Dispersant for power storage device positive electrode

Patent metadata

Field	Value
Publication number	US-11891502-B2
Application number	US-201917602580-A
Country	US
Kind code	B2
Filing date	Dec 27, 2019
Priority date	Apr 12, 2019
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

The present invention relates to a dispersant for a positive electrode of a power storage device. The dispersant is a copolymer that contains a constitutional unit A represented by the following general formula (1) and at least one constitutional unit B selected from the group consisting of a constitutional unit B1 represented by the following general formula (2) and a constitutional unit B2 represented by the following general formula (3). The total content of the constitutional unit A and the constitutional unit B in the copolymer is 80% by mass or more. The content of the constitutional unit A in all constitutional units of the copolymer is 35% by mass or more.

First claim

The invention claimed is:

1. A dispersant for a positive electrode of a power storage device, comprising a copolymer that contains a constitutional unit A represented by the following general formula (1) and at least one constitutional unit B selected from the group consisting of a constitutional unit B 1 represented by the following general formula (2) and a constitutional unit B 2 represented by the following general formula (3),
wherein a total content of the constitutional unit A and the constitutional unit B in the copolymer is 80% by mass or more, and the content of the constitutional unit A in all constitutional units of the copolymer is 35% by mass or more:

where R 1 , R 2 , R 3 , R 5 , R 6 , R 7 , R 10 , R 11 , and R 12 are the same or different and represent a hydrogen atom, a methyl group, or an ethyl group, X 1 represents an oxygen atom or NH, R4 represents a hydrocarbon group having 16 to 30 carbon atoms, X 2 represents an oxygen atom, R 8 represents a linear or branched alkylene group having 2 to 4 carbon atoms, p represents 1, R 9 represents a hydrogen atom or a methyl group, and X 3 represents a pyridinyl group that may have a hydrocarbon group having 1 to 4 carbon atoms,
wherein the constitutional unit B is a combination of the constitutional unit B 1 and the constitutional unit B 2 , or the constitutional unit B 2 alone.

2. The dispersant for a positive electrode of a power storage device according to claim 1 , wherein a ratio of the content of the constitutional unit B to the content of the constitutional unit A (constitutional unit B/constitutional unit A) of the copolymer is 0.2 or more and 1.9 or less.

3. The dispersant for a positive electrode of a power storage device according to claim 1 , wherein the content of the constitutional unit A in all the constitutional units of the copolymer is 80% by mass or less.

4. The dispersant for a positive electrode of a power storage device according to claim 1 , wherein the content of the constitutional unit B in all the constitutional units of the copolymer is 5% by mass or more and 65% by mass or less.

5. The dispersant for a positive electrode of a power storage device according to claim 1 , wherein the copolymer further contains a constitutional unit C represented by the following general formula (4):

where R 13 , R 14 , and R 15 are the same or different and represent a hydrogen atom, a methyl group, or an ethyl group, R 16 represents a linear or branched alkylene group having 2 to 4 carbon atoms, X 4 represents an oxygen atom, q represents 2 or more, and R 17 represents a hydrogen atom or a hydrocarbon group.

6. The dispersant for a positive electrode of a power storage device according to claim 1 , wherein a weight average molecular weight of the copolymer is 1,000 or more and 500,000 or less.

7. The dispersant for a positive electrode of a power storage device according to claim 1 , wherein the constitutional unit B is a constitutional unit derived from at least one selected from the group consisting of 2-hydroxyethyl methacrylate, methoxyethyl methacrylate, and 4-vinylpyridine.

8. A conductive material slurry for a battery, comprising conductive materials, the dispersant for a positive electrode of a power storage device according to claim 1 , and a solvent.

9. The conductive material slurry for a battery according to claim 8 , wherein the conductive materials include carbon nanotubes.

10. The conductive material slurry for a battery according to claim 8 , wherein the conductive materials include acetylene black.

11. A method for producing a positive electrode paste for a battery,
the method comprising:
mixing the conductive material slurry for a battery according to claim 8 and a positive electrode active material.

12. A positive electrode paste for a battery, comprising a positive electrode active material, conductive materials, the dispersant for a positive electrode of a power storage device according to claim 1 , and a solvent.

13. The positive electrode paste for a battery according to claim 12 , wherein the solvent is N-methyl-2-pyrrolidone.

14. A positive electrode for a battery, comprising the dispersant for a positive electrode of a power storage device according to claim 1 .

15. The dispersant for a positive electrode of a power storage device according to claim 1 , wherein the constitutional unit B is a combination of the constitutional unit B 1 and the constitutional unit B 2 , or a constitutional unit derived from 4-vinylpyridine alone.

Assignees

• Kao Corp

Inventors

• Kinoshita Yutaro
• Itoi Akito
• Hiraishi Atsushi
• Yano Takahiro
• Koyama Akihiro

Classifications

• C08L33/10 Primary

  Homopolymers or copolymers of methacrylic acid esters · CPC title

• C08L33/26

  Homopolymers or copolymers of acrylamide or methacrylamide · CPC title

• C08L39/08

  Homopolymers or copolymers of vinyl-pyridine · CPC title

• H01B1/24

  the conductive material comprising carbon-silicon compounds, carbon or silicon · CPC title

• H01M4/0416

  involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence) · CPC title