Binder for battery electrode, and electrode and battery using same

Patent metadata

Field	Value
Publication number	US-10014525-B2
Application number	US-201414762982-A
Country	US
Kind code	B2
Filing date	Jan 24, 2014
Priority date	Jan 29, 2013
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

This binder for battery electrodes is characterized by containing a polymer including: (A) a structural unit represented by general formula (1) and derived from a monomer having a hydroxyl group

(in the formula, R1 is a hydrogen or a C1-C4 straight-chain or branched alkyl group, R2 and R3 are each a hydrogen or a C1-C4 straight-chained or branched alkyl group, and n is an integer of 2-30); (B) a structural unit derived from an ethylenically unsaturated monomer having at least one functional group selected from the group consisting of a difunctional carboxylic acid group, a nitrile group and a ketone group; and (C) a structural unit derived from a polyfunctional (meth)acrylate monomer having at most five functional groups.

First claim

The invention claimed is:

1. A binder for battery electrode, comprising a polymer comprising:
1 to 89.9% by weight of (A) constitutional units derived from a monomer having a hydroxyl group, of the formula (1):

wherein R 1 is hydrogen, or a linear or branched alkyl group having 1 to 4 carbon atoms,
R 2 and R 3 each is hydrogen, or a linear or branched alkyl group having 1 to 4 carbon atoms, and
n is an integer of 2 to 30,
40 to 10% by weight of (B) constitutional units derived from an ethylenically unsaturated monomer having at least one functional group selected from the group consisting of a difunctional carboxylic acid group, a nitrile group and a ketone group, and
20 to 0.1% by weight of (C) constitutional units derived from a polyfunctional (meth)acrylate monomer having penta- or less functionality.

2. The binder for battery electrode according to claim 1 , wherein n is an integer of 4 to 20, in the formula (1).

3. The binder for battery electrode according to claim 1 , wherein the functional group-containing ethylenically unsaturated monomer (B) is a compound of the formula (2):
(A 1 -)(A 2 -)C═C(-A 3 )(-A 4 )  (2)

wherein A 1 is a group having a nitrile group (—CN group), a carboxylic acid group (—COOH group) or a ketone group (>C═O group),
A 2 and A 3 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1-6 carbon atoms, or a group having a nitrile group (—CN group) or a carboxylic acid group (—COOH group),
A 4 is a hydrogen atom, a halogen atom, or an alkyl group having 1-6 carbon atoms, and
A 1 and A 2 , or A 1 and A 3 may be joined together to form a cyclic hydrocarbon group having two carboxylic acid groups.

4. The binder for battery electrode according to claim 1 , wherein the group having a nitrile group (—CN group) is a —B—CN group wherein B 2 is a direct bond or an alkylene group having 1-6 carbon atoms,
the group having a difunctional carboxylic acid group (—COOH group) (dicarboxylic acid group) is a —B 1 —COOH group wherein B 1 is a direct bond or an alkylene group having 1-6 carbon atoms, and
the group having a ketone group (>C═O group) is a —B 3 —CO—B 4 group wherein B 3 is a direct bond or an alkylene group having 1-6 carbon atoms, and B 4 is an alkyl group having 1-6 carbon atoms.

5. The binder for battery electrode according to claim 1 , wherein the ethylenically unsaturated monomer having a nitrile group (—CN group) is a compound of the formula:
(CN—)(X 11 —)C═C(—X 12 )(—X 13 )

wherein X 11 is a hydrogen atom, an alkyl group having 1-6 carbon atoms, a halogen atom or a cyano group,
X 12 is a hydrogen atom, an alkyl group having 1-6 carbon atoms or a cyano group, and
X 13 is a hydrogen atom, an alkyl group having 1-6 carbon atoms or a halogen atom.

6. The binder for battery electrode according to claim 1 , wherein the ethylenically unsaturated monomer having a difunctional carboxylic acid group is a compound of the formula:
(HOOC—X 21 —)(HOOC—X 22 —) m (—X 23 ) 1-m C═C(—X 22 —COOH) 1-m (—X 23 ) m (—X 24 )

wherein X 21 and X 22 are each independently a direct bond or an alkylene group having 1-6 carbon atoms,
X 23 and X 24 are each independently a hydrogen atom, an alkyl group having 1-6 carbon atoms or a halogen atom, and
m is 0 or 1.

7. The binder for battery electrode according to claim 1 , wherein the ethylenically unsaturated monomer having a ketone group is a compound of the formula:
(X 31 —CO—X 32 —)(X 33 —)C═C(—X 34 )(—X 35 )

wherein X 31 , X 33 , X 34 and X 35 are each independently a hydrogen atom, an alkyl group having 1-6 carbon atoms or a halogen atom, and
X 32 is a direct bond or an alkylene group having 1-6 carbon atoms.

8. The binder for battery electrode according to claim 1 , wherein the polyfunctional (meth)acrylate monomer (C) is a compound of the formula (3):

wherein R 11 is independently hydrogen or a methyl group,
R 12 is a penta- or less valent organic group having 2 to 100 carbon atoms, and
m is an integer less than or equal to 5.

9. The binder for battery electrode according to claim 1 , wherein the polyfunctional (meth)acrylate (C) is a (meth)acrylate having tri-functionality to penta-functionality.

10. The binder for battery electrodes according to claim 1 , wherein the polymer further comprises one or both of constitutional units (D) derived from a (meth)acrylate ester monomer and constitutional units (E) derived from a (meth)acrylic acid monomer.

11. The binder for battery electrode according to claim 10 , wherein the (meth)acrylate ester monomer (D) is a compound of the formula (4):

wherein R 21 is hydrogen or a methyl group, and
R 22 is a hydrocarbon group having 1 to 50 carbon atoms.

12. The binder for battery electrode according to claim 10 , wherein the (meth)acrylic acid monomer (E) is a compound of the formula (5):

wherein R 31 is hydrogen or a methyl group.

13. The binder for battery electrode according to claim 1 , wherein the battery is a secondary battery.

14. A battery electrode comprising the binder according to claim 1 , and an active material.

15. A battery comprising the electrode according to claim 14 .

Assignees

• Osaka Soda Co Ltd

Inventors

• Matsuo Takashi
• Yano Tomoyuki
• Miki Yasushi
• Miura Katsuhito

Classifications

• H01M4/622 Primary

  being polymers · CPC title

• C08F290/062 Primary

  Polyethers · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• C08F222/30

  Nitriles · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title