Composition for secondary battery electrode

Patent metadata

Field	Value
Publication number	US-11239467-B2
Application number	US-201816647905-A
Country	US
Kind code	B2
Filing date	Sep 27, 2018
Priority date	Sep 28, 2017
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

The present invention aims to provide a composition for a secondary battery electrode which is excellent in dispersibility of an active material and adhesiveness, capable of preventing battery deterioration and failure due to moisture absorption, and capable of providing a high-capacity secondary battery. Provided is a composition for a secondary battery electrode, containing: an active material; a binder; and an organic solvent, the binder containing a polyvinyl acetal resin, the polyvinyl acetal resin having an electron-donating group that has an acid dissociation constant in water of less than 16 and an electron-withdrawing group, the polyvinyl acetal resin having a degree of polymerization of 250 to 800 and a hydroxy group content of 35 to 70 mol %.

First claim

The invention claimed is:

1. A composition for a secondary battery electrode, comprising:
an active material;
a binder; and
an organic solvent,
the binder containing a polyvinyl acetal resin,
the polyvinyl acetal resin having an electron-donating group that has an acid dissociation constant in water of less than 16 and an electron-withdrawing group,
the polyvinyl acetal resin having a degree of polymerization of 250 to 800 and a hydroxy group content of 35 to 70 mol %, and
the electron-withdrawing group being bonded directly to a carbon constituting a main chain, or being bonded to an acetal group of the polyvinyl acetal resin.

2. The composition for a secondary battery electrode according to claim 1 ,
wherein the electron-donating group is a functional group having a lactam structure.

3. The composition for a secondary battery electrode according to claim 2 ,
wherein the lactam structure is at least one cyclic structure selected from the group consisting of a 3-membered ring, a 4-membered ring, a 5-membered ring, and a 6-membered ring.

4. The composition for a secondary battery electrode according to claim 2 ,
wherein the lactam structure is a structure represented by the following formula (1):

wherein n is an integer of 1 to 5 and R 0 is a single bond or a C1-C10 saturated or unsaturated hydrocarbon.

5. The composition for a secondary battery electrode according to claim 3 ,
wherein a hydrocarbon constituting the cyclic structure of the lactam structure is unsubstituted, or a hydrogen atom of the hydrocarbon is substituted with a C1-C10 saturated or unsaturated hydrocarbon.

6. The composition for a secondary battery electrode according to claim 1 ,
wherein in the polyvinyl acetal resin, the amount of a structural unit having the electron-donating group is 0.01 to 10 mol %.

7. The composition for a secondary battery electrode according to claim 1 ,
wherein the electron-withdrawing group is a carboxy group.

8. The composition for a secondary battery electrode according to claim 1 ,
wherein in the polyvinyl acetal resin, the amount of a structural unit having the electron-withdrawing group is 0.01 to 10 mol %.

9. The composition for a secondary battery electrode according to claim 1 ,
wherein the polyvinyl acetal resin has a degree of acetalization of 20 to 70 mol %.

10. The composition for a secondary battery electrode according to claim 1 ,
wherein the polyvinyl acetal resin has a structural unit having the acetyl group and the acetyl group content is 15 mol % or less.

11. The composition for a secondary battery electrode according to claim 1 , containing 0.01 to 20 parts by weight of the polyvinyl acetal resin relative to 100 parts by weight of the active material.

12. The composition for a secondary battery electrode according to claim 1 , further comprising a polyvinylidene fluoride resin.

13. A secondary battery comprising
the composition for a secondary battery electrode according to claim 1 .

14. The composition for a secondary battery electrode according to claim 1 ,
wherein the electron-donating group is at least one functional group selected from the group consisting of an amino group, an alkylamino group, —S—, and a functional group having a lactam structure.

15. The composition for a secondary battery electrode according to claim 1 ,
wherein the electron-withdrawing group is at least one functional group selected from the group consisting of an acidic group, a nitro group, a sulfo group, a sulfonyl group, a sulfinyl group, a formyl group, a fluorinated alkyl group and a halogen.

Assignees

• Sekisui Chemical Co Ltd

Inventors

• Asaba Yuutarou

Classifications

• H01M4/622 Primary

  being polymers · CPC title

• C08F216/38 Primary

  by an acetal or ketal radical · CPC title

• H01M4/362

  Composites · CPC title

• C08F116/38

  by a acetal or ketal radical · CPC title

• C08F216/06

  Polyvinyl alcohol {; Vinyl alcohol} · CPC title