Electrode binder composition for lithium ion electrical storage devices

Patent metadata

Field	Value
Publication number	US-11817586-B2
Application number	US-202117200702-A
Country	US
Kind code	B2
Filing date	Mar 12, 2021
Priority date	Apr 1, 2014
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

An electrode binder of a lithium ion battery comprising:(a) a polyvinylidene binder dispersed in an organic diluent with(b) a (meth)acrylic polymer dispersant.The binder can be used in the assembly of electrodes of lithium ion batteries.

First claim

The invention claimed is:

1. A binder composition comprising a dispersion of:
(a) a polyvinylidene fluoride polymer dispersed in an organic dispersion medium with
(b) a (meth)acrylic polymer dispersant prepared from a mixture of monomers comprising 2 to 50 percent by weight of alpha, beta-ethylenically unsaturated carboxylic acid, the percent by weight based on total monomer weight; and
(c) a separately added crosslinking agent.

2. The binder composition of claim 1 in which the (meth)acrylic polymer dispersant has a glass transition temperature of −50 to +70° C.

3. The binder composition of claim 1 in which the (meth)acrylic polymer dispersant has a glass transition temperature less than 0° C.

4. The binder composition of claim 1 in which the mixture of monomers further comprises a monomer that contains reactive groups that are reactive with the carboxylic acid groups or are reactive with themselves.

5. The binder composition of claim 4 in which the reactive groups comprise N-alkoxymethyl (meth)acrylamide groups and/or blocked isocyanate groups.

6. The binder composition of claim 1 in which the separately added crosslinking agent comprises an aminoplast resin, a blocked polyisocyanate, and/or a polyepoxide.

7. The binder composition of claim 1 in which the mixture of monomers further comprises a hydroxyalkyl ester of (meth)acrylic acid.

8. The binder composition of claim 7 , wherein the mixture of monomers further comprises 30 to 96% by weight of an alkyl ester of (meth)acrylic acid containing from 1 to 3 carbon atoms in the alkyl group; and up to 30% by weight of the hydroxyalkyl ester of (meth)acrylic acid.

9. The binder composition of claim 1 in which the polyvinylidene fluoride polymer is present in amounts of 50 to 98 percent by weight; the (meth)acrylic polymer dispersant is present in amounts of 2 to 50 percent by weight, and the separately added crosslinking agent is present in amounts of 1 to 15 percent by weight, the percentages by weight being based on resin solids.

10. The binder composition of claim 1 in which the organic dispersing medium comprises ketones, esters, or ethers, including mixtures thereof.

11. The binder composition of claim 1 which has a resin solids content of 30 to 80 percent by weight, based on the total weight of the binder composition.

12. The binder composition of claim 1 in which the organic dispersion medium is free of N-methyl-2-pyrrolidone.

13. An electrode slurry comprising:
(a) an electrically active material capable of lithium intercalation/deintercalation, and
(b) binder composition of claim 1 .

14. The electrode slurry of claim 13 in which (a) comprises LiCoO 2 , LiNiO 2 , LiFePO 4 , LiCoPO 4 , LiMnO 2 , LiMn 2 O 4 , Li(NiMnCo)O 2 , Li(NiCoAI)O 2 , carbon-coated LiFePO 4 , or mixtures thereof.

15. The electrode slurry of claim 13 , further comprising (c) a conductive agent.

16. The electrode slurry of claim 15 in which (c) comprises graphite, activated carbon, acetylene black, furnace black or graphene.

17. The electrode slurry of claim 13 , wherein the binder composition further comprises a separately added crosslinking agent, and the polyvinylidene fluoride polymer is present in amounts of 50 to 98 percent by weight, the (meth)acrylic polymer is present in amounts of 2 to 50 percent by weight and the separately added crosslinking agent is present in amounts of 1 to 15 percent by weight, the percentages by weight being based on resin solids.

18. The electrode slurry of claim 13 in which the organic dispersion medium comprises ketones, esters, or ethers, including mixtures thereof.

19. An electrode slurry comprising:
(a) a conductive agent, and
(b) the binder composition of claim 1 .

20. An electrode comprising:
(a) an electrical current collector;
(b) a cured film formed on the collector (a) comprising:
(i) a polyvinylidene fluoride polymer,
(ii) a crosslinked (meth)acrylic polymer dispersant prepared from a mixture of monomers comprising 2 to 50 percent by weight of alpha, beta-ethylenically unsaturated carboxylic acid, the percent by weight based on total monomer weight, wherein the crosslinked (meth)acrylic polymer dispersant is crosslinked with a separately added crosslinking agent,
(iii) a conductive material, and
(iv) an electrode active material capable of lithium intercalation/deintercalation.

21. The electrode of claim 20 in which (a) comprises copper or an aluminum sheet or foil.

22. The electrode of claim 20 in which the separately added crosslinking agent comprises an aminoplast resin, a blocked polyisocyanate, and/or a polyepoxide.

23. The electrode of claim 20 in which (iii) comprises graphite, activated carbon, acetylene black, furnace black, or graphene.

24. The electrode of claim 20 in which (iv) comprises LiCoO 2 , LiNiO 2 , LiFePO 4 , LiCoPO 4 , LiMnO 2 , LiMn 2 O 4 , Li(NiMnCo)O 2 , Li(NiCoAI)O 2 , carbon-coated LiFePO 4 , or mixtures thereof.

25. The electrode of claim 20 in which (i) is present in amounts of 1 to 20 percent by weight; (ii) is present in amounts of 0.1 to 10 percent by weight; (iii) is present in amounts of 2 to 20 percent by weight; and (iv) is present in amounts of 45 to 96 percent by weight, the percentages by weight being based on total weight of the mixture and the weight ratio of (i) to (ii) is greater than or equal to 1.

26. An electrical storage device comprising:
(a) the electrode of claim 20 ,
(b) a counter electrode, and
(c) an electrolyte.

27. The electrical storage device of claim 26 in which the electrolyte is a lithium salt dissolved in a solvent.

28. The electrical storage device of claim 27 in which the lithium salt is dissolved in an organic carbonate.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Hellring Stuart D
• Daughenbaugh Randy E
• Swarup Shanti
• Van Buskirk Ellor James

Classifications

• H01M4/623 Primary

  fluorinated polymers · CPC title

• C09D127/16 Primary

  Homopolymers or copolymers of vinylidene fluoride · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/0409

  by a doctor blade method, slip-casting or roller coating · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title