Composition for electrochemical device, electrode and secondary battery

Patent metadata

Field	Value
Publication number	US-2024372103-A1
Application number	US-202418772398-A
Country	US
Kind code	A1
Filing date	Jul 15, 2024
Priority date	Jan 17, 2022
Publication date	Nov 7, 2024
Grant date	—

Abstract

Provided is a composition for an electrochemical device, containing a single-walled carbon nanotube, a binder, and a solvent, wherein the binder comprises a fluorine-containing copolymer comprising a repeating unit (a) based on vinylidene fluoride, and at least one repeating unit (b) selected from the group consisting of a repeating unit (b1) and a repeating unit (b2).

First claim

1 . A composition for an electrochemical device, comprising a single-walled carbon nanotube, a binder, and a solvent,
wherein the binder comprises a fluorine-containing copolymer comprising a repeating unit (a) based on vinylidene fluoride, and at least one repeating unit (b) selected from the group consisting of a repeating unit (b1) represented by a general formula (b1) and a repeating unit (b2) represented by a general formula (b2):

wherein Rf 1 is a linear or branched fluorinated alkyl group or fluorinated alkoxy group having 1 to 12 carbon atoms, and when the number of carbon atoms is 2 or more, Rf 1 optionally comprises oxygen atom between carbon atoms,

wherein Rf 2 is a linear or branched fluorinated alkyl group or fluorinated alkoxy group having 1 to 12 carbon atoms, and when the number of carbon atoms is 2 or more, Rf 2 optionally comprises oxygen atom between carbon atoms.

2 . The composition for an electrochemical device according to claim 1 , wherein an average outer diameter of the single-walled carbon nanotube is 2.5 nm or less.

3 . The composition for an electrochemical device according to claim 1 , wherein an average G/D ratio of the single-walled carbon nanotube is 2 or more.

4 . The composition for an electrochemical device according to claim 1 , wherein in the fluorine-containing copolymer, a molar ratio of the repeating unit (a) to the repeating unit (b), (a)/(b), is 99/1 to 20/80.

5 . The composition for an electrochemical device according to claim 1 , wherein a glass transition temperature of the fluorine-containing copolymer is 25° C. or less.

6 . The composition for an electrochemical device according to claim 1 , wherein the binder further comprises a polyvinylidene fluoride.

7 . The composition for an electrochemical device according to claim 6 , wherein a mass ratio of the fluorine-containing copolymer to the polyvinylidene fluoride, fluorine-containing copolymer/polyvinylidene fluoride, is 99/1 to 1/99.

8 . The composition for an electrochemical device according to claim 1 , wherein the solvent is water or at least one selected from the group consisting of N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and a solvent represented by a general formula (1):

wherein R 1 , R 2 , and R 3 are each independently H or a monovalent substituent, provided that the total number of carbon atoms of R 1 , R 2 , and R 3 is 6 or more, and at least one of R 1 , R 2 , and R 3 is an organic group having carbonyl group; and any two of R 1 , R 2 , and R 3 optionally bond to each other to form a ring.

9 . The composition for an electrochemical device according to claim 1 , wherein the composition for an electrochemical device is used to form an electrode of an electrochemical device.

10 . The composition for an electrochemical device according to claim 1 , further comprising a powder electrode material, excluding the single-walled carbon nanotube.

11 . The composition for an electrochemical device according to claim 10 , wherein the powder electrode material comprises a lithium composite oxide as a positive electrode active material.

12 . The composition for an electrochemical device according to claim 11 , wherein a content of the single-walled carbon nanotube is 0.001 to 10 parts by mass per 100 parts by mass of the positive electrode active material.

13 . The composition for an electrochemical device according to claim 11 , wherein a content of the binder is 0.01 to 5.0 parts by mass per 100 parts by mass of the positive electrode active material.

14 . The composition for an electrochemical device according to claim 10 , wherein the powder electrode material comprises a negative electrode active material that exhibits a potential of 2.5 V or less vs. Li when alloyed with Li or bonded with Li.

15 . The composition for an electrochemical device according to claim 14 , wherein a content of the single-walled carbon nanotube is 0.001 to 10 parts by mass per 100 parts by mass of the negative electrode active material.

16 . The composition for an electrochemical device according to claim 14 , wherein a content of the binder is 0.01 to 20.0 parts by mass per 100 parts by mass of the negative electrode active material.

17 . An electrode comprising a current collector and an electrode material layer provided on one side or each of both sides of the current collector and formed from the composition for an electrochemical device according to claim 1 .

18 . A secondary battery comprising the electrode according to claim 17 .

Assignees

• Daikin Ind Ltd
• Mcd Tech S A R L

Inventors

• Ichinose Yuma
• Terada Junpei
• Yamazaki Shigeaki
• Shimooka Toshiharu
• Hosoda Chihiro
• Furutani Takahiro
• Predtechenskiy Mikhail Rudolfovich
• Bobrenok Oleg Filippovich

Classifications

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title