Polymer battery and method of manufacture

• US 20020009649A1
• Filed: 06/15/2001
• Published: 01/24/2002
• Est. Priority Date: 06/16/2000
• Status: Active Grant

• Current Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Original Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Inventors: Sato, Takaya, Hata, Kimiyo
• Granted Patent: US 6,696,204 B2
• Time in Patent Office: Days
• US Class Current: 429/306
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 6/168 by additives
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A polymer battery which includes a cell assembly having a positive electrode, a negative electrode, and a separator composed primarily of a fluoropolymer is manufactured by impregnating the cell assembly with an electrolyte composition containing (A) an ion-conductive salt, (B) a solvent in which the ion-conductive salt is soluble and (C) a compound having at least two reactive double bonds per molecule, then reacting the component C compound to form a three-dimensional network structure. The polymer battery has a high safety, a good thermal cycling resistance and robust characteristics even when held at an elevated temperature, making it particularly suitable for use as a lithium secondary cell or a lithium ion secondary cell.

Claims

1. A polymer battery comprising a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

which battery is made by impregnating the cell assembly with an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble, and

(C) a compound having at least two reactive double bonds per molecule,

and reacting the component C compound to form a three-dimensional network structure.

2. The polymer battery of claim 1, wherein the electrolyte composition containing components A to C has an ionic conductivity, as measured by the AC impedance method, of at least 1×

10<sup>−

4</sup> S/cm.

14. The polymer battery of any one of claims 1 to 13, wherein the compound having at least two reactive double bonds per molecule C has at least two reactive double bonds per molecule and constitutes at least 1 wt % of the overall electrolyte composition.

3. A polymer battery comprising a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

which battery is made by impregnating the cell assembly with an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble,

(C) a compound having at least two reactive double bonds per molecule, and

(D) a hydroxyalkyl polysaccharide derivative,

and forming a semi-interpenetrating polymer network structure in which molecular chains on the component D polymer are interlocked with a three-dimensional polymer network structure obtained by crosslinking the component C compound.

4. The polymer battery of claim 3 having a ratio (C₁/C₂)×

100 between the ionic conductivity C₁ of an electrolyte composition which contains components A to D and in which components C and D together form a semi-interpenetrating polymer network structure, and the ionic conductivity C₂ of an electrolyte composition which contains components A, B and C or components A, B and D and does not have a semi-interpenetrating polymer network structure of from 80 to 100%.

5. A polymer battery comprising a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

which battery is made by impregnating the cell assembly with an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble,

(C) a compound having at least two reactive double bonds per molecule, and

(E) a polyvinyl alcohol derivative,

and forming a semi-interpenetrating polymer network structure in which molecular chains on the component E polymer are interlocked with a three-dimensional polymer network structure obtained by crosslinking the component C compound.

6. The polymer battery of claim 5 wherein said polyvinyl alcohol derivative E is a polymeric compound containing polyvinyl alcohol units and having an average degree of polymerization of at least 20 in which some or all of the hydroxyl groups on the polyvinyl alcohol units are substituted with oxyalkylene-containing groups.

7. The polymer battery of claim 5 wherein said polyvinyl alcohol derivatives E is a polymeric compound containing polyvinyl alcohol units and having an average degree of polymerization of at least 20 in which some or all of the hydroxyl groups on the polyvinyl alcohol units are substituted with both oxyalkylene-containing groups and cyano-substituted monovalent hydrocarbon groups.

8. The polymer battery of claim 5 wherein said polyvinyl alcohol derivative E is a polymeric compound containing polyvinyl alcohol units and having an average degree of polymerization of at least 20 in which some or all of the hydroxyl groups on the polyvinyl alcohol units are substituted with cyano-substituted monovalent hydrocarbon groups.

9. The polymer battery of claim 8 wherein the polymeric compound having substituted thereon cyano-substituted monovalent hydrocarbon groups is included in an amount of 0.1 to 8 wt % based on the compound having at least two reactive double bonds per molecule C.

10. The polymer battery of claim 7, 8 or 9 wherein the cyano-substituted monovalent hydrocarbon groups are cyanoethyl groups.

11. The polymer battery of any one of claims 5 to 10 having a ratio (C₁/C₂)×

100 between the ionic conductivity C₁ of an electrolyte composition which contains components A, B, C and E and in which components C and E together form a semi-interpenetrating polymer network structure, and the ionic conductivity C₂ of an electrolyte composition which contains components A, B and C or components A, B and E and does not have a semi-interpenetrating polymer network structure of from 80 to 100%.

12. A polymer battery comprising a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

which battery is made by impregnating the cell assembly with an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble,

(C) a compound having at least two reactive double bonds per molecule, and

(F) a polyglycidol derivative,

and forming a semi-interpenetrating polymer network structure in which molecular chains on the component F polymer are interlocked with a three-dimensional polymer network structure obtained by crosslinking the component C compound.

13. The polymer battery of claim 12 having a ratio (C₁/C₂)×

100 between the ionic conductivity C₁ of an electrolyte composition which contains components A, B, C and F and in which components C and F together form a semi-interpenetrating polymer network structure, and the ionic conductivity C₂ of an electrolyte composition which contains components A, B and C or components A, B and F and does not have a semi-interpenetrating polymer network structure of from 80 to 100%.

15. A method of manufacturing a polymer battery, the method comprising the steps of:

(a) impregnating an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble, and

(C) a compound having at least two reactive double bonds per molecule into a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

then

(b) reacting component C to form a three-dimensional network structure.

16. A method of manufacturing a polymer battery, the method comprising the steps of:

(a) impregnating an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble,

(C) a compound having at least two reactive double bonds per molecule, and

(D) a hydroxyalkyl polysaccharide derivative into a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

then

(b) forming a semi-interpenetrating polymer network structure in which molecular chains on the component D polymer are interlocked with a three-dimensional polymer network structure obtained by crosslinking the component C compound.

17. A method of manufacturing a polymer battery, the method comprising the steps of:

(a) impregnating an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble,

(C) a compound having at least two reactive double bonds per molecule, and

(E) a polyvinyl alcohol derivative into a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

then

(b) forming a semi-interpenetrating polymer network structure in which molecular chains on the component E polymer are interlocked with a three-dimensional polymer network structure obtained by crosslinking the component C compound.

18. A method of manufacturing a polymer battery, the method comprising the steps of:

(a) impregnating an electrolyte composition containing

(A) an ion-conductive salt,

(B) a solvent in which the ion-conductive salt is soluble,

(C) a compound having at least two reactive double bonds per molecule, and

(F) a polyglycidol derivative into a cell assembly having a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes that is composed primarily of a fluoropolymer;

then

(b) forming a semi-interpenetrating polymer network structure in which molecular chains on the component F polymer are interlocked with a three-dimensional polymer network structure obtained by crosslinking the component C compound.