpholine was identified by its properties described below.

(205) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 3.33 (t, 8H), 3.66 (t, 8H), 5.13 (s, 2H)

(206) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that the compound 32 was used in an amount of 1.0% by mass instead of the compound 29 in (Preparation of non-aqueous electrolyte solution).

EXAMPLE 28

Preparation of methanedisulfonic acid bis(1-methylpiperazine) (compound 33)

(207) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 1-methylpiperazine (10.3 g) (0.103 mol) and 1,2-dimethoxyethane (100 g), a solution of methanedisulfonyl chloride (10.0 g) (0.047 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (11.4 g) (0.113 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(208) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(1-methylpiperazine) (6.7 g) (0.020 mol). The yield of the methanedisulfonic acid bis(1-methylpiperazine) was 41.9% based on the amount of the methanedisulfonyl chloride.

(209) The resulting methanedisulfonic acid bis(1-methylpiperazine) was identified by its properties described below.

(210) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 3.32 (s, 6H), 3.55 (t, 8H), 3.67 (t, 8H), 5.11 (s, 2H)

(211) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that the compound 33 was used in an amount of 1.0% by mass instead of the compound 29 in (Preparation of non-aqueous electrolyte solution).

EXAMPLE 29

Preparation of 1,2-ethanedisulfonic acid bismorpholine (compound 34)

(212) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with morpholine (8.4 g) (0.097 mol) and 1,2-dimethoxyethane (100 g), a solution of 1,2-ethane disulfonyl chloride (10.0 g) (0.044 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Subsequently, while maintaining the temperature at 0 C., a solution of triethylamine (10.7 g) (0.106 mol) dissolved in 1,2-dimethoxyethane (10 g) was added dropwise over 1 hour, followed by stirring over night at the same temperature.

(213) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give 1,2-ethanedisulfonic acid bismorpholine (7.6 g) (0.023 mol). The yield of the 1,2-ethanedisulfonic acid bismorpholine was 52.6% based on the amount of the 1,2-ethane disulfonyl chloride.

(214) The resulting 1,2-ethanedisulfonic acid bismorpholine was identified by its properties described below.

(215) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 3.34 (t, 8H), 3.65 (t, 8H), 5.02 (s, 4H)

(216) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that the compound 34 was used in an amount of 1.0% by mass instead of the compound 29 in (Preparation of non-aqueous electrolyte solution).

COMPARATIVE EXAMPLE 15

(217) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that the compound 29 was not used in (Preparation of non-aqueous electrolyte solution) in Example 23.

COMPARATIVE EXAMPLE 16

(218) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that 1,3-propane sultone (PS) was used in an amount of 1.0% by mass instead of the compound 29 in (Preparation of non-aqueous electrolyte solution) in Example 23.

COMPARATIVE EXAMPLE 17

(219) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that vinylene carbonate (VC) was used in an amount of 1.0% by mass instead of the compound 29 in (Preparation of non-aqueous electrolyte solution) in Example 23.

COMPARATIVE EXAMPLE 18

(220) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 17 except that the amount of the vinylene carbonate (VC) was 2.0% by mass.

COMPARATIVE EXAMPLE 19

(221) A non-aqueous electrolyte solution was prepared in the same manner as in Example 23 except that fluoroethylene carbonate (FEC) was used in an amount of 1.0% by mass instead of the compound 29 in (Preparation of non-aqueous electrolyte solution) in Example 23.

COMPARATIVE EXAMPLE 20

(222) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 19 except that the amount of the fluoroethylene carbonate (FEC) was 2.0% by mass.

(223) <Evaluation>

(224) The compounds 29 to 34 prepared in the examples and the non-aqueous electrolyte solutions prepared in the examples and comparative examples were evaluated as follows.

(225) (LUMO Energy, Standard Enthalpy of Formation (H), Enthalpy Change (H) with Hydrolysis Reaction)

(226) The LUMO (lowest unoccupied molecular orbital) energies of the resulting compounds 29 to 34 prepared in the examples were derived using the Gaussian 03 software. The results are shown in Table 14.

(227) Further, the standard enthalpies of formation (H) of the compounds 29 to 34 prepared in the examples were derived using the MOPAC 97 software. The results are shown in Table 14.

(228) Further, the enthalpy changes (H) with hydrolysis reaction of the compounds 29 to 34 prepared in the examples were derived using the Gaussian 03 software. The results are shown in Table 14.

(229) TABLE-US-00014 TABLE 14 LUMO H H energy (kcal/ (kcal/ Structure (eV) mol) mol) Compound 29 0.29 139.9 3.2 Compound 30 0.27 158.5 2.6 Compound 31 0.15 213.5 3.0 Compound 32 0.21 125.8 3.5 Compound 33 0.32 155.8 1.9 Compound 34 0 0.36 211.0 1.8

(230) Table 14 shows that the disulfonic acid amide compounds (compounds 29 to 34) represented by the formula (17) have a LUMO energy of about 0.15 eV to about 0.36 eV, and these disulfonic acid amide compounds according to the additive for a non-aqueous electrolyte solution of the present invention have a lower LUMO energy than solvents of commonly used non-aqueous electrolyte solutions (for example, cyclic carbonate and chain carbonate: LUMO energy of about 1.2 eV). Therefore, in cases where the compounds 29 to 34 are used as an additive for a non-aqueous electrolyte solution for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the compounds 29 to 34 are electrochemically reduced prior to electrochemical reduction of solvents of non-aqueous electrolyte solutions, and an SEI is formed on an electrode, whereby decomposition of solvent molecules in an electrolyte solution can be suppressed. As a result, a high resistant film produced by decomposition of the solvent is less likely to be formed on an electrode to probably improve cell performance.

(231) Table 14 shows that the disulfonic acid amide compounds (compounds 29 to 34) represented by the formula (17) have a standard enthalpy of formation (H) of about 125.8 kcal/mol to about 213.5 kcal/mol. That is, the compounds 29 to 34 according to the present invention have excellent storage stability in a non-aqueous electrolyte solution. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(232) Further, Table 14 shows that the disulfonic acid amide compounds (compounds 29 to 34) represented by the formula (17) have an enthalpy change (H) with hydrolysis reaction of about 1.8 kcal/mol to about 3.5 kcal/mol. That is, the compounds 29 to 34 according to the present invention are also stable to moisture. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(233) Thus, the disulfonic acid amide compounds represented by the formula (17) according to the additive for a non-aqueous electrolyte solution of the present invention have a sufficiently low LUMO energy, excellent storage stability when contained in a non-aqueous electrolyte solution as an additive for a non-aqueous electrolyte solution, and excellent stability to moisture. This shows that such compounds are effective as a novel additive for a non-aqueous electrolyte solution capable of forming a stable SEI on an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(234) (Evaluation of Stability)

(235) The compounds 29 to 34 obtained in the examples and commonly used fluoroethylene carbonate (FEC) were subjected to a storage test for 90 days under constant temperature and humidity conditions of a temperature of 402 C. and humidity of 755%. The degradability of each compound was measured and evaluated with .sup.1H-nuclear magnetic resonance spectrum (.sup.1H-NMR). Table 15 shows the results. Good: There is no change in peaks in .sup.1H-NMR before and after storage. Poor: There is a change in peaks in .sup.1H-NMR before and after storage.

(236) TABLE-US-00015 TABLE 15 Additive Stability Compound 29 Good Compound 30 Good Compound 31 Good Compound 32 Good Compound 33 Good Compound 34 Good FEC Poor
(Preparation of Cell)

(237) LiMn.sub.2O.sub.4 as a cathode active material and a carbon black as a conductivity imparting agent were dry mixed, and the mixture was uniformly dispersed in N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride (PVDF) was dissolved as a binder to prepare a slurry. The resulting slurry was applied to an aluminum foil (square, thickness of 20 m) that is to be a cathode current collector, and the NMP was dried off to prepare a cathode sheet. The resulting cathode sheet had a solid mass ratio of cathode active material:conductivity imparting agent:PVDF=80:10:10.

(238) A commercially available graphite-coated electrode sheet (produced by Hohsen Corp.) was used as an anode sheet.

(239) A cylindrical secondary battery was prepared in such a way that an anode sheet and a cathode sheet were laminated and a polyethylene separator was disposed between the sheets in a non-aqueous electrolyte solution prepared in each of the examples and comparative examples.

(240) (Measurement of Discharge Capacity Retention and Internal Resistance Ratio)

(241) The resulting cylindrical secondary batteries were subjected to a charge/discharge cycle test under the conditions of a temperature of 25 C., a charging rate of 0.3 C, a discharging rate of 0.3 C, a charge termination voltage of 4.2 V, and a discharge termination voltage of 2.5 V. Table 16 shows discharge capacity retention (%) and internal resistance ratio after 200 cycles.

(242) The discharge capacity retention (%) after 200 cycles was determined by dividing the discharge capacity (mAh) after 200 cycles of the cycle test by the discharge capacity (mAh) after 10 cycles of the cycle test and multiplying the resulting value by 100. Further, the internal resistance ratio after 200 cycles was expressed as a value of the resistance after 200 cycles of the cycle test relative to a value of the resistance before the cycle test taken as 1.

(243) TABLE-US-00016 TABLE 16 Internal Discharge capacity resistance Electrolyte Solvent Additive retention (%) ratio Example 23 LiPF.sub.6 EC/DEC Compound 29 93 1.24 1.0 mol/L (30/70) vol % 0.5% by mass Example 24 LiPF.sub.6 EC/DEC Compound 29 94 1.18 1.0 mol/L (30/70) vol % 1.0% by mass Example 25 LiPF.sub.6 EC/DEC Compound 30 95 1.13 1.0 mol/L (30/70) vol % 1.0% by mass Example 26 LiPF.sub.6 EC/DEC Compound 31 92 1.15 1.0 mol/L (30/70) vol % 1.0% by mass Example 27 LiPF.sub.6 EC/DEC Compound 32 93 1.12 1.0 mol/L (30/70) vol % 1.0% by mass Example 28 LiPF.sub.6 EC/DEC Compound 33 92 1.15 1.0 mol/L (30/70) vol % 1.0% by mass Example 29 LiPF.sub.6 EC/DEC Compound 34 91 1.17 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC None 74 1.83 Example 15 1.0 mol/L (30/70) vol % Comparative LiPF.sub.6 EC/DEC PS 77 1.68 Example 16 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 83 1.69 Example 17 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 84 1.53 Example 18 1.0 mol/L (30/70) vol % 2.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 81 1.66 Example 19 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 83 1.67 Example 20 1.0 mol/L (30/70) vol % 2.0% by mass

(244) Table 16 shows that the cylindrical secondary batteries each using a non-aqueous electrolyte solution of each of the examples have a higher discharge capacity retention in a cycle test than the cylindrical secondary batteries each using a non-aqueous electrolyte solution of each of the comparative examples. Therefore, in cells such as non-aqueous electrolyte solution secondary cells, the non-aqueous electrolyte solutions of the examples provide an SEI with higher stability to charge/discharge cycle on the surface of an electrode of the cells than the non-aqueous electrolyte solutions of the comparative examples.

(245) Further, the non-aqueous electrolyte solutions of the examples have smaller internal resistance than the non-aqueous electrolyte solutions of the comparative examples, and therefore suppress an increase in internal resistance during a cycle test.

PRODUCTION EXAMPLE 1

(246) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 2,2,2-trifluoroethanol (9.4 g) (0.094 mol) and 1,2-dimethoxyethane (40.0 g), and methanedisulfonyl chloride (10.0 g) (0.047 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Triethylamine (9.5 g) (0.094 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 1 hour while maintaining the temperature at 0 C., followed by stirring over night at the same temperature.

(247) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(2,2,2-trifluoroethyl ester) (12.0 g) (0.035 mol). The yield of the methanedisulfonic acid bis(2,2,2-trifluoroethyl ester) was 75.2% based on the amount of the methanedisulfonyl chloride. The resulting methanedisulfonic acid bis(2,2,2-trifluoroethyl ester) was identified by its properties described below.

(248) .sup.1H-nuclear magnetic resonance spectrum (solvent: CD.sub.3CN) (ppm): 5.39 (s, 2H), 4.83 (dd, 4H) LC/MS (m/z [M-H]+): 339

PRODUCTION EXAMPLE 2

(249) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 1,1,1-trifluoro-2-propanol (10.7 g) (0.094 mol) and 1,2-dimethoxyethane (40.0 g), and methanedisulfonyl chloride (10.0 g) (0.047 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Triethylamine (9.5 g) (0.094 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 1 hour while maintaining the temperature at 0 C., followed by stirring over night at the same temperature.

(250) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(2,2,2-trifluoro-1-methyl ethyl ester) (13.4 g) (0.036 mol). The yield of the methanedisulfonic acid bis(2,2,2-trifluoro-1-methyl ethyl ester) was 77.4% based on the amount of the methanedisulfonyl chloride. The resulting methanedisulfonic acid bis(2,2,2-trifluoro-1-methyl ethyl ester) was identified by its properties described below.

(251) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 5.78 (q, 2H), 5.53 (s, 2H), 1.49 (d, 6H) LC/MS (m/z [M-H]+): 367

PRODUCTION EXAMPLE 3

(252) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 3,3,3-trifluoro-1-propanol (10.7 g) (0.094 mol) and 1,2-dimethoxyethane (40.0 g), and methanedisulfonyl chloride (10.0 g) (0.047 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Triethylamine (9.5 g) (0.094 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 1 hour while maintaining the temperature at 0 C., followed by stirring over night at the same temperature.

(253) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(3,3,3-trifluoro propyl ester) (12.8 g) (0.035 mol). The yield of the methanedisulfonic acid bis(3,3,3-trifluoro propyl ester) was 74.4% based on the amount of the methanedisulfonyl chloride. The resulting methanedisulfonic acid bis(3,3,3-trifluoro propyl ester) was identified by its properties described below.

(254) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 5.53 (s, 2H), 3.53 (d, 4H), 2.00 (dd, 4H) LC/MS (m/z [M-H]+): 367

PRODUCTION EXAMPLE 4

(255) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 4,4,4-trifluoro-1-butanol (12.0 g) (0.094 mol) and 1,2-dimethoxyethane (40.0 g), and methanedisulfonyl chloride (10.0 g) (0.047 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Triethylamine (9.5 g) (0.094 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 1 hour while maintaining the temperature at 0 C., followed by stirring over night at the same temperature.

(256) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid bis(4,4,4-trifluoro butyl ester) (16.2 g) (0.041 mol). The yield of the methanedisulfonic acid bis(4,4,4-trifluoro butyl ester) was 87.2% based on the amount of the methanedisulfonyl chloride. The resulting methanedisulfonic acid bis(4,4,4-trifluoro butyl ester) was identified by its properties described below.

(257) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 5.52 (s, 2H), 3.55 (d, 4H), 1.81 (dd, 4H), 1.48 (dd, 4H)

(258) LC/MS (m/z [M-H]+): 395

PRODUCTION EXAMPLE 5

(259) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 2,2,2-trifluoroethanol (4.7 g) (0.047 mol) and 1,2-dimethoxyethane (20.0 g), and methanedisulfonyl chloride (10.0 g) (0.047 mol) mixed with 1,2-dimethoxyethane (10.0 g) was added dropwise over 20 minutes while maintaining the temperature at 0 C. Triethylamine (4.8 g) (0.047 mol) mixed with 1,2-dimethoxyethane (5.0 g) was added dropwise over 1 hour while maintaining the temperature at 0 C., followed by stirring for 6 hours at the same temperature. Further, phenol (4.4 g) (0.047 mol) and 1,2-dimethoxyethane (20.0 g) were added dropwise over 20 minutes at 0 C. Triethylamine (4.8 g) (0.047 mol) mixed with 1,2-dimethoxyethane (5.0 g) was added dropwise over 1 hour while maintaining the temperature at 0 C., followed by stirring over night at the same temperature.

(260) After the completion of the reaction, the reaction solution was filtered, and toluene (100.0 g) and water (50.0 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and part of the solvent was removed from the organic phase by reduced pressure distillation at 25 C., whereby crystals were obtained. The crystals were filtered and dried to give methanedisulfonic acid-2,2,2-trifluoroethyl ester phenyl ester (12.7 g) (0.038 mol). The yield of the methanedisulfonic acid-2,2,2-trifluoroethyl ester phenyl ester was 80.8% based on the amount of the methanedisulfonyl chloride.

(261) The resulting methanedisulfonic acid-2,2,2-trifluoroethyl ester phenyl ester was identified by its properties described below.

(262) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.33 (d, 2H), 7.25 (s, 1H), 7.21 (m, 2H), 5.53 (s, 2H), 4.05 (d, 2H)

(263) LC/MS (m/z [M-H]+): 333

EXAMPLE 30

Preparation of methanedisulfonic acid-2,2-difluoro vinyl ester-2,2,2-trifluoroethyl ester (compound 35: halogen-containing disulfonic acid ester compound represented by the formula (21))

(264) A 500-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(2,2,2-trifluoroethyl ester) (12.0 g) (0.035 mol) prepared in the same manner as in Production Example 1 and tetrahydrofuran (175.0 mL), and the contents were cooled to 78 C. A 2.6-mol/L n-butyllithium-hexane solution (56.0 mL) (0.15 mol) was added dropwise over 1 hour while maintaining the temperature at 78 C., followed by stirring for 6 hours at the same temperature. After the completion of the reaction, to the reaction solution were added dropwise a tetrahydrofuran-water mixed solution (volume ratio of 1:1) (116.7 mL) and a saturated aqueous ammonium chloride solution (140.0 mL). Next, extraction was repeated three times using ethyl acetate (116.7 mL). Part of the solvent was removed from the resulting organic phase by reduced pressure distillation at 25 C. to give a concentrate. The concentrate was purified by column chromatography (an ethyl acetate-heptane mixed solvent was used as a mobile phase) to give methanedisulfonic acid-2,2-difluoro vinyl ester-2,2,2-trifluoroethyl ester (6.5 g) (0.020 mol). The yield of the methanedisulfonic acid-2,2-difluoro vinyl ester-2,2,2-trifluoroethyl ester was 57.1% based on the amount of the methanedisulfonic acid bis(2,2,2-trifluoroethyl ester).

(265) The resulting methanedisulfonic acid-2,2-difluoro vinyl ester-2,2,2-trifluoroethyl ester was identified by its properties described below.

(266) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 6.36 (dd, 1H), 4.93 (s, 2H), 4.72 (dd, 2H) LC/MS (m/z [M-H]+): 319

EXAMPLE 31

Preparation of methanedisulfonic acid bis(2,2-difluoro vinyl ester) (compound 36: halogen-containing disulfonic acid ester compound represented by the formula (23))

(267) A 500-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(2,2,2-trifluoroethyl ester) (12.0 g) (0.035 mol) prepared in the same manner as in Production Example 1 and tetrahydrofuran (175.0 mL), and the contents were cooled to 78 C. A 2.6-mol/L n-butyllithium-hexane solution (112.0 mL) (0.30 mol) was added dropwise over 1 hour while maintaining the temperature at 78 C., followed by stirring at the same temperature for 6 hours. The contents were heated to 20 C. and stirred at the same temperature for 2 hours. After the completion of the reaction, to the reaction solution were added dropwise a tetrahydrofuran-water mixed solution (volume ratio of 1:1) (116.7 mL) and a saturated aqueous ammonium chloride solution (140.0 mL). Subsequently, extraction was repeated three times using ethyl acetate (116.7 mL). Part of the solvent was removed from the resulting organic phase by reduced pressure distillation at 25 C. to give a concentrate. The concentrate was purified by column chromatography (an ethyl acetate-heptane mixed solvent was used as a mobile phase) to give methanedisulfonic acid bis(2,2-difluoro vinyl ester) (7.0 g) (0.023 mol). The yield of the methanedisulfonic acid bis(2,2-difluoro vinyl ester) was 66.4% based on the amount of the methanedisulfonic acid bis(2,2,2-trifluoroethyl ester).

(268) The resulting methanedisulfonic acid bis(2,2-difluoro vinyl ester) was identified by its properties described below.

(269) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 6.38 (dd, 2H), 4.92 (s, 2H) LC/MS (m/z [M-H]+): 299

EXAMPLE 32

Preparation of methanedisulfonic acid bis(2,2-difluoro-1-methyl vinyl ester) (compound 37)

(270) A 500-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(2,2,2-trifluoro-1-methyl ethyl ester) (12.9 g) (0.035 mol) prepared in the same manner as in Production Example 2 and tetrahydrofuran (175.0 mL), and the contents were cooled to 78 C. A 2.6-mol/L n-butyllithium-hexane solution (112.0 mL) (0.30 mol) was added dropwise over 1 hour while maintaining the temperature at 78 C., followed by stirring at the same temperature for 6 hours. The contents were heated to 20 C. and stirred at the same temperature for 2 hours. After the completion of the reaction, to the reaction solution were added dropwise a tetrahydrofuran-water mixed solution (volume ratio of 1:1) (116.7 mL) and a saturated aqueous ammonium chloride solution (140.0 mL). Next, extraction was repeated three times using ethyl acetate (116.7 mL). Part of the solvent was removed from the resulting organic phase by reduced pressure distillation at 25 C. to give a concentrate. The concentrate was purified by column chromatography (an ethyl acetate-heptane mixed solvent was used as a mobile phase) to give methanedisulfonic acid bis(2,2-difluoro-1-methyl vinyl ester) (8.5 g) (0.026 mol). The yield of the methanedisulfonic acid bis(2,2-difluoro-1-methyl vinyl ester) was 74.3% based on the amount of the methanedisulfonic acid bis(2,2,2-trifluoro-1-methyl ethyl ester).

(271) The resulting methanedisulfonic acid bis(2,2-difluoro-1-methyl vinyl ester) was identified by its properties described below.

(272) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 5.53 (s, 2H), 1.71 (s, 6H) LC/MS (m/z [M-H]+): 327

EXAMPLE 33

Preparation of methanedisulfonic acid bis(3,3-difluoro-2-propenyl ester) (compound 38)

(273) A 500-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(3,3,3-trifluoro propyl ester) (12.8 g) (0.035 mol) prepared in the same manner as in Production Example 3 and tetrahydrofuran (175.0 mL), and the contents were cooled to 78 C. A 2.6-mol/L n-butyllithium-hexane solution (112.0 mL) (0.30 mol) was added dropwise over 1 hour while maintaining the temperature at 78 C., followed by stirring at the same temperature for 6 hours. The contents were heated to 20 C. and stirred at the same temperature for 2 hours. After the completion of the reaction, to the reaction solution were added dropwise a tetrahydrofuran-water mixed solution (volume ratio of 1:1) (116.7 mL) and a saturated aqueous ammonium chloride solution (140.0 mL). Then, extraction was repeated three times using ethyl acetate (116.7 mL). Part of the solvent was removed from the resulting organic phase by reduced pressure distillation at 25 C. to give a concentrate. The concentrate was purified by column chromatography (an ethyl acetate-heptane mixed solvent was used as a mobile phase) to give methanedisulfonic acid bis(3,3-difluoro-2-propenyl ester (7.0 g) (0.021 mol). The yield of the methanedisulfonic acid bis(3,3-difluoro-2-propenyl ester was 60.0% based on the amount of the methanedisulfonic acid bis(3,3,3-trifluoro propyl ester).

(274) The resulting methanedisulfonic acid bis(3,3-difluoro-2-propenyl ester) was identified by its properties described below.

(275) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 5.53 (s, 2H), 4.47 (dd, 2H), 4.20 (d, 4H) LC/MS (m/z [M-H]+): 327

EXAMPLE 34

Preparation of methanedisulfonic acid bis(4,4-difluoro-3-butenyl ester) (compound 39)

(276) A 500-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid bis(4,4,4-trifluoro butyl ester) (13.9 g) (0.035 mol) prepared in the same manner as in Production Example 4 and tetrahydrofuran (175.0 mL), and the contents were cooled to 78 C. A 2.6-mol/L n-butyllithium-hexane solution (112.0 mL) (0.30 mol) was added dropwise over 1 hour while maintaining the temperature at 78 C., followed by stirring at the same temperature for 6 hours. The contents were heated to 20 C. and stirred at the same temperature for 2 hours. After the completion of the reaction, to the reaction solution were added dropwise a tetrahydrofuran-water mixed solution (volume ratio of 1:1) (116.7 mL) and a saturated aqueous ammonium chloride solution (140.0 mL). Subsequently, extraction was repeated three times using ethyl acetate (116.7 mL). Part of the solvent was removed from the resulting organic phase by reduced pressure distillation at 25 C. to give a concentrate. The concentrate was purified by column chromatography (an ethyl acetate-heptane mixed solvent was used as a mobile phase) to give methanedisulfonic acid bis(4,4-difluoro-3-butenyl ester) (6.8 g) (0.019 mol). The yield of the methanedisulfonic acid bis(4,4-difluoro-3-butenyl ester) was 54.3% based on the amount of the methanedisulfonic acid bis(4,4,4-trifluoro butyl ester).

(277) The resulting methanedisulfonic acid bis(4,4-difluoro-3-butenyl ester) was identified by its properties described below.

(278) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 5.52 (s, 2H), 4.28 (dd, 2H), 3.57 (d, 4H), 2.15 (d, 4H)

(279) LC/MS (m/z [M-H]+): 355

EXAMPLE 35

Preparation of methanedisulfonic acid-2,2-difluoro vinyl ester phenyl ester) (compound 40)

(280) A 500-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with methanedisulfonic acid-2,2,2-trifluoroethyl ester phenyl ester (11.7 g) (0.035 mol) prepared in the same manner as in Production Example 5 and tetrahydrofuran (175.0 mL), and the contents were cooled to 78 C. A 2.6-mol/L n-butyllithium-hexane solution 56.0 mL (0.15 mol) was added dropwise over 1 hour while maintaining the temperature at 78 C., followed by stirring for 6 hours at the same temperature. After the completion of the reaction, to the reaction solution were added dropwise a tetrahydrofuran-water mixed solution (volume ratio of 1:1) (116.7 mL) and a saturated aqueous ammonium chloride solution (140.0 mL). Subsequently, extraction was repeated three times using ethyl acetate (116.7 mL). Part of the solvent was removed from the resulting organic phase by reduced pressure distillation at 25 C. to give a concentrate. The resulting concentrate was purified by column chromatography (an ethyl acetate-heptane mixed solvent was used as a mobile phase) to give methanedisulfonic acid-2,2-difluoro vinyl ester phenyl ester (6.0 g) (0.019 mol). The yield of the methanedisulfonic acid-2,2-difluoro vinyl ester phenyl ester was 54.2% based on the amount of the methanedisulfonic acid-2,2,2-trifluoroethyl ester phenyl ester.

(281) The resulting methanedisulfonic acid-2,2-difluoro vinyl ester phenyl ester was identified by its properties described below.

(282) .sup.1H-nuclear magnetic resonance spectrum (solvent: CDCl.sub.3) (ppm): 7.34 (d, 2H), 7.25 (s, 1H), 7.20 (m, 2H), 5.52 (s, 2H), 3.80 (d, 1H)

(283) LC/MS (m/z [M-H]+): 313

COMPARATIVE EXAMPLE 21

Preparation of methanedisulfonic acid bis(2,2,2-trifluoroethyl ester) (compound 41)

(284) Methanedisulfonic acid bis(2,2,2-trifluoroethyl ester) (12.0 g) (0.035 mol) was prepared in the same manner as in Production Example 1.

COMPARATIVE EXAMPLE 22

Preparation of methanedisulfonic acid bis(2,2,2-trichloroethyl ester) (compound 42)

(285) Methanedisulfonic acid bis(2,2,2-trichloroethyl ester) (13.0 g) (0.029 mol) was prepared in the same manner as in Production Example 1 except that 2,2,2-trichloroethanol (14.0 g) (0.094 mol) was used instead of 2,2,2-trifluoroethanol (9.4 g) (0.094 mol). The yield of the methanedisulfonic acid bis(2,2,2-trichloroethyl ester) was 63% based on the amount of the methanedisulfonyl chloride.

COMPARATIVE EXAMPLE 23

Preparation of methanedisulfonic acid bis(3,3,3-trifluoro propyl ester) (compound 43)

(286) Methanedisulfonic acid bis(3,3,3-trifluoro propyl ester (10.0 g) (0.027 mol) was prepared in the same manner as in Production Example 3.

(287) <Evaluation>

(288) (LUMO energy, standard enthalpy of formation (H), enthalpy change (H) with hydrolysis reaction)

(289) The LUMO (lowest unoccupied molecular orbital) energies of the compounds 35 to 43 prepared in the examples and comparative examples were derived using the Gaussian 03 software. The results are shown in Table 17.

(290) Further, the standard enthalpies of formation (H) of the compounds 35 to 43 prepared in the examples and comparative examples were derived using the MOPAC 97 software. The results are shown in Table 17.

(291) Further, the enthalpy changes (H) with hydrolysis reaction of the compounds 35 to 43 in the examples and comparative examples were derived using the Gaussian 03 software. The results are shown in Table 17.

(292) TABLE-US-00017 TABLE 17 LUMO energy H H Structure (eV) (kcal/mol) (kcal/mol) Compound 35 1.00 199.1 4.2 Compound 36 1.17 211.6 4.0 Compound 37 1.05 209.2 3.6 Compound 38 1.01 189.3 3.8 Compound 39 1.12 190.6 3.8 Compound 40 1.08 215.3 3.4 Compound 41 0.37 246.0 4.1 Compound 42 0.21 258.5 4.3 Compound 43 0.25 252.7 5.7

(293) Table 17 shows that the halogen-containing disulfonic acid ester compounds (compounds 35 to 40) represented by the formula (19) have a negative LUMO energy of about 1.00 eV to about 1.17 eV, and these halogen-containing disulfonic acid ester compounds according to the additive for a non-aqueous electrolyte solution of the present invention have a low LUMO energy. Therefore, in cases where the compounds 35 to 40 are used as an additive for a non-aqueous electrolyte solution for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the compounds 35 to 40 are electrochemically reduced prior to electrochemical reduction of solvents of non-aqueous electrolyte solutions (for example, cyclic carbonate and chain carbonate: LUMO energy of about 1.2 eV), and an SEI is formed on an electrode, whereby decomposition of solvent molecules in an electrolyte solution can be suppressed. As a result, a high resistant film produced by decomposition of the solvent is less likely to be formed on an electrode to probably improve cell performance.

(294) On the other hand, Table 17 shows that the halogen-containing disulfonic acid ester compounds (compounds 41 to 43) other than the halogen-containing disulfonic acid ester compounds represented by the formula (19) have a relatively high LUMO energy of about 0.37 eV to about 0.21 eV. That is, the compounds 41 to 43 are relatively stable to electrochemical reduction and are less likely to form an SEI on an electrode.

(295) Table 17 shows that the halogen-containing disulfonic acid ester compounds (compounds 35 to 40) represented by the formula (19) have a standard enthalpy of formation (H) of about 189.3 kcal/mol to about 215.3 kcal/mol. That is, the compounds 35 to 40 according to the present invention have excellent storage stability in a non-aqueous electrolyte solution. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on the surface of an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(296) Further, Table 17 shows halogen-containing disulfonic acid ester compounds (compounds 35 to 40) represented by the formula (19) have an enthalpy change (H) with hydrolysis reaction of about 3.4 kcal/mol to about 4.2 kcal/mol. That is, the compounds 35 to 40 according to the present invention are also stable to moisture. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(297) Thus, the halogen-containing disulfonic acid ester compounds represented by the formula (19) according to the additive for a non-aqueous electrolyte solution of the present invention have a sufficiently low LUMO energy, excellent storage stability when contained in a non-aqueous electrolyte solution as an additive for a non-aqueous electrolyte solution, and excellent stability to moisture. This shows that such compounds are effective as a novel additive for a non-aqueous electrolyte solution capable of forming a stable SEI on an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(298) (Measurement of LSV (linear sweep voltammetry))

(299) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. A halogen-containing disulfonic acid ester compound obtained in each of the examples and comparative examples was added as an additive for a non-aqueous electrolyte solution in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Polarization was measured in a potential scanning rate of 5 mV/sec using the resulting non-aqueous electrolyte solution, a disk electrode made from glassy carbon as an electrode, and platinum as a counter electrode. A reduction starting voltage was calculated using a silver electrode as a reference electrode, in which the potential with respect to the reference electrode when 100 A of current flows was defined as oxidation potential and the potential with respect to the reference electrode when 100 A of current flows was defined as reduction potential. Further, as Reference Example 3, a reduction starting voltage was similarly calculated using a non-aqueous electrolyte solution prepared without adding an additive for a non-aqueous electrolyte solution. Table 18 shows the results.

(300) TABLE-US-00018 TABLE 18 LSV Reduction starting Electrolyte Solvent Additive voltage (V) Example 30 LiPF.sub.6 EC/DEC Compound 35 2.8 1.0 mol/L (30/70) vol % 1.0% by mass Example 31 LiPF.sub.6 EC/DEC Compound 36 2.7 1.0 mol/L (30/70) vol % 1.0% by mass Example 32 LiPF.sub.6 EC/DEC Compound 37 2.7 1.0 mol/L (30/70) vol % 1.0% by mass Example 33 LiPF.sub.6 EC/DEC Compound 38 2.6 1.0 mol/L (30/70) vol % 1.0% by mass Example 34 LiPF.sub.6 EC/DEC Compound 39 2.7 1.0 mol/L (30/70) vol % 1.0% by mass Example 35 LiPF.sub.6 EC/DEC Compound 40 2.5 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 41 3.3 Example 21 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 42 3.6 Example 22 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 43 3.4 Example 23 1.0 mol/L (30/70) vol % 1.0% by mass Reference LiPF.sub.6 EC/DEC None 3.6 Example 3 1.0 mol/L (30/70)vol %

(301) Table 18 shows that the non-aqueous electrolyte solutions each containing a halogen-containing disulfonic acid ester compound obtained in each of the examples have a higher reduction starting voltage than the non-aqueous electrolyte solution of Reference Example 3 and the non-aqueous electrolyte solutions each containing a compound prepared in each of the comparative examples. Therefore, in cases where a non-aqueous electrolyte solution containing an additive for a non-aqueous electrolyte solution made from a halogen-containing disulfonic acid ester compound prepared in each of the examples is used for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the halogen-containing disulfonic acid ester compounds according to the present invention are electrochemically reduced prior to electrochemical reduction of the non-aqueous electrolyte solution of Reference Example 3 and the non-aqueous electrolyte solutions containing the respective compound 41 to 43 prepared in the comparative examples. Further, a stable SEI is easily formed on the surface of an electrode of cells such as non-aqueous electrolyte solution secondary cells.

(302) (Preparation of Cell)

(303) LiMn.sub.2O.sub.4 as a cathode active material and a carbon black as a conductivity imparting agent were dry mixed, and the mixture was uniformly dispersed in N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride (PVDF) was dissolved as a binder to prepare a slurry. The resulting slurry was applied to an aluminum foil (square, thickness of 20 m) that is to be a cathode current collector, and the NMP was dried off to prepare a cathode sheet. The resulting cathode sheet had a solid mass ratio of cathode active material:conductivity imparting agent:PVDF=80:10:10.

(304) A commercially available graphite-coated electrode sheet (produced by Hohsen Corp.) was used as an anode sheet.

(305) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 was dissolved as an electrolyte in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution, and a halogen-containing disulfonic acid ester compound prepared in each of the examples and comparative examples was added in an amount of 1.0% by mass as an additive for a non-aqueous electrolyte solution. Thus, a non-aqueous electrolyte solution was prepared.

(306) A cylindrical secondary battery was prepared in such a way that an anode sheet and a cathode sheet were laminated and a polyethylene separator was disposed between the sheets in the resulting non-aqueous electrolyte solution. Further, as Reference Example 3, a cylindrical secondary battery was similarly prepared using the non-aqueous electrolyte solution prepared without adding an additive for a non-aqueous electrolyte solution.

(307) (Measurement of Discharge Capacity Retention and Internal Resistance Ratio)

(308) The resulting cylindrical secondary batteries were subjected to a charge/discharge cycle test under the conditions of a temperature of 25 C., a charging rate of 0.3 C, a discharging rate of 0.3 C, a charge termination voltage of 4.2 V, and a discharge termination voltage of 2.5 V. Table 19 shows discharge capacity retention (%) and internal resistance ratio after 200 cycles.

(309) The discharge capacity retention (%) after 200 cycles was determined by dividing the discharge capacity (mAh) after 200 cycles of the cycle test by the discharge capacity (mAh) after 10 cycles of the cycle test and multiplying the resulting value by 100. Further, the internal resistance ratio after 200 cycles was expressed as a value of the resistance after 200 cycles of the cycle test relative to a value of the resistance before the cycle test taken as 1.

(310) TABLE-US-00019 TABLE 19 Discharge capacity Internal Electrolyte Solvent Additive retention (%) resistance ratio Example 30 LiPF.sub.6 EC/DEC Compound 35 93 1.16 1.0 mol/L (30/70) vol % 1.0% by mass Example 31 LiPF.sub.6 EC/DEC Compound 36 94 1.20 1.0 mol/L (30/70) vol % 1.0% by mass Example 32 LiPF.sub.6 EC/DEC Compound 37 92 1.18 1.0 mol/L (30/70) vol % 1.0% by mass Example 33 LiPF.sub.6 EC/DEC Compound 38 94 1.12 1.0 mol/L (30/70) vol % 1.0% by mass Example 34 LiPF.sub.6 EC/DEC Compound 39 92 1.11 1.0 mol/L (30/70) vol % 1.0% by mass Example 35 LiPF.sub.6 EC/DEC Compound 40 91 1.17 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 41 81 1.71 Example 21 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 42 83 1.65 Example 22 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC Compound 43 78 1.59 Example 23 1.0 mol/L (30/70) vol % 1.0% by mass Reference LiPF.sub.6 EC/DEC None 74 1.83 Example 3 1.0 mol/L (30/70)vol %

(311) Table 19 shows that the cylindrical secondary batteries each using a non-aqueous electrolyte solution containing a halogen-containing disulfonic acid ester compound obtained in each of the examples have a higher discharge capacity retention in a cycle test than the cylindrical secondary batteries each using the non-aqueous electrolyte solution of Reference Example 3 or a non-aqueous electrolyte solution containing a halogen-containing disulfonic acid ester compound of each of the comparative examples. Therefore, in cells such as non-aqueous electrolyte solution secondary cells, the non-aqueous electrolyte solutions containing an additive for a non-aqueous electrolyte solution formed from a halogen-containing disulfonic acid ester compound obtained in each of Examples 30 to 35 provide an SEI with higher stability to charge/discharge cycle on the surface of an electrode of the cells than the non-aqueous electrolyte solutions containing an additive for a non-aqueous electrolyte solution formed from a compound obtained in each of Comparative Examples 21 to 23 and the non-aqueous electrolyte solution of Reference Example 3.

(312) Further, the non-aqueous electrolyte solutions each containing a halogen-containing disulfonic acid ester compound obtained in each of the examples have smaller internal resistance than the non-aqueous electrolyte solution of Reference Example 3 and the non-aqueous electrolyte solutions each containing a halogen-containing disulfonic acid ester compound of each of the comparative examples, and therefore suppress an increase in internal resistance during a cycle test.

EXAMPLE 36

Preparation of phosphorus-containing sulfonic acid ester compound (compound 44) represented by the formula (25) in which R34 is ethyl, R35 is ethyl, and Y2 is hydrogen

(313) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with bromoacetic acid (13.9 g) (0.1 mol) and dimethoxyethane (70.0 g), and triethyl phosphite (16.6 g) (0.1 mol) mixed with dimethoxyethane (20.0 g) was added dropwise at 0 C. over 2 hours. The temperature was gradually increased to room temperature, and the solution was stirred over night and rinsed with water and a saturated saline. The dimethoxyethane was removed by distillation to give a reaction product (30 g).

(314) Next, a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with chlorosulfonic acid (23.3 g) (0.2 mol) mixed with phosphoryl chloride (46 g), and subsequently the reaction product (30 g) prepared above was added dropwise over 1 hour. The reaction product was heated to 100 C. over 2 hours, followed by stirring at the same temperature for 20 hours. Then, phosphoryl chloride was removed by normal pressure distillation, and reduced pressure distillation (2 torr, 160 C.) was carried out to give an oily reaction product (25 g).

(315) Then, water (50 g) was added to the resulting oily reaction product (25 g), followed by stirring at 100 C. for 12 hours. After the completion of the reaction, water was removed by reduced pressure disillation to give a reaction product (20 g). Subsequently, sulfolane (120 g) was added to the resulting reaction solution (20 g) and heated to 100 C. Then, phosphorus oxide (28 g) (0.2 mol) and paraformaldehyde (6 g) (0.2 mol) were alternately added and the contents were kept warm with stirring for 10 hours. After the completion of the reaction, the solution was cooled to room temperature, water (30 g) and acetonitrile (100 g) were added thereto, and the resulting solution was separated. Acetonitrile was removed by reduced pressure distillation, the remaining solution was cooled to 0 C., and water (160 g) was added dropwise thereto to obtain crystals. The crystals were collected by filtration, rinsed with hexane, and dried to give a phosphorus-containing sulfonic acid ester compound (compound 44) (6 g) represented by the formula (25) in which R.sup.34 was ethyl, R.sup.35 was ethyl, and Y.sup.2 was hydrogen. The yield of the compound 44 was 19% based on the amount of the bromoacetic acid.

(316) (Preparation of Non-Aqueous Electrolyte Solution)

(317) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 44 prepared as an additive for a non-aqueous electrolyte solution was added in an amount of 0.5% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 37

(318) A non-aqueous electrolyte solution was prepared in the same manner as in Example 36 except that the amount of the compound 44 was 1.0% by mass in Preparation of non-aqueous electrolyte solution.

EXAMPLE 38

Preparation of phosphorus-containing sulfonic acid ester compound (compound 45) represented by the formula (25) in which R34 is propyl, R35 is propyl, and Y2 is hydrogen

(319) A phosphorus-containing sulfonic acid ester compound (compound 45) (8 g) represented by the formula (25) in which R.sup.34 was propyl, R.sup.35 was propyl, and Y.sup.2 was hydrogen was prepared in the same manner as in Example 37 except that the phosphite tripropyl (20.8 g) (0.1 mol) was used instead of triethyl phosphite (16.6 g) (0.1 mol). The yield of the compound 45 was 23% based on the amount of the bromoacetic acid.

(320) (Preparation of Non-Aqueous Electrolyte Solution)

(321) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 45 prepared as an additive for a non-aqueous electrolyte solution was added in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 39

Preparation of phosphorus-containing sulfonic acid ester compound (compound 46) represented by the formula (26) in which R34 is ethyl, R35 is ethyl, R38 is ethyl, R39 is ethyl, and Y2 is hydrogen

(322) A 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with bromoacetic acid (13.9 g) (0.1 mol) and dimethoxyethane (70.0 g), and triethyl phosphite (16.6 g) (0.1 mol) mixed with dimethoxyethane (20.0 g) was added dropwise at 0 C. over 2 hours. The contents were gradually heated to room temperature, stirred over night, and rinsed with water and a saturated saline. The dimethoxyethane was removed by distillation to give a reaction product (30 g).

(323) Next, to a 200-mL four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was added dropwise chlorosulfonic acid (23.3 g) (0.2 mol) mixed with phosphoryl chloride (46 g) over 1 hour. Sequentially, the reaction product (30 g) obtained above was added dropwise thereto over 1 hour. Then, the solution was heated to 100 C. over 2 hours, and stirred at the same temperature for 20 hours. The phosphoryl chloride was removed by normal pressure distillation, and reduced pressure distillation (2 torr, 160 C.) was carried out to give an oily reaction product (25 g).

(324) Next, a 200-mL four-necked flask was charged with dimethoxyethane (70 g) and ethanol (13.8 g) (0.3 mol), and the solution was cooled to 0 C. The oily reaction product (25 g) obtained above was added dropwise to the solution over 2 hours, followed by dropwise addition of triethylamine (41 g) (0.4 mol) over 2 hours. The solution was continuously stirred for 10 hours to complete the reaction, the reaction solution was filtered to remove an inorganic salt, and toluene (100 g) and water (25 g) were added to the filtrate. Then, an organic phase was separated from the aqueous phase, and the toluene was removed from the organic phase by reduced pressure distillation. Subsequently, the remaining solution was cooled to 0 C., and methanol (40 g) was added dropwise over 3 hours to give crystals. The crystals were separated by filtration and dried under reduced pressure to give a phosphorus-containing sulfonic acid ester compound (compound 46) (10 g) represented by the formula (26) in which R.sup.34 was ethyl, R.sup.35 was ethyl, R.sup.38 was ethyl, R.sup.39 was ethyl, and Y.sup.2 was hydrogen. The yield of the compound 46 was 26% based on the amount of the bromoacetic acid.

(325) (Preparation of Non-Aqueous Electrolyte Solution)

(326) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 46 prepared as an additive for a non-aqueous electrolyte solution was added in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 40

Preparation of phosphorus-containing sulfonic acid ester compound (compound 47) represented by the formula (26) in which r34 is ethyl, r35 is ethyl, r38 is phenyl, r39 is phenyl, and y2 is hydrogen

(327) A phosphorus-containing sulfonic acid ester compound (compound 47) (8 g) represented by the formula (26) in which R.sup.34 was ethyl, R.sup.35 was ethyl, R.sup.38 was phenyl, R.sup.39 was phenyl, and Y.sup.2 was hydrogen was prepared in the same manner as in Example 39 except that phenol (28.2 g) (0.3 mol) was used instead of an ethanol (13.8 g) (0.3 mol). The yield of the compound 47 was 18% based on the amount of the bromoacetic acid.

(328) (Preparation of Non-Aqueous Electrolyte Solution)

(329) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 47 prepared as an additive for a non-aqueous electrolyte solution was added in an amount of 1.0% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

COMPARATIVE EXAMPLE 24

(330) A non-aqueous electrolyte solution was prepared in the same manner as in Example 36 except that no compound 44 was used.

COMPARATIVE EXAMPLE 25

(331) A non-aqueous electrolyte solution was prepared in the same manner as in Example 37 except that 1,3-propane sultone (PS) was used instead of the compound 44.

COMPARATIVE EXAMPLE 26

(332) A non-aqueous electrolyte solution was prepared in the same manner as in Example 37 except that vinylene carbonate (VC) was used instead of the compound 44.

COMPARATIVE EXAMPLE 27

(333) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 26 except that the amount of the vinylene carbonate (VC) was 2.0% by mass.

COMPARATIVE EXAMPLE 28

(334) A non-aqueous electrolyte solution was prepared in the same manner as in Example 37 except that fluoroethylene carbonate (FEC) was used instead of the compound 44.

COMPARATIVE EXAMPLE 29

(335) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 28 except that the amount of the fluoroethylene carbonate (FEC) was 2.0% by mass.

(336) <Evaluation>

(337) (LUMO Energy, Standard Enthalpy of Formation (H), Enthalpy Change (H) with Hydrolysis Reaction)

(338) The LUMO (lowest unoccupied molecular orbital) energies of the compounds 44 to 47 prepared in the examples were derived using the Gaussian 03 software. The results are shown in Table 20.

(339) Further, the standard enthalpies of formation (H) of the compounds 44 to 47 prepared in the examples were derived using the MOPAC 97 software. The results are shown in Table 20.

(340) Further, the enthalpy changes (H) with hydrolysis reaction of the compounds 44 to 47 prepared in the examples were derived using the Gaussian 03 software. The results are shown in Table 20.

(341) TABLE-US-00020 TABLE 20 LUMO energy H H Structure (eV) (kcal/mol) (kcal/mol) Compound 44 0 0.55 172.7 2.8 Compound 45 0.53 178.9 3.1 Compound 46 0.21 156.3 3.6 Compound 47 0.88 173.3 3.8

(342) Table 20 shows that the phosphorus-containing sulfonic acid ester compounds (compounds 44 to 47) represented by the formula (24) have a negative LUMO energy of about 0.21 eV to about 0.88 eV, and these phosphorus-containing sulfonic acid ester compounds according to the additive for a non-aqueous electrolyte solution of the present invention have a low LUMO energy. Therefore, in cases where the compounds 44 to 47 are used as an additive for a non-aqueous electrolyte solution for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the compounds 44 to 47 are electrochemically reduced prior to electrochemical reduction of solvents of non-aqueous electrolyte solutions (for example, cyclic carbonate and chain carbonate: LUMO energy of about 1.2 eV), and an SEI is formed on an electrode, whereby decomposition of solvent molecules in an electrolyte solution can be suppressed. As a result, a high resistant film produced by decomposition of the solvent is less likely to be formed on an electrode to probably improve cell performance.

(343) Table 20 shows that the phosphorus-containing sulfonic acid ester compounds (compounds 44 to 47) represented by the formula (24) have a standard enthalpy of formation (H) of about 156.3 kcal/mol to about 178.9 kcal/mol. That is, the compounds 44 to 47 according to the present invention have excellent storage stability in a non-aqueous electrolyte solution. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(344) Further, Table 20 shows that the phosphorus-containing sulfonic acid ester compounds (compounds 44 to 47) represented by the formula (24) have an enthalpy change (H) with hydrolysis reaction of about 2.8 kcal/mol to about 3.8 kcal/mol. That is, the compounds 44 to 47 according to the present invention are also stable to moisture. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(345) Thus, the phosphorus-containing sulfonic acid ester compounds represented by the formula (24) according to the additive for a non-aqueous electrolyte solution of the present invention have a sufficiently low LUMO energy, excellent storage stability when contained in a non-aqueous electrolyte solution as an additive for a non-aqueous electrolyte solution, and excellent stability to moisture. This shows that such compounds are effective as a novel additive for a non-aqueous electrolyte solution capable of forming a stable SEI on an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(346) (Preparation of Cell)

(347) LiMn.sub.2O.sub.4 as a cathode active material and a carbon black as a conductivity imparting agent were dry mixed, and the mixture was uniformly dispersed in N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride (PVDF) was dissolved as a binder to prepare a slurry. The resulting slurry was applied to an aluminum foil (square, thickness of 20 m) that is to be a cathode current collector, and the NMP was dried off to prepare a cathode sheet. The resulting cathode sheet had a solid mass ratio of cathode active material:conductivity imparting agent:PVDF=80:10:10.

(348) A commercially available graphite-coated electrode sheet (produced by Hohsen Corp.) was used as an anode sheet.

(349) A cylindrical secondary battery was prepared in such a way that an anode sheet and a cathode sheet were laminated and a polyethylene separator was disposed between the sheets in a non-aqueous electrolyte solution prepared in each of the examples and comparative examples.

(350) (Measurement of Discharge Capacity Retention and Internal Resistance Ratio)

(351) The resulting cylindrical secondary batteries each using a non-aqueous electrolyte solution obtained in each of the examples and comparative examples were subjected to a charge/discharge cycle test under the conditions of a temperature of 25 C., a charging rate of 0.3 C, a discharging rate of 0.3 C, a charge termination voltage of 4.2 V, and a discharge termination voltage of 2.5 V. Table 21 shows discharge capacity retention (%) and internal resistance ratio after 200 cycles.

(352) The discharge capacity retention (%) after 200 cycles was determined by dividing the discharge capacity (mAh) after 200 cycles of the cycle test by the discharge capacity (mAh) after 10 cycles of the cycle test and multiplying the resulting value by 100. Further, the internal resistance ratio after 200 cycles was expressed as a value of the resistance after 200 cycles of the cycle test relative to a value of the resistance before the cycle test taken as 1.

(353) TABLE-US-00021 TABLE 21 Internal Discharge capacity resistance Electrolyte Solvent Additive retention (%) ratio Example 36 LiPF.sub.6 EC/DEC Compound 44 91 1.34 1.0 mol/L (30/70) vol % 0.5% by mass Example 37 LiPF.sub.6 EC/DEC Compound 44 96 1.21 1.0 mol/L (30/70) vol % 1.0% by mass Example 38 LiPF.sub.6 EC/DEC Compound 45 98 1.18 1.0 mol/L (30/70) vol % 1.0% by mass Example 39 LiPF.sub.6 EC/DEC Compound 46 96 1.20 1.0 mol/L (30/70) vol % 1.0% by mass Example 40 LiPF.sub.6 EC/DEC Compound 47 95 1.25 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC None 74 1.83 Example 24 1.0 mol/L (30/70) vol % Comparative LiPF.sub.6 EC/DEC PS 77 1.68 Example 25 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 83 1.69 Example 26 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 84 1.53 Example 27 1.0 mol/L (30/70) vol % 2.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 81 1.66 Example 28 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 83 1.67 Example 29 1.0 mol/L (30/70) vol % 2.0% by mass

(354) Table 21 shows that the cylindrical secondary batteries each using a non-aqueous electrolyte solution containing a phosphorus-containing sulfonic acid ester compound of each of the examples have a higher discharge capacity retention in a cycle test than the cylindrical secondary batteries each using a non-aqueous electrolyte solution of each of the comparative examples. Therefore, in cells such as non-aqueous electrolyte solution secondary cells, the non-aqueous electrolyte solutions each containing an additive for a non-aqueous electrolyte solution formed from a phosphorus-containing sulfonic acid ester compound of each of the examples provide an SEI with higher stability to charge/discharge cycle on the surface of an electrode of the cells than the non-aqueous electrolyte solutions of the comparative examples. Further, the non-aqueous electrolyte solutions each containing a phosphorus-containing sulfonic acid ester compound of each of the examples can keep an internal resistance ratio lower than the non-aqueous electrolyte solutions of the comparative examples, and can suppress an increase in internal resistance during a cycle test.

EXAMPLE 41

(355) Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of EC:DEC=30:70 to prepare a non-aqueous solvent mixture. LiPF.sub.6 as an electrolyte was dissolved in the mixture so as to prepare a 1.0 mol/L LiPF.sub.6 solution. The compound 48 shown in Table 22 as an additive for a non-aqueous electrolyte solution was added in an amount of 0.5% by mass of the total weight of the solution containing the non-aqueous solvent mixture and the electrolyte. Thus, a non-aqueous electrolyte solution was prepared.

EXAMPLE 42

(356) A non-aqueous electrolyte solution was prepared in the same manner as in Example 41 except that the amount of the compound 48 was 1.0% by mass.

EXAMPLE 43

(357) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that the compound 49 shown in Table 22 was used instead of the compound 48.

EXAMPLE 44

(358) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that the compound 50 shown in Table 22 was used instead of the compound 48.

EXAMPLE 45

(359) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that the compound 51 shown in Table 22 was used instead of the compound 48.

EXAMPLE 46

(360) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that the compound 52 shown in Table 22 was used instead of the compound 48.

EXAMPLE 47

(361) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that the compound 53 shown in Table 22 was used instead of the compound 48.

COMPARATIVE EXAMPLE 30

(362) A non-aqueous electrolyte solution was prepared in the same manner as in Example 41 except that no compound 48 was used.

COMPARATIVE EXAMPLE 31

(363) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that 1,3-propane sultone (PS) was used instead of the compound 48.

COMPARATIVE EXAMPLE 32

(364) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that vinylene carbonate (VC) was used instead of the compound 48.

COMPARATIVE EXAMPLE 33

(365) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 32 except that the amount of the vinylene carbonate (VC) was 2.0% by mass.

COMPARATIVE EXAMPLE 34

(366) A non-aqueous electrolyte solution was prepared in the same manner as in Example 42 except that fluoroethylene carbonate (FEC) was used instead of the compound 48.

COMPARATIVE EXAMPLE 35

(367) A non-aqueous electrolyte solution was prepared in the same manner as in Comparative Example 34 except that the amount of the fluoroethylene carbonate (FEC) was 2.0% by mass.

(368) <Evaluation>

(369) (LUMO Energy, Standard Enthalpy of Formation (H), Enthalpy Change (H) with Hydrolysis Reaction)

(370) The LUMO (lowest unoccupied molecular orbital) energies of the compounds 48 to 53 shown in Table 22 were derived using the Gaussian 03 software. The results are shown in Table 22.

(371) Further, the standard enthalpies of formation (H) of the compounds 48 to 53 were derived using the MOPAC 97 software. The results are shown in Table 22.

(372) Further, the enthalpy changes (H) with hydrolysis reaction of the compounds 48 to 53 were derived using the Gaussian 03 software. The results are shown in Table 22.

(373) TABLE-US-00022 TABLE 22 LUMO H H energy (kcal/ (kcal/ Structure (eV) mol) mol) Compound 48 2.23 207.8 4.6 Compound 49 1.99 199.3 4.8 Compound 50 2.29 183.5 4.2 Compound 51 2.01 178.7 4.0 Compound 52 2.38 210.2 3.8 Compound 53 1.89 208.3 3.7

(374) Table 22 shows that the silyl sulfonic acid ester compounds (compounds 48 to 53) represented by the formula (27) have a LUMO energy of about 1.89 eV to about 2.38 eV, and these silyl sulfonic acid ester compounds according to the additive for a non-aqueous electrolyte solution of the present invention have a low LUMO energy. Therefore, in cases where the compounds 48 to 53 are used as an additive for a non-aqueous electrolyte solution for electrical storage devices such as non-aqueous electrolyte solution secondary cells, the compounds 48 to 53 are electrochemically reduced prior to electrochemical reduction of solvents of non-aqueous electrolyte solutions (for example, cyclic carbonate and chain carbonate: LUMO energy of about 1.2 eV), and an SEI is formed on an electrode, whereby decomposition of solvent molecules in an electrolyte solution can be suppressed. As a result, a high resistant film produced by decomposition of the solvent is less likely to be formed on an electrode to probably improve cell performance.

(375) Table 22 shows that the silyl sulfonic acid ester compounds (compounds 48 to 53) represented by the formula (27) have a standard enthalpy of formation (H) of about 178.7 kcal/mol to about 210.2 kcal/mol. That is, the compounds 48 to 53 according to the present invention have excellent storage stability in a non-aqueous electrolyte solution. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on the surface of an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(376) Further, Table 22 shows that the silyl sulfonic acid ester compounds (compounds 48 to 53) represented by the formula (27) have an enthalpy change (H) with hydrolysis reaction of about 3.7 kcal/mol to about 4.8 kcal/mol. That is, the compounds 48 to 53 according to the present invention are also stable to moisture. Further, in cases where such a non-aqueous electrolyte solution is used for electrical storage devices such as secondary batteries, the compounds subjected to electrochemical reduction decomposition enables formation of an SEI on an electrode. As a result, decomposition of solvent molecules in an electrolyte solution can be suppressed.

(377) Thus, the silyl sulfonic acid ester compounds represented by the formula (27) according to the additive for a non-aqueous electrolyte solution of the present invention have a sufficiently low LUMO energy, excellent storage stability when contained in a non-aqueous electrolyte solution as an additive for a non-aqueous electrolyte solution, and excellent stability to moisture. This shows that such compounds are effective as a novel additive for a non-aqueous electrolyte solution capable of forming a stable SEI on an electrode of electrical storage devices such as non-aqueous electrolyte solution secondary cells.

(378) (Preparation of Cell)

(379) LiMn.sub.2O.sub.4 as a cathode active material and a carbon black as a conductivity imparting agent were dry mixed, and the mixture was uniformly dispersed in N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride (PVDF) was dissolved as a binder to prepare a slurry. The resulting slurry was applied to an aluminum foil (square, thickness of 20 m) that is to be a cathode current collector, and the NMP was dried off to prepare a cathode sheet. The resulting cathode sheet had a solid mass ratio of cathode active material:conductivity imparting agent:PVDF=80:10:10.

(380) A commercially available graphite-coated electrode sheet (produced by Hohsen Corp.) was used as an anode sheet.

(381) A cylindrical secondary battery was prepared in such a way that an anode sheet and a cathode sheet were laminated and a polyethylene separator was disposed between the sheets in a non-aqueous electrolyte solutions prepared in each of the examples and comparative examples.

(382) (Evaluation of Discharge Capacity Retention and Internal Resistance Ratio)

(383) The resulting cylindrical secondary batteries each using a non-aqueous electrolyte solution obtained in each of the examples and comparative examples were subjected to a charge/discharge cycle test under the conditions of a temperature of 25 C., a charging rate of 0.3 C, a discharging rate of 0.3 C, a charge termination voltage of 4.2 V, and a discharge termination voltage of 2.5 V. Table 23 shows discharge capacity retention (%) and internal resistance after 200 cycles. The discharge capacity retention (%) after 200 cycles was determined by dividing the discharge capacity (mAh) after 200 cycles of the cycle test by the discharge capacity (mAh) after 10 cycles of the cycle test and multiplying the resulting value by 100. Further, the internal resistance ratio after 200 cycles was expressed as a value of the resistance after 200 cycles of the cycle test relative to a value of the resistance before the cycle test taken as 1.

(384) TABLE-US-00023 TABLE 23 Discharge capacity Internal Electrolyte Solvent Additive retention (%) resistance ratio Example 41 LiPF.sub.6 EC/DEC Compound 48 92 1.21 1.0 mol/L (30/70) vol % 0.5% by mass Example 42 LiPF.sub.6 EC/DEC Compound 48 96 1.15 1.0 mol/L (30/70) vol % 1.0% by mass Example 43 LiPF.sub.6 EC/DEC Compound 49 94 1.10 1.0 mol/L (30/70) vol % 1.0% by mass Example 44 LiPF.sub.6 EC/DEC Compound 50 95 1.13 1.0 mol/L (30/70) vol % 1.0% by mass Example 45 LiPF.sub.6 EC/DEC Compound 51 95 1.10 1.0 mol/L (30/70) vol % 1.0% by mass Example 46 LiPF.sub.6 EC/DEC Compound 52 93 1.19 1.0 mol/L (30/70) vol % 1.0% by mass Example 47 LiPF.sub.6 EC/DEC Compound 53 96 1.15 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC None 74 1.83 Example 30 1.0 mol/L (30/70) vol % Comparative LiPF.sub.6 EC/DEC PS 77 1.68 Example 31 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 83 1.69 Example 32 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC VC 84 1.53 Example 33 1.0 mol/L (30/70) vol % 2.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 81 1.66 Example 34 1.0 mol/L (30/70) vol % 1.0% by mass Comparative LiPF.sub.6 EC/DEC FEC 83 1.67 Example 35 1.0 mol/L (30/70) vol % 2.0% by mass

(385) Table 23 shows that the cylindrical secondary batteries each using a non-aqueous electrolyte solution containing a silyl sulfonic acid ester compound of each of the examples have a higher discharge capacity retention in a cycle test than the cylindrical secondary batteries each using a non-aqueous electrolyte solution of each of the comparative examples. Therefore, in cells such as non-aqueous electrolyte solution secondary cells, the non-aqueous electrolyte solutions each containing an additive for a non-aqueous electrolyte solution formed from a silyl sulfonic acid ester compound of each of the examples provide an SEI with higher stability to charge/discharge cycle on the surface of an electrode of the cells than the non-aqueous electrolyte solutions of the comparative examples. Further, the non-aqueous electrolyte solutions each containing a silyl sulfonic acid ester compound of each of the examples have smaller internal resistance, and therefore suppress an increase in internal resistance during a cycle test.

INDUSTRIAL APPLICABILITY

(386) The present invention can provide an additive for a non-aqueous electrolyte solution with excellent storage stability capable of forming a stable SEI on the surface of an electrode to improve cell performance such as a cycle performance, a discharge/charge capacity, and internal resistance, when the additive is used for electrical storage devices such as non-aqueous electrolyte solution secondary cells and electric double layer capacitors.

(387) Further, the present invention can provide a non-aqueous electrolyte solution that contains the additive for a non-aqueous electrolyte solution and an electrical storage device using the non-aqueous electrolyte solution.

REFERENCE SIGNS LIST

(388) 1 Non-aqueous electrolyte solution secondary cell 2 Cathode current collector 3 Cathode active material layer 4 Cathode plate 5 Anode current collector 6 Anode active material layer 7 Anode plate 8 Non-aqueous electrolyte solution 9 Separator