Method for producing electrode/separator laminate, and lithium-ion rechargeable battery

Abstract

To provide a method for producing an electrode/separator laminate which, when producing the electrode/separator laminate by subjecting the electrode and separator with adhesive layer to thermocompression bonding, the separator and the electrode can be bonded with adequate adhesion, without detriment to ion conductivity. [Solution] This method for producing an electrode/separator laminate includes a step in which a separator with adhesive layer comprising a porous polyolefin film having an adhesive layer at least on one side, and an electrode which has an electrode active substance layer containing an electrode active substance and an electrode binder, are laminated in such a manner that the adhesive layer and the electrode active substance layer touch one another, and are subsequently subjected to thermocompression.

Claims

1. A method for producing laminate of electrode and separator comprising, a step of laminating a separator with adhesive layer which comprises an adhesive layer on at least one side of a porous polyolefin film, and an electrode comprising an electrode active material layer including an electrode active material and an electrode binder, so that said adhesive layer and said electrode active material layer are in contact, then carrying out a thermocompression bonding, wherein said adhesive layer includes a particulate polymer A having a glass transition temperature of −50 to 5° C. and a particulate polymer B having a glass transition temperature of 50 to 120° C., a thickness of said adhesive layer is 0.2 to 1.0 μm, and said thermocompressing bonding is carried out at 50 to 100° C.

2. The method for producing laminate of electrode and separator as set forth in claim 1, wherein a number average particle diameter of said particulate polymer A and said particulate polymer B is 0.1 to 1 μm.

3. The method for producing laminate of electrode and separator as set forth in claim 1, wherein said electrode binder includes a particulate polymer having a glass transition temperature of −50 to 5° C.

4. The method for producing laminate of electrode and separator as set forth in claim 1 comprising a step of coating an aqueous dispersion slurry for the adhesive layer including the particulate polymer A and the particulate polymer B, and having the viscosity of 0.001 to 0.1 Pa.Math.s on said porous polyolefin film, and drying thereof, thereby obtaining the separator with adhesive layer.

5. The method for producing laminate of electrode and separator as set forth in claim 4, wherein a solid concentration of said aqueous dispersion slurry for the adhesive layer is 1 to 20 wt %.

6. The method for producing laminate of electrode and separator as set forth in claim 1, wherein a swelling ratio of said particulate polymer A and said particulate polymer B when immersed in a mixed solvent (ethylene carbonate/diethyl carbonate=1/2 (volume ratio)) including lithium salt LiPF.sub.6 (concentration of 1 mol/L) is 1 to 5 times.

7. A lithium ion secondary battery comprising laminate of electrode and separator obtained by the production method as set forth in claim 1.

8. The method for producing laminate of electrode and separator as set forth in claim 2, wherein said electrode binder includes a particulate polymer having a glass transition temperature of −50 to 5° C.

9. The method for producing laminate of electrode and separator as set forth in claim 2 comprising a step of coating an aqueous dispersion slurry for the adhesive layer including the particulate polymer A and the particulate polymer B, and having the viscosity of 0.001 to 0.1 Pa.Math.s on said porous polyolefin film, and drying thereof, thereby obtaining the separator with adhesive layer.

10. The method for producing laminate of electrode and separator as set forth in claim 3 comprising a step of coating an aqueous dispersion slurry for the adhesive layer including the particulate polymer A and the particulate polymer B, and having the viscosity of 0.001 to 0.1 Pa.Math.s on said porous polyolefin film, and drying thereof, thereby obtaining the separator with adhesive layer.

11. The method for producing laminate of electrode and separator as set forth in claim 2, wherein a swelling ratio of said particulate polymer A and said particulate polymer B when immersed in a mixed solvent (ethylene carbonate/diethyl carbonate=1/2 (volume ratio)) including lithium salt LiPF.sub.6 (concentration of 1 mol/L) is 1 to 5 times.

12. The method for producing laminate of electrode and separator as set forth in claim 3, wherein a swelling ratio of said particulate polymer A and said particulate polymer B when immersed in a mixed solvent (ethylene carbonate/diethyl carbonate=1/2 (volume ratio)) including lithium salt LiPF.sub.6 (concentration of 1 mol/L) is 1 to 5 times.

13. The method for producing laminate of electrode and separator as set forth in claim 4, wherein a swelling ratio of said particulate polymer A and said particulate polymer B when immersed in a mixed solvent (ethylene carbonate/diethyl carbonate=1/2 (volume ratio)) including lithium salt LiPF.sub.6 (concentration of 1 mol/L) is 1 to 5 times.

14. The method for producing laminate of electrode and separator as set forth in claim 5, wherein a swelling ratio of said particulate polymer A and said particulate polymer B when immersed in a mixed solvent (ethylene carbonate/diethyl carbonate=1/2 (volume ratio)) including lithium salt LiPF.sub.6 (concentration of 1 mol/L) is 1 to 5 times.

15. A lithium ion secondary battery comprising laminate of electrode and separator obtained by the production method as set forth in claim 2.

16. A lithium ion secondary battery comprising laminate of electrode and separator obtained by the production method as set forth in claim 3.

17. A lithium ion secondary battery comprising laminate of electrode and separator obtained by the production method as set forth in claim 4.

18. A lithium ion secondary battery comprising laminate of electrode and separator obtained by the production method as set forth in claim 5.

19. A lithium ion secondary battery comprising laminate of electrode and separator obtained by the production method as set forth in claim 6.

20. The method for producing laminate of electrode and separator as set forth in claim 1, wherein a weight ratio (A/B) between the particulate polymer A and the particulate polymer B is within the range of 10/90 to 20/80.

Description

EXAMPLE

(1) Hereinafter, the present invention will be described based on the examples, however the present invention is not be limited thereto. Note that, parts and % in the present examples are based on the weight unless mentioned otherwise. In the examples and the comparative examples, various physical properties are evaluated as following.

(2) [The Glass Transition Temperature of the Particulate Polymer]

(3) The temperature was measured using the differential scanning calorimetry at the temperature rising speed of 10° C./min, then the intersection between the tangent lines of the measured base line and the inflection point (the point where the upwards convex curve changes to downward concave curve) was determined as the glass transition point (Tg).

(4) [The Average Thickness of the Adhesive Layer]

(5) The average thickness of the adhesive layer was determined as the difference between the average thickness of the separator with the adhesive layer, and the average thickness of the porous polyolefin film. The average thickness was measured for each of the porous polyolefin film and the separator with adhesive layer using high accuracy film thickness measuring device (made by TOSEI ENGINEERING CORP.), then average value was taken from five measuring points. Note that, in case the adhesive layer was formed on both sides of the porous polyolefin film, the average value of both sides respectively is divided by two thereby the average thickness was obtained.

(6) [The Permeability of the Separator for the Secondary Battery]

(7) The test specimen was obtained by cutting the separator with adhesive layer into a size of width 5 cm×length 5 cm. Then, for this test specimen, Gurley value (sec/100 cc) was measured using Gurley measurement apparatus (SMOOTH & POROSITY METER (measuring diameter: φ2.9 cm) made by KUMAGAI RIKI KOGYO Co., Ltd.), thereby the permeability X of the separator with the adhesive layer before the thermocompression bonding was determined.

(8) The separator with adhesive layer cutout in square of width 5 cm×length 5 cm, and the release film (product name “PET38AL-5” made by Lintec Corporation) cut out in a square of width 3 cm×length 3 cm were stacked against each other, then it was pressed for 2 minutes under the condition of 80° C. and 1 MPa. Then, the release film was peeled off, and for the separator with adhesive layer of after being peeled off, the Gurley value was measured by the same method described in above, thereby the permeability Y of the separator with the adhesive layer of after the thermocompression bonding was determined. Note that, the Gurley value was used as the substitute of the ionic conductivity.

(9) [The Electrode Adhesiveness of the Separator for the Secondary Battery]

(10) The separator with adhesive layer cutout in square of width 5 cm×length 5 cm and the negative electrode plate cut out in a square of width 3 cm×length 3 cm were stacked against each other, then it was pressed for 2 minutes under the condition of 80° C. and 1 MPa, thereby the laminate was obtained. The obtained laminate was cut out into a parallelepiped shape of width 1 cm×length 5 cm to make a test specimen, then the negative electro plate side was fixed using a scotch tape (those defined by JIS Z1522) on the testing table of the peel tester. Then, the stress when one end of the separator pulled towards 180 degrees direction at the tensile speed of 50 mm/min for peeling was measured. The measurements were carried out for three times, and the average values were determined, then evaluated based on the following standard. The larger the stress is, the higher the adhesiveness between the electrode is.

(11) A: The stress is 0.15 N/m or more.

(12) B: The stress is less than 0.15 N/m.

(13) [The Rate Characteristic of the Battery]

(14) The charge-discharge cycle of wherein 10 cells of the full-cell coin shape battery was charged up to 4.2 V by the constant current method of 0.1 C and 25° C., then discharged to 3.0 V by the constant current method of 0.1 C; and the charge-discharge cycle wherein charging up to 4.2 V by the constant current method of 0.2 C and 25° C., then discharged to 3.0 V by the constant current method of 1.0 C, were each carried out for one (1 cycle). The ratio of the discharge capacity at 1.0 C against the discharge capacity at 0.1 C was calculated in a percentile (=(the discharge capacity at 1.0 C)/(the discharge capacity at 1.0 C)×100) thereby the charge-discharge rate characteristic was determined, and it was evaluated based on the following standard. The larger this value is, the smaller the internal resistance is, and hence it indicates that high speed charge-discharge is possible.

(15) A: The charge-discharge rate characteristic is 80% or more.

(16) B: The charge-discharge rate characteristic is 75% or more and less than 80%.

(17) C: The charge-discharge rate characteristic is 70% or more and less than 75%.

(18) D: The charge-discharge rate characteristic is less than 70%.

(19) [The High Temperature Cycle Characteristic of the Battery]

(20) Under the atmosphere of 60° C., 10 cells of the full-cell coin shape battery was charged up to 4.2 V by the constant current method of 0.1 C and 25° C., then discharged to 3.0 V, and this charge-discharge was carried out for 50 times (50 cycles) to measure the battery capacity. The average value of 10 cells was defined as the measured value. Further, the ratio of the battery capacity after completing 5 cycles with respect to that of 50 cycles were calculated in a percentile (=(the battery capacity after completing 50 cycles)/(the battery capacity after completing 5 cycles)×100) thereby the charge-discharge capacity maintaining rate was obtained, and this was set as the evaluation standard of the cycle characteristic. The higher this value is, the more excellent the high temperature cycle characteristic is.

(21) A: The charge-discharge capacity maintaining rate is 80% or more.

(22) B: The charge-discharge capacity maintaining rate is 70% or more and less than 80%.

(23) C: The charge-discharge capacity maintaining rate is 60% or more and less than 70%.

(24) D: The charge-discharge capacity maintaining rate is less than 60%.

(25) [The Electrolytic Solution Swelling Ratio of the Particulate Polymer]

(26) Each of the aqueous dispersion of the particulate polymer was casted on the polytetrafluoroethylene sheet so that the thickness after the drying was 1 mm, and the casted film was obtained by drying. This casted film was cut into a size of 2 cm×2 cm and weighed (the weight A before immersing), then it was immersed in the electrolytic solution of 60° C. for 72 hours. The immersed film was pulled out, and wiped by a towel paper and weighed (the weight B after immersing). The electrolytic solution swelling ratio of the binder was calculated from the following formula.

(27) Note that, as for the electrolytic solution, the solution wherein LiPF.sub.6 dissolved in a concentration of 1 mol/litter in the mixed solvent which is the mixture of ethylenecarbonate (EC) and diethylcarbonate (DEC) of EC/DEC=1/2 (the capacity ratio at 20° C.) was used.
The swelling ratio(times)=B/A×100(%)

Example 1

(28) (1-1. The Production of the Particulate Polymer A)

(29) To the reactor equipped with the stirrer, 70 parts of ion exchange water, 0.15 parts of sodium lauryl sulfate (“EMAL 2F” made by Kao Corporation) as emulsifier, and 0.5 parts of ammonium persulfate were supplied, and the vapor part was substituted with nitrogen gas, further the temperature was raised to 60° C.

(30) On the other hand, in other container, 50 parts of ion exchange water, 0.5 parts of sodium dodecylbenzenesulfonate, 94.8 parts of butyl acrylate as the polymerizable monomer, 2 parts of acrylonitrile, 2 parts of methacrylic acid, 1.2 parts of N-methylol acrylamide were mixed, thereby the monomer mixture was obtained. This monomer mixture was continuously added to said reactor using 4 hours, thereby the polymerization was carried out. During the addition, the reaction was carried out at 60° C. After completing the addition, it was stirred for 3 hours at 70° C. and the reaction was terminated, thereby the aqueous dispersion of the particulate polymer A1 was produced.

(31) The number average particle diameter of the obtained particulate polymer A1 was 0.36 μm, and the glass transition temperature was −38° C. Also, in regards with the obtained particulate polymer A1, the electrolytic solution swelling ratio was measured. The result is shown in Table 1.

(32) (1-2. The Production of the Particulate Polymer B1)

(33) To the reactor equipped with the stirrer, 70 parts of ion exchange water, 0.15 parts of sodium lauryl sulfate (“EMAL 2F” made by Kao Corporation) as emulsifier, and 0.5 parts of ammonium persulfate were supplied, and the vapor part was substituted with nitrogen gas, further the temperature was raised to 70° C.

(34) On the other hand, in other container, 50 parts of ion exchange water, 0.5 parts of sodium dodecylbenzenesulfonate, 80 parts of styrene and 18 parts of butyl acrylate as the polymerizable monomer, 2 parts of acrylonitrile, 2 parts of methacrylic acid, 1.2 parts of acrylamide were mixed, thereby the monomer mixture was obtained. This monomer mixture was continuously added to said reactor using 3 hours, thereby the polymerization was carried out. During the addition, the reaction was carried out at 70° C. After completing the addition, it was stirred for 3 hours at 70° C. and the reaction was terminated, thereby the aqueous dispersion of the particulate polymer B1 was produced.

(35) The number average particle diameter of the obtained particulate polymer B1 was 0.35 μm, and the glass transition temperature was 72° C. Also, in regards with the obtained particulate polymer B1, the electrolytic solution swelling ratio was measured. The result is shown in Table 1.

(36) (1-3. The Production of the Slurry for the Adhesive Layer)

(37) The aqueous dispersion of the particulate polymer A1 obtained in the above step (1-1), and the aqueous dispersion of the particulate polymer B1 obtained in the above step (1-2) were mixed in the water using the impeller stirrer so that the solid weight ratio (A1/B1) is 15/85; then the lubricant (the product name: SN wet 980 made by SAN NOPCO LIMITED) was mixed so that the solid ratio was 5 parts with respect to 100 parts of total solid portion of the particulate polymer A1 and the particulate B1. Then, the aqueous slurry for the adhesive layer was obtained by diluting with the ion exchange water so that the total solid concentration of the particulate polymer A1, the particulate polymer B1 and the lubricant was 3 wt %.

(38) The weight ratio of the particulate polymer A1/the particulate polymer B1/the lubricant of the total solid portion in the slurry for the adhesive layer was 14.29/80.95/4.76. The viscosity of the aqueous dispersion slurry for the adhesive layer was 0.01 Pa.Math.s.

(39) (1-4. The Production of the Separator with the Adhesive Layer)

(40) As the porous polyolefin film, the porous polyethylene film (the thickness of 16 μm, the Gurley value of 147 sec/100 cc) was prepared. To one side of the porous polyethylene film prepared, the aqueous slurry for the adhesive layer was coated, and dried at 50° C. for 10 minutes. Then, to other side of the porous polyethylene film, it was coated in a similar manner; thereby the separator with the adhesive layer comprising the adhesive layer on both sides of the porous polyethylene film was obtained. The average thickness of one side of the adhesive layer of obtained separator was 0.8 μm. For the obtained separator, the evaluation of the permeability, and the evaluation of the electrode adhesiveness with the below described negative electrode were carried out. The results are shown in Table 2.

(41) (1-5. The Production of the Positive Electrode)

(42) To 95 parts of LiCoO.sub.2 as the positive electrode active material, 3 parts of PVDF (polyvinilydene fluoride, product name: KF-1100 made by KUREHA CORPORATION) as the binder was added; then 2 parts of acetylene black and 20 parts of N-methylpyrrolidone (hereinafter, it may be referred as NMP) were further added, and these were mixed by planetary mixer, thereby the slurry for the positive electrode was obtained. This slurry for the positive electrode was coated on one side of the aluminum foil having the thickness of 18 μm, then dried for 3 hours at 120° C., thereby the positive electrode comprising the positive electrode active material layer having the total thickness of 100 μm by carrying out the roll press was obtained.

(43) (1-6. The Production of the Negative Electrode)

(44) 100 parts of graphite having 20 μm of the 50% volume cumulative diameter and the specific surface area of 4.2 m.sup.2/g as the negative electrode active material, and 1 part of solid portion conversion amount of aqueous dispersion of SBR (styrene-butadiene rubber, the glass transition temperature: −10° C., and the numerical average particle diameter of 150 nm) were mixed, and 1.0 part of carboxymethyl cellulose were further mixed to this mixture, then the water is added as the solvent to mix these using planetary mixer; thereby the negative electrode slurry was obtained. This negative electrode slurry was coated on one side of the copper foil having the thickness of 18 μm, then dried for 3 hours at 120° C., thereby the negative electrode comprising the negative electrode active material layer having the total thickness of 60 μm by carrying out the roll press was obtained.

(45) (1-7. The Production of the Battery)

(46) The above obtained positive electrode was cut out in 4.3 cm (including the non-coated part of 1.5 cm)×3.8 cm, thereby the parallelepiped positive electrode was obtained. The above obtained negative electrode was cut out in 4.5 cm (including the non-coated part of 1.5 cm)×4.0 cm, thereby the parallelepiped negative electrode was obtained. Also, the above obtained separator with the adhesive layer was cut out in 3.5 cm×4.5 cm, thereby the parallelepiped separator with the adhesive layer was obtained.

(47) The positive electrode layer was placed along the surface of the parallelepiped separator with the adhesive layer, and also the negative electrode active material layer was placed along the backside thereof, then heat and pressure were applied for 2 minutes at the temperature of 80° C. and the pressure of 1 MPa, and the positive electrode and the negative electrode were carried out with the compression bonding to the separator with the adhesive layer, thereby the negative electrode/the separator with the adhesive layer/the positive electrode laminate was produced.

(48) Then, the aluminum wrapping material cut out in the parallelepiped shape of 18 cm×9 cm was folded in 9 cm×9 cm, then at inside thereof, the negative electrode/the separator with the adhesive layer/the positive electrode laminate was placed; then two parts of the both ends of the aluminum wrapping material was thermally bonded by the heat sealer of 150° C.; then these were fixed, thereby the negative electrode/the separator with the adhesive layer/the positive electrode laminate/aluminum wrapping material container were produced.

(49) To the above obtained negative electrode/the separator with the adhesive layer/the positive electrode laminate/aluminum wrapping material container, the electrolytic solution was introduced so that no air is left, then the container was sealed by thermal bonding using the heat sealer of 150° C.; thereby lithium ion secondary battery (laminate cell) of 9 cm×9 cm was produced. As for the electrolytic solution, the solution wherein LiPF.sub.6 dissolved in a concentration of 1 mol/litter in the mixed solvent which is the mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) of EC/DEC=1/2 (the capacity ratio at 20° C.) was used. For the obtained batter, the rate characteristic and the high temperature cycle characteristic were measured. The result is shown in Table 2.

(50) (The Production of the Particulate Polymers A2-A4, A6-A8, B2-B4, B6 and B7)

(51) The particulate polymers A2-A4, A6-A8, B2-B4, B6 and B7 were obtained by changing the type of the monomer, the used amount, the amount of the emulsifier, and the amount of sodium dodecyl benzene sulfonate as shown in Table 1, of the step (1-1) or step (1-2) of the example 1.

(52) (The Production of the Particulate Polymer A5)

(53) To the reactor equipped with the stirrer, 10 parts in the solid base (that is, the weight base of the particulate polymer A1) of the aqueous dispersion of the particulate polymer A1 obtained in the above step (1-1), 0.15 parts of sodium lauryl sulfate (“EMAL 2F” made by Kao Corporation) as emulsifier, and 0.5 parts of ammonium persulfate were supplied, and the vapor part was substituted with nitrogen gas, further the temperature was raised to 60° C.

(54) On the other hand, in other container, 50 parts of ion exchange water, 0.5 parts of sodium dodecylbenzenesulfonate, 94.8 parts of butyl acrylate as the polymerizable monomer, 2 parts of acrylonitrile, 2 parts of methacrylic acid, 1.2 parts of N-methylol acrylamide were mixed, thereby the monomer mixture was obtained. This monomer mixture was continuously added to said reactor using 4 hours; thereby the polymerization was carried out. During the addition, the reaction was carried out at 60° C. After completing the addition, it was stirred for 3 hours at 70° C. and the reaction was terminated, thereby the aqueous dispersion of the particulate polymer A5 was produced.

(55) The number average particle diameter of the obtained particulate polymer A5 was 0.9 μm, and the glass transition temperature was −38° C.

(56) (The Production of the Particulate Polymer B5)

(57) To the reactor equipped with the stirrer, 10 parts in the solid base (that is, the weight base of the particulate polymer B1) of the aqueous dispersion of the particulate polymer B1 obtained in the above step (1-2), 0.15 parts of sodium lauryl sulfate (“EMAL 2F” made by Kao Corporation) as emulsifier, and 0.5 parts of ammonium persulfate were supplied, and the vapor part was substituted with nitrogen gas, and the temperature was raised to 70° C.

(58) On the other hand, in other container, 50 parts of ion exchange water, 0.5 parts of sodium dodecylbenzenesulfonate, 80 parts of styrene and 18 parts of butyl acrylate as the polymerizable monomer, 2 parts of acrylonitrile, 2 parts of methacrylic acid, 1.2 parts of acrylamide were mixed, thereby the monomer mixture was obtained. This monomer mixture was continuously added to said reactor using 4 hours; thereby the polymerization was carried out. During the addition, the reaction was carried out at 70° C. After completing the addition, it was stirred for 3 hours at 70° C. and the reaction was terminated, thereby the aqueous dispersion of the particulate polymer B5 was produced.

(59) The number average particle diameter of the obtained particulate polymer B5 was 0.9 μm, and the glass transition temperature was 72° C.

(60) TABLE-US-00001 TABLE 1 A1 A2 A3 A4 A5 A6 A7 A8 Monomer BA 94.8 73 88 94.8 94.8 78 48 2EHA 0 0 10 0 0 20 0 EA 86.8 ST 0 25 0 0 0 0 50 AN 2 0 0 2 2 0 0 10 MAA 2 2 2 2 2 0 0 2 NMA 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 E-2F 0.15 0.15 0.15 1 0.3 0.15 0.15 0.15 Las-Na 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5 Glass transition (° C.) −38 −25 −45 −38 −38 −55 10 4 temperature Tg Number average (μm) 0.36 0.35 0.36 0.15 0.9 0.37 0.29 0.37 particle diameter Swelling ratio in the (Times) 4 3 3.1 4 4 2.7 3.1 4 electrolytic solution B1 B2 B3 B4 B5 B6 B7 Monomer BA 18 0 28 18 18 33 0 ST 80 90 70 80 80 65 85 AN 2 2 2 2 2 2 2 MAA 2 10 2 2 2 2 15 AAm 1.2 1.2 1.2 1.2 1.2 1.2 1.2 E-2F 0.15 0.15 0.15 1 0.3 0.15 0.15 Las-Na 0.5 0.5 0.5 0.5 1 0.5 0.5 Glass transition (° C.) 72 115 55 72 72 45 125 temperature Tg Number average (μm) 0.35 0.3 0.35 0.15 0.9 0.35 0.25 particle diameter Swelling ratio in the (Times) 2.5 2.1 2 2.5 2.5 2.1 1.9 electrolytic solution

(61) Note that, in Table 1, BA refers to butyl acrylate, 2EHA refers to 2-ethylhexyl acrylate, EA refers to ethyl acrylate, ST refers to styrene, AN refers to acrylonitrile, MAA refers to methacrylic acid, NMA refers to N-methylol acrylamide, AAm refers to acrylamide, E-2F refers to sodium lauryl sulfate (“EMAL 2F” made by Kao Corporation), and Las-Na refers to sodium dodecylbenzenesulfonate. Also, the particulate polymers A6 and A7 in Table 1 does not satisfy the glass transition temperature of the particulate polymer A defined in the present invention, and the particulate polymers B6 and B7 does not satisfy the glass transition temperature of the particulate polymer B defined in the present invention.

Example 2

(62) Other than using the particulate polymer A2 instead of the particulate polymer A1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 3

(63) Other than using the particulate polymer B2 instead of the particulate polymer B1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 4

(64) Other than using the particulate polymer A3 instead of the particulate polymer A1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 5

(65) Other than using the particulate polymer B3 instead of the particulate polymer B1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 6

(66) Except for making the average thickness of the adhesive layer to 0.95 μm, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 7

(67) Except for making the average thickness of the adhesive layer to 0.25 μm, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 8

(68) Except for setting the temperature of the thermocompression bonding to 95° C. during the step (1-8) of the example 1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 9

(69) Except for setting the temperature of the thermocompression bonding to 55° C. during the step (1-8) of the example 1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 10

(70) Except for using the particulate polymer A4 instead of particulate polymer A1, and using the particulate polymer B4 instead of the particulate polymer B1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 11

(71) Except for using the particulate polymer A5 instead of particulate polymer A1, also using the particulate polymer B5 instead of the particulate polymer B1, and setting the average thickness of the adhesive layer to 0.9 μm, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 12

(72) Except for setting the solid weight ratio (A1/B1) between the particulate polymer A1 and the particulate polymer B1 to 5/95, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 13

(73) Except for setting the solid weight ratio (A1/B1) between the particulate polymer A1 and the particulate polymer B1 to 35/65, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Example 14

(74) Except for using the particulate polymer A8 instead of the particulate polymer A1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 1

(75) Except for using the particulate polymer A6 instead of the particulate polymer A1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 2

(76) Except for using the particulate polymer A7 instead of the particulate polymer A1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 3

(77) Except for using the particulate polymer B6 instead of the particulate polymer B1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 4

(78) Except for using the particulate polymer B7 instead of the particulate polymer B1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 5

(79) Except for setting the average thickness of the adhesive layer to 1.1 nm, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 6

(80) Except for not forming the adhesive layer, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 7

(81) The aqueous dispersion of the particulate polymers A1 and B1 were mixed in NMP so that the solid weight ratio (A1/B1) was 15/85, the water was evaporated using the evaporator, and further it was diluted with NMP so that the solid concentration of polymer A1 and the polymer B1 was 3 wt %; thereby the slurry for the adhesive layer was obtained.

(82) On one side of the porous polyethylene film (thickness of 16 μm, and the Gurley value of 147 sec/100 cc), said slurry for the adhesive layer was coated, and dried for 10 minutes at 60° C. Next, said slurry for the adhesive layer was coated on other side of the porous polyethylene film in a similar manner, thereby the separator with the adhesive layer was obtained. The thickness of one side of the adhesive layer of the obtained separator was 0.8 μm. Then, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

(83) The polymers A1 and B1 were dissolved in the slurry for the adhesive layer, thus the polymers infiltrated into the pores of the separator. As a result, the ionic conductivity of the separator was compromised; further the rate characteristic and the cycle characteristic of the lithium ion secondary battery obtained were deteriorated. Also, the polymers A1 and B1 in the adhesive layer were not particulate form, rather it was film form, and hence the pores of the separator were covered.

Comparative Example 8

(84) Except for setting the temperature of the temperature of the thermocompression bonding to 45° C. during the step (1-8) of the example 1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 9

(85) Except for setting the temperature of the temperature of the thermocompression bonding to 110° C. during the step (1-8) of the example 1, the separator with the adhesive layer, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

Comparative Example 10

(86) The particulate polymer A1 was not used, and the lubricant (the product name: SN wet 980 made by SAN NOPCO LIMITED) was mixed so that the solid ratio was 5 parts with respect to the amount of the polymer B1 (100 parts) in the aqueous dispersion of the particulate polymer B1, then further it was diluted with NMP so that the solid concentration of the particulate polymer B1 and the lubricant was 3 wt %; thereby the slurry for the adhesive layer was obtained.

(87) Except for using the above described slurry for the adhesive layer to obtain the separator with the adhesive layer as similar in the example 1, the electrode/separator laminate and the lithium ion secondary battery was produced as same as the example 1. The results are shown in Table 2.

(88) TABLE-US-00002 TABLE 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Particulate polymer A (Tg) A1(−38) A2(−25) A1(−38) A3(−45) A1(−38) A1(−38) A1(−38) Particulate polymer B (Tg) B1(72) B1(72) B2(115) B1(72) B3(55) B1(72) B1(72) Polymer weight ratio (A/B) 15/85 15/85 15/85 15/85 15/85 15/85 15/85 Average thickness of adhesive layer 0.8 0.8 0.8 0.8 0.8 0.95 0.25 (μm) Thermocompression Temperature 80 80 80 80 80 80 80 bonding condition (° C.) Pressure 1 1 1 1 1 1 1 (MPa) Time (min) 2 2 2 2 2 2 2 Permeability X (before 178 175 180 177 175 245 173 thermocompression bonding) Permeability Y (after 190 184 185 183 187 250 185 thermocompression bonding) Permeability changing rate (Y/X) 1.1 1.1 1.0 1.0 1.1 1.0 1.1 Electrode adhesiveness A A A A A A A Rate characteristic test A A A A A B A Cycle characteristic test A A B A A A B Example Example Example Example Example Example 8 Example 9 10 11 12 13 14 Particulate polymer A (Tg) A1(−38) A1(−38) A4(−38) A5(−38) A1(−38) A1(−38) A8(4) Particulate polymer B (Tg) B1(72) B1(72) B4(72) B5(72) B1(72) B1(72) B1(72) Polymer weight ratio (A/B) 15/85 15/85 15/85 15/85 5/95 35/65 15/85 Average thickness of adhesive layer 0.8 0.8 0.8 0.9 0.8 0.8 0.8 (μm) Thermocompression Temperature 95 55 80 80 80 80 80 bonding condition (° C.) Pressure 1 1 1 1 1 1 1 (MPa) Time (min) 2 2 2 2 2 2 2 Permeability X (before 180 175 175 175 175 175 178 thermocompression bonding) Permeability Y (after 260 186 186 186 186 186 185 thermocompression bonding) Permeability changing rate (Y/X) 1.4 1.1 1.1 1.1 1.1 1.1 1.0 Electrode adhesiveness A A A A A A B Rate characteristic test B A B B A B A Cycle characteristic test A B A A B A B Comparative Comparative Comparative Comparative Comparative example 1 example 2 example 3 example 4 example 5 Particulate polymer A (Tg) A6(−55) A7(10) A1(−38) A1(−38) A1(−38) Particulate polymer B (Tg) B1(72) B1(72) B6(45) B7(125) B1(72) Polymer weight ratio (A/B) 15/85 15/85 15/85 15/85 15/85 Average thickness of adhesive layer 0.8 0.8 0.8 0.8 1.1 (μm) Thermocompression Temperature 80 80 80 80 80 bonding condition (° C.) Pressure 1 1 1 1 1 (MPa) Time (min) 2 2 2 2 2 Permeability X (before 237 190 265 169 185 thermocompression bonding) Permeability Y (after 2730 191 14000 180 14000 thermocompression bonding) Permeability changing rate (Y/X) 11.5 1.0 52.8 1.1 75.7 Electrode adhesiveness A B A B A Rate characteristic test C A C A D Cycle characteristic test B C C C C Comparative Comparative Comparative Comparative Comparative example 6 example 7 example 8 example 9 example 10 Particulate polymer A (Tg) — A1(−38) A1(−38) A1(−38) — Particulate polymer B (Tg) — B1(72) B1(72) B1(72) B1(72) Polymer weight ratio (A/B) — 15/85 15/85 15/85 0/100 Average thickness of adhesive layer 0.8 0.8 0.8 0.8 (μm) Thermocompression Temperature 80 80 45 110 110 bonding condition (° C.) Pressure 1 1 1 1 1 (MPa) Time (min) 2 2 2 2 2 Permeability X (before 147 14000 165 170 171 thermocompression bonding) Permeability Y (after 147 14000 170 14000 175 thermocompression bonding) Permeability changing rate (Y/X) 1.0 1.0 1.0 82.4 1.0 Electrode adhesiveness B A B A B Rate characteristic test A D A D A Cycle characteristic test D C D D D

(89) According to Table 1 and Table 2, for the examples satisfying the requirement of the present invention, the lithium ion secondary battery having excellent reliability (the rate characteristic and the cycle characteristic) were obtained.