Electrode binder composition for lithium ion electrical storage devices

Patent metadata

Field	Value
Publication number	US-10033043-B2
Application number	US-201615196185-A
Country	US
Kind code	B2
Filing date	Jun 29, 2016
Priority date	Apr 1, 2014
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

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. An electrode slurry comprising:
(a) an electrically active material capable of lithium intercalation/deintercalation,
(b) a binder comprising a dispersion of:
(i) a polyvinylidene fluoride polymer dispersed in an organic dispersion medium with
(ii) a (meth)acrylic polymer dispersant, and

(c) a conductive agent.

2. The electrode slurry of claim 1 in which (a) comprises LiCoO 2 , LiNiO 2 , LiFePO 4 , LiCoPO 4 , LiMnO 2 , LiMn 2 O 4 , Li(NiMnCo)O 2 , Li(NiCoAl)O 2 , carbon-coated LiFePO 4 , or mixtures thereof.

3. The electrode slurry of claim 1 in which (a) is LiFePO 4 .

4. The electrode slurry of claim 1 in which (c) comprises graphite, activated carbon, acetylene black, furnace black or graphene.

5. The electrode slurry of claim 1 in which (a) is present in amounts of 45 to 96 percent by weight; (b) is present in amounts of 2 to 20 percent by weight; and (c) is present in amounts of 2 to 20 percent by weight; the percentages by weight being based on total solids weight.

6. The electrode slurry of claim 1 in which the (meth)acrylic polymer has a glass transition temperature less than 100° C.

7. The electrode slurry of claim 1 in which the (meth)acrylic polymer has a glass transition temperature of −50 to +70° C.

8. The electrode slurry of claim 1 in which the (meth)acrylic polymer is prepared from a mixture of monomers comprising one or more active hydrogen group-containing (meth)acrylic monomers.

9. The electrode slurry of claim 8 in which the active hydrogen groups comprise carboxylic acid groups.

10. The electrode slurry of claim 9 in which the active hydrogen groups additionally comprise hydroxyl groups.

11. The electrode slurry of claim 8 in which the (meth)acrylic polymer is self crosslinking in that the mixture of monomers contains a monomer that contains reactive groups that are reactive with the active hydrogen groups or with themselves.

12. The electrode slurry of claim 11 in which the reactive groups comprise N-alkoxymethyl (meth)acrylamide groups and/or blocked isocyanate groups.

13. The electrode slurry of claim 8 which additionally contains a separately added crosslinking agent reactive with the active hydrogen groups.

14. The electrode slurry of claim 13 in which the crosslinking agent comprises aminoplast, blocked polyisocyanates and/or polyepoxides.

15. The electrode slurry of claim 13 in which 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 crosslinking agent is present in amounts of 1 to 15 percent by weight, the percentages by weight being based on resin solids.

16. The electrode slurry of claim 1 in which the organic dispersion medium comprises ketones, esters and ethers, including mixtures thereof.

17. The electrode slurry of claim 1 in which the organic dispersion medium is present in an amount of 30 to 90 percent by weight, based on the total weight of the electrode slurry.

18. The electrode slurry of claim 1 in which the binder is present in an amount of 2 to 20 percent by weight solids, based on total solids weight of the electrode slurry.

19. The electrode slurry of claim 1 in which the organic dispersion medium is free of N-methyl-3-pyrrolidone.

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, (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 aluminum sheet or foil.

22. The electrode of claim 20 in which the crosslinked (meth)acrylic polymer is formed from reacting active hydrogen groups associated with the (meth)acrylic polymer and a crosslinking agent reactive with the active hydrogen groups.

23. The electrode of claim 22 in which the active hydrogen groups comprise carboxylic acid groups.

24. The electrode of claim 23 in which the active hydrogen groups additionally comprise hydroxyl groups.

25. The electrode of claim 22 in which the crosslinking agent contains a reactive group in the (meth)acrylic polymer or in the separately added crosslinking material that are reactive with the active hydrogen groups.

26. The electrode of claim 25 in which the reactive group comprises N-alkoxymethyl amide groups and/or blocked isocyanate groups.

27. The electrode of claim 25 in which the separately added material comprises aminoplast, blocked polyisocyanates and/or polyepoxides.

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

29. 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(NiCoAl)O 2 , carbon-coated LiFePO 4 , or mixtures thereof.

30. 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.

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

32. The electrical storage device of claim 31 in which the electrolyte is a lithium salt dissolved in a solvent.

33. The electrical storage device of claim 32 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

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M10/056

  characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M10/0525

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

• C09D127/16 Primary

  Homopolymers or copolymers of vinylidene fluoride · CPC title