Electrolyte for lithium cell

Abstract

An electrolyte, an electrolyte solvent, and an electrolyte additive, in particular for a lithium cell, include at least one ether. The at least one ether has at least one of the general chemical formula: R11R12R13C(CR14R15)x1-[O(CR31R32)a-(CR33R34)b]c-O(CR24R25)x2-CR21R22R23 and of the general chemical formula: R41R42R43C(CR44R45)y1-O(CR54R55)y2-CR51R52R53.

Claims

1. An electrolyte, comprising: at least one cyclic carbonate and/or at least one acyclic carbonate, and at least one ether, wherein the at least one ether comprises at least one carboxylic acid group, carboxylic ester group, hydroxyl group, thiol group, halogen atom alkenylic group, an aromatic hydrocarbon, a cyclic alkyl group, an aryl group, or a heteroaryl group, and wherein the electrolyte, based on a total weight of the carbonates and ethers, comprises: 50% by weight to 80% by weight of acyclic carbonates; 15% by weight to 40% by weight of cyclic carbonates; and 0.1% by weight to 20% by weight of ethers.

2. The electrolyte according to claim 1, wherein the electrolyte, based on a total weight of the carbonates and ethers, comprises 0.5% by weight to 2% by weight of ethers.

3. The electrolyte according to claim 1, wherein the electrolyte further comprises at least one conductive lithium salt.

4. The electrolyte according to claim 3, wherein the at least one conductive lithium salt is lithium hexafluorophosphate.

5. The electrolyte according to claim 1, wherein the at least one ether comprises at least one of a monoether and an oligoether.

6. An electrolyte comprising: at least one cyclic carbonate and/or at least one acyclic carbonate, and at least one ether comprising the formula:
R.sub.11R.sub.12R.sub.13C(CR.sub.14R.sub.15).sub.x1[O(CR.sub.31R.sub.32).sub.a(CR.sub.33R.sub.34).sub.b].sub.cO(CR.sub.24R.sub.25).sub.x2CR.sub.21R.sub.22R.sub.23
or the formula:
R.sub.41R.sub.42R.sub.43C(CR.sub.44R.sub.45).sub.y1O(CR.sub.54R.sub.55).sub.y2CR.sub.51R.sub.52R.sub.53 where: 1c10, 1a5, 0b5, x.sub.1, x.sub.2, y.sub.1 and y.sub.2 are each independently a number 0 and 5, R.sub.11 or R.sub.41 is a carboxylic acid group, carboxylic ester group, hydroxyl group, thiol group, halogen atom, branched, cyclic alkyl group, alkenyl group, alkoxy group, aryl group, heteroaryl group, aryloxy group, or heteroaryloxy group, R.sub.42 and R.sub.43 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, R.sub.12 and R.sub.13 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, R.sub.21, R.sub.22, R.sub.23 or R.sub.51, R.sub.52, R.sub.53 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, R.sub.14, R.sub.15, R.sub.31, R.sub.32, R.sub.33, R.sub.34, R.sub.24, R.sub.25, R.sub.44, R.sub.45, R.sub.54 and R.sub.55 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, CR.sub.11R.sub.12R.sub.13 or CR.sub.41R.sub.42R.sub.43 is a branched alkyl group, cyclic alkyl group, alkenyl group, aryl group, or heteroaryl group, and CR.sub.21R.sub.22R.sub.23 or CR.sub.51R.sub.52R.sub.53 is a branched alkyl group, cyclic alkyl group, alkenyl group, aryl group, or heteroaryl group.

7. An electrolyte solvent or an electrolyte additive for a lithium cell, of the formula:
R.sub.11R.sub.12R.sub.13C(CR.sub.14R.sub.15).sub.x1[O(CR.sub.31R.sub.32).sub.a(CR.sub.33R.sub.34).sub.b].sub.cO(CR.sub.24R.sub.25).sub.x2CR.sub.21R.sub.22R.sub.23 where: 1c10, 1a5, 0b5, x.sub.1 and x.sub.2 are each independently a number 0 and 5, R.sub.11 is a carboxylic acid group, carboxylic ester group, hydroxyl group, thiol group, halogen atom, branched or cyclic alkyl group, alkenyl group, substituted alkenyl group, cyclic alkenyl group, alkoxy group, branched alkoxy group, cyclic alkoxy group, an aryl group, heteroaryl group, aryloxy group, or a heteroaryloxy group, R.sub.12 and R.sub.13 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, R.sub.21, R.sub.22, R.sub.23 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, and R.sub.14, R.sub.15, R.sub.31, R.sub.32, R.sub.33, R.sub.34, R.sub.24, R.sub.25 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group.

8. The electrolyte solvent or electrolyte additive according to claim 7, where: R.sub.31, R.sub.33, R.sub.12, R.sub.14, R.sub.22, and/or R.sub.24 is an alkyl group, and R.sub.32, R.sub.34, R.sub.13, R.sub.15, R.sub.23, and/or R.sub.25 is hydrogen or an alkyl group.

9. A lithium cell or lithium battery comprising an electrolyte solvent or an electrolyte additive according to claim 7.

10. The electrolyte solvent or electrolyte additive for a lithium cell according to claim 7, wherein: CR.sub.11R.sub.12R.sub.13 is a branched alkyl group, cyclic alkyl group, alkenyl group, substituted or cyclic alkenyl group, aryl group, or heteroaryl group, CR.sub.11R.sub.12R.sub.13 is CH(CH.sub.3).sub.2, CH.sub.2CH(CH.sub.3).sub.2, CH(CH.sub.3)(C.sub.2H.sub.5), C(CH.sub.3).sub.3, C.sub.6H.sub.11, C.sub.6F.sub.11, C.sub.6H.sub.5, or C.sub.6F.sub.5, R.sub.21 is the same as R.sub.11, and/or CR.sub.21R.sub.22R.sub.23 is the same as CR.sub.11R.sub.12R.sub.13.

11. An electrolyte solvent or an electrolyte additive for a lithium cell, of the formula:
R.sub.11R.sub.12R.sub.13C(CR.sub.14R.sub.15).sub.x1[O(CR.sub.31R.sub.32).sub.a(CR.sub.33R.sub.34).sub.b].sub.cO(CR.sub.24R.sub.25).sub.x2CR.sub.21R.sub.22R.sub.23 where: 1c10, 1a5, 0b5, x.sub.1 and x.sub.2 are each independently a number 0 and 5, R.sub.11 is a carboxylic acid group, carboxylic ester group, hydroxyl group, thiol group, halogen atom, branched or cyclic alkyl group, alkenyl group, substituted alkenyl group, cyclic alkenyl group, alkoxy group, branched alkoxy group, cyclic alkoxy group, an aryl group, heteroaryl group, aryloxy group, or a heteroaryloxy group, R.sub.12 and R.sub.13 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, R.sub.21, R.sub.22, R.sub.23 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, R.sub.14, R.sub.15, R.sub.31, R.sub.32, R.sub.33, R.sub.34, R.sub.24, R.sub.25 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, and R.sub.11 is CO.sub.2H, CO.sub.2CH.sub.3, CO.sub.2C.sub.2H.sub.5, SH, or OH.

12. An electrolyte solvent or electrolyte additive for a lithium cell, of the general chemical formula:
R.sub.41R.sub.42R.sub.43C(CR.sub.44R.sub.45).sub.y1O(CR.sub.54R.sub.55).sub.y2CR.sub.51R.sub.52R.sub.53 where: y.sub.1 and y.sub.2 are each independently a number 0 and 5, R.sub.41 is CO.sub.2H, CO.sub.2CH.sub.3, CO.sub.2C.sub.2H.sub.5, SH, or OH, and R.sub.42 and R.sub.43 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, or CR.sub.41R.sub.42R.sub.43 is C.sub.6H.sub.11, C.sub.6F.sub.11, C.sub.6H.sub.5, or C.sub.6F.sub.5, R.sub.51, R.sub.52, R.sub.53 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, or CR.sub.51R.sub.52R.sub.53 is a branched alkyl group, a cyclic alkyl group, an alkenyl group, an aryl group, or a heteroaryl group, and R.sub.44, R.sub.45, R.sub.54, and R.sub.55 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group.

13. The electrolyte solvent or electrolyte additive as claimed in claim 12, where R.sub.41 is the same as R.sub.51 or where CR.sub.41R.sub.42R.sub.43 is the same as CR.sub.51R.sub.52R.sub.53.

14. An electrolyte solvent or electrolyte additive for a lithium cell, of the general chemical formula:
R.sub.41R.sub.42R.sub.43C(CR.sub.44R.sub.45).sub.y1O(CR.sub.54R.sub.55).sub.y2CR.sub.51R.sub.52R.sub.53 where: y.sub.1 and y.sub.2 are each independently a number 0 and 5, R.sub.41 is a carboxylic acid group, a carboxylic ester group, a hydroxyl group, a thiol group, a halogen atom, a cyclic alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group, and R.sub.42 and R.sub.43 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, or CR.sub.41R.sub.42R.sub.43 is a cyclic alkyl group, an alkenyl group, an aryl group, or a heteroaryl group, R.sub.51, R.sub.52, R.sub.53 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, or CR.sub.51R.sub.52R.sub.53 is a branched alkyl group, a cyclic alkyl group, an alkenyl group, an aryl group, or a heteroaryl group, and R.sub.44, R.sub.45, R.sub.54, and R.sub.55 are each independently hydrogen, a carboxylic acid group, a carboxylic ester group, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group, and R.sub.42 and/or R.sub.44 and/or R.sub.52 and/or R.sub.54 are an alkyl group, and where R.sub.43 and/or R.sub.45 and/or R.sub.53 and/or R.sub.55 are hydrogen or an alkyl group.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and advantageous configurations of the subject matter of the disclosure are illustrated by the drawings and elucidated in the description which follows. It should be noted here that the drawings are merely of descriptive character and are not intended to restrict the disclosure in any way at all. The drawings show:

(2) FIG. 1 a schematic view of a lithium ion cell during the charging operation; and

(3) FIG. 2 a schematic view of the lithium ion cell shown in FIG. 1 during the discharging operation.

DETAILED DESCRIPTION

(4) FIGS. 1 and 2 show that the lithium ion cell has an anode (negative electrode) 1 and a cathode (positive electrode) 2, separated spatially from one another by a porous separator 7, for example made from polyethylene and/or polypropylene. The anode 1 may comprise, for example, graphite (C.sub.6) and the cathode 2 may comprise a metal oxide (LiMO.sub.2, LiM.sub.yO.sub.z) and/or metal phosphate, for example lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium cobalt oxide, a spinel such as lithium manganese oxide (LiMn.sub.2O.sub.4) and/or lithium iron phosphate (LiFePO.sub.4).

(5) FIGS. 1 and 2 show that the anode 1 is in contact with an anode output conductor 5, for example made from copper, and the cathode 2 with a cathode output conductor 6, for example made from aluminum. In the context of the diagram shown in FIGS. 1 and 2, the anode output conductor 5 and the cathode output conductor 6 are electrically connected to one another via an ampere meter 8.

(6) FIGS. 1 and 2 further indicate that the cell includes an electrolyte 3 comprising an electrolyte solvent or electrolyte solvent mixture that coordinates and solvates lithium ions 4. In addition, the electrolyte 3 may comprise a lithium-containing conductive salt (conductive lithium salt), for example lithium hexafluorophosphate (LiPF.sub.6). As electrolyte solvent, the electrolyte 3 may especially comprise at least one (oligo)ether of the general chemical formula (1) and/or a (mono)ether of the general chemical formula (2). Optionally, the electrolyte 3 may additionally comprise at least one cyclic carbonate, for example ethylene carbonate (EC), and/or at least one acyclic carbonate.

(7) FIG. 1 illustrates that, during the charging operation, lithium ions 4 (Li.sup.+) leaving the cathode 2 (Li.sub.(1-x)MO.sub.2, Li.sub.(1-x)M.sub.yO.sub.z) are solvated by the electrolyte 3. The lithium ions 4 solvated in the electrolyte 3 then migrate through the porous separator 7 to the anode 1, where they intercalate into the graphite (Li.sub.xC.sub.6). At the same time, electrons e.sup. move from the cathode output conductor 6 to the anode output conductor, i.e. electrical current flowsthrough the output conductors 5, 6 and the ampere meter 8from the anode 1 to the cathode 2.

(8) FIG. 2 illustrates that, during the discharging operation, this process runs in reverse, with movement of electrons e.sup. from the anode output conductor 5 to the cathode output conductor 6, i.e. flow of electrical currentthrough the output conductors 5, 6 and the ampere meter 8from the cathode 2 to the anode 1, and with deintercalation of the lithium ions 4 (Li.sup.+) out of the graphite (Li.sub.xC.sub.6) and solvation by the electrolyte 3 and then migration, solvated in the electrolyte 3, through the porous separator 7 to the cathode 2 (Li.sub.(1-x)MO.sub.2, Li.sub.(1-x)M.sub.yO.sub.z) and intercalation into the material thereof.

(9) The charging and discharging operation can be expressed by the following equation:
C.sub.6+LiMO.sub.2.Math.Li.sub.xC.sub.6+Li.sub.(1-x)MO.sub.2.