Method of Preparing Cathode Slurry for Secondary Battery

Patent metadata

Field	Value
Publication number	US-2024413337-A1
Application number	US-202418736598-A
Country	US
Kind code	A1
Filing date	Jun 7, 2024
Priority date	Jun 9, 2023
Publication date	Dec 12, 2024
Grant date	—

Abstract

The invention provides a method of preparing a cathode slurry for a secondary battery, comprising a binder material, comprising a copolymer P 1 and a copolymer P 2 . Both copolymers each independently comprise a structural unit derived from a monomer containing an acid group; a structural unit derived from a monomer selected from the group consisting of an amide group-containing monomer, a hydroxyl group-containing monomer, and combinations thereof; and a structural unit derived from a monomer selected from the group consisting of a nitrile group-containing monomer, an ether group-containing monomer, an epoxy group-containing monomer, and combinations thereof. As a result of the chemical compositions of the respective copolymers and the method itself, the cathode slurry is well dispersed, and batteries made therefrom have good cycling stability.

First claim

What is claimed is:

1 . A method of preparing a cathode slurry for a secondary battery, comprising the steps of:
1) dispersing a binder composition A and a cathode active material in an aqueous solvent to form a first mixture; 2) adding a binder composition B into the first mixture to form a second mixture; and 3) homogenizing the second mixture to obtain the cathode slurry; wherein the binder composition A comprises a copolymer P 1 , and the binder composition B comprises a copolymer P 2 ; wherein the copolymer P 1 comprises a structural unit (a 1 ), a structural unit (b 1 ), and a structural unit (c 1 ); wherein the copolymer P 2 comprises a structural unit (a 2 ), a structural unit (b 2 ), and a structural unit (c 2 ); wherein each of the structural unit (a 1 ) and the structural unit (a 2 ) is independently derived from a monomer containing an acid group; wherein each of the structural unit (b 1 ) and the structural unit (b 2 ) is independently derived from a monomer selected from the group consisting of an amide group-containing monomer, a hydroxyl group-containing monomer, and combinations thereof; and wherein each of the structural unit (c 1 ) and the structural unit (c 2 ) is independently derived from a monomer selected from the group consisting of a nitrile group-containing monomer, an ether group-containing monomer, an epoxy group-containing monomer, and combinations thereof.

2 . The method according to claim 1 , wherein the acid group is selected from the group consisting of carboxylic acid, sulfonic acid, sulfuric acid, phosphonic acid, phosphoric acid, nitric acid, their salts, their derivatives, and combinations thereof.

3 . The method according to claim 1 , wherein the chemical compositions of the copolymer P 1 and the copolymer P 2 are different.

4 . The method according to claim 1 , wherein the proportion of the structural unit (a 1 ) in the copolymer P 1 is from about 45% to about 80% by mole, based on the total number of moles of monomeric units in the copolymer P 1 .

5 . The method according to claim 1 , wherein the proportion of the structural unit (a 2 ) in the copolymer P 2 is from about 15% to about 30% by mole, based on the total number of moles of monomeric units in the copolymer P 2 .

6 . The method according to claim 1 , wherein the proportion of the structural unit (b 1 ) in the copolymer P 1 is from about 10% to about 35% by mole, based on the total number of moles of monomeric units in the copolymer P 1 .

7 . The method according to claim 1 , wherein the proportion of the structural unit (b 2 ) in the copolymer P 2 is from about 5% to about 30% by mole, based on the total number of moles of monomeric units in the copolymer P 2 .

8 . The method according to claim 1 , wherein the proportion of the structural unit (c 1 ) in the copolymer P 1 is from about 10% to about 40% by mole, based on the total number of moles of monomeric units in the copolymer P 1 .

9 . The method according to claim 1 , wherein the proportion of the structural unit (c 2 ) in the copolymer P 2 is from about 50% to about 75% by mole, based on the total number of moles of monomeric units in the copolymer P 2 .

10 . The method according to claim 1 , wherein the monomers which the structural unit (a 1 ) and the structural unit (a 2 ) are derived from are different; wherein the monomers which the structural unit (b 1 ) and the structural unit (b 2 ) are derived from are different; and wherein the monomers which the structural unit (c 1 ) and the structural unit (c 2 ) are derived from are different.

11 . The method according to claim 1 , wherein the carboxylic acid is independently selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic acid, 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglic acid, 3,3-dimethyl acrylic acid, 3-propyl acrylic acid, trans-2-methyl-3-ethyl acrylic acid, cis-2-methyl-3-ethyl acrylic acid, 3-isopropyl acrylic acid, trans-3-methyl-3-ethyl acrylic acid, cis-3-methyl-3-ethyl acrylic acid, 2-isopropyl acrylic acid, trimethyl acrylic acid, 2-methyl-3,3-diethyl acrylic acid, 3-butyl acrylic acid, 2-butyl acrylic acid, 2-pentyl acrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-methyl-3-propyl acrylic acid, 2-ethyl-3-propyl acrylic acid, 2,3-diethyl acrylic acid, 3,3-diethyl acrylic acid, 3-methyl-3-hexyl acrylic acid, 3-methyl-3-tert-butyl acrylic acid, 2-methyl-3-pentyl acrylic acid, 3-methyl-3-pentyl acrylic acid, 4-methyl-2-hexenoic acid, 4-ethyl-2-hexenoic acid, 3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butyl acrylic acid, 2,3-dimethyl-3-ethyl acrylic acid, 3,3-dimethyl-2-ethyl acrylic acid, 3-methyl-3-isopropyl acrylic acid, 2-methyl-3-isopropyl acrylic acid, trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, and combinations thereof.

12 . The method according to claim 1 , wherein the amide group-containing monomer is independently selected from the group consisting of acrylamide, methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, N-n-propyl methacrylamide, N-isopropyl methacrylamide, isopropyl acrylamide, N-n-butyl methacrylamide, N-isobutyl methacrylamide, N,N-dimethyl acrylamide, N,N-dimethyl methacrylamide, N,N-diethyl acrylamide, N,N-diethyl methacrylamide, N-methylol methacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, N-(propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethyl methacrylamide, N,N-dimethylol methacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryloyl morpholine, N-hydroxyl methacrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, N,N′-methylene-bis-acrylamide, N-hydroxymethyl acrylamide, and combinations thereof.

13 . The method according to claim 1 , wherein the nitrile group-containing monomer is independently selected from the group consisting of acrylonitrile, α-halogenoacrylonitrile, α-alkylacrylonitrile, α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidene cyanide, and combinations thereof.

14 . The method according to claim 1 , wherein the aqueous solvent is water, and wherein the proportion of water in the non-solid portion of the cathode slurry is more than 50%.

15 . The method according to claim 14 , wherein the aqueous solvent comprises a minor component in addition to water; wherein the minor component is selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, ethylene glycol, propylene glycol, glycerol, acetone, dimethyl ketone, methyl ethyl ketone, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, 1,4-dioxane, diethyl ether, methyl tert-butyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran, acetonitrile, dimethyl sulfoxide, sulfolane, nitromethane, propylene carbonate, ethylene carbonate, dimethyl carbonate, pyridine, acetaldehyde, formic acid, acetic acid, propanoic a

Assignees

• Grst Int Ltd

Inventors

• Ho Kam Piu
• Qiu Hongke

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• C08F220/48

  with nitrogen-containing monomers · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• H01M10/0525

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

• H01M4/36

  Selection of substances as active materials, active masses, active liquids · CPC title