Battery electrode coatings applied by waterborne electrodeposition

Patent metadata

Field	Value
Publication number	US-11469407-B2
Application number	US-201816228176-A
Country	US
Kind code	B2
Filing date	Dec 20, 2018
Priority date	Dec 20, 2018
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

The present invention is directed towards an electrodepositable coating composition comprising (a) a fluoropolymer; (b) an electrochemically active material and/or electrically conductive agent; (c) a pH-dependent rheology modifier; and (d) an aqueous medium comprising water; wherein water is present in an amount of at least 45% by weight, based on the total weight of the electrodepositable coating composition. Also disclosed herein is a method of coating a substrate, as well as coated substrates and electrical storage devices.

First claim

We claim:

1. An electrodepositable coating composition comprising:
(a) a fluoropolymer;
(b) an electrochemically active material and/or electrically conductive agent;
(c) a pH-dependent rheology modifier; and
(d) an aqueous medium comprising water;
wherein water is present in an amount of at least 45% by weight, based on the total weight of the electrodepositable coating composition,
wherein the electrodepositable coating composition has a solids content of no more than 30% by weight, based on the total weight of the electrodepositable coating composition.

2. The electrodepositable coating composition of claim 1 , wherein the fluoropolymer comprises a (co)polymer comprising the residue of vinylidene fluoride.

3. The electrodepositable coating composition of claim 2 , wherein the fluoropolymer comprises a (co)polymer comprising the residue of tetrafluoroethylene.

4. The electrodepositable coating composition of claim 1 , wherein the electrochemically active material comprises LiCoO 2 , LiNiO 2 , LiFePO 4 , LiFeCoPO 4 , LiCoPO 4 , LiMnO 2 , LiMn 2 O 4 , Li(NiMnCo)O 2 , Li(NiCoAl)O 2 , carbon-coated LiFePO 4 , or a combination thereof.

5. The electrodepositable coating composition of claim 1 , wherein the electrochemically active material comprises sulfur, LiO 2 , FeF 2 and FeF 3 , Si, aluminum, tin, SnCo, Fe 3 O 4 , or combinations thereof.

6. The electrodepositable coating composition of claim 1 , wherein the electrochemically active material comprises graphite, lithium titanate, lithium vanadium phosphate, silicon, silicon compounds, tin, tin compounds, sulfur, sulfur compounds, lithium metal, graphene, or a combination thereof.

7. The electrodepositable coating composition of claim 1 , wherein the pH-dependent rheology modifier comprises an alkali-swellable rheology modifier.

8. The electrodepositable coating composition of claim 7 , wherein a composition of water and the alkali-swellable rheology modifier at 4.25% by weight of the total composition of water and the alkali-swellable rheology modifier has an increase in viscosity of at least 500 cps over an increase in pH value of 1 pH unit, as measured using a Brookfield viscometer using a #4 spindle and operated at 20 RPMs.

9. The electrodepositable coating composition of claim 1 , wherein the pH-dependent rheology modifier comprises an acid-swellable rheology modifier.

10. The electrodepositable coating composition of claim 1 , further comprising a dispersant.

11. The electrodepositable coating composition of claim 10 , wherein the dispersant comprises a (meth)acrylic polymer dispersant.

12. The electrodepositable coating composition of claim 10 , further comprising a crosslinking agent.

13. The electrodepositable coating composition of claim 11 , wherein the electrically conductive agent comprises conductive carbon black, carbon nanotubes, graphene, graphite, carbon fibers, fullerenes, and combinations thereof.

14. The electrodepositable coating composition of claim 1 , wherein the electrodepositable coating composition comprises:
(a) 0.1% to 10% by weight of the fluoropolymer;
(b) 45% to 99% by weight of the electrochemically active material;
(c) 0.1% to 10% by weight of the pH-dependent rheology modifier; and
(d) optionally 0.5% to 20% by weight of the electrically conductive agent; the % by weight based on the total solids weight of the electrodepositable composition.

15. The electrodepositable coating composition of claim 1 , wherein the VOC of the electrodepositable coating composition is no more than 300 g/L.

16. The electrodepositable coating composition of claim 1 , wherein the electrodepositable coating composition is substantially free of fugitive adhesion promoter.

17. The electrodepositable coating composition of claim 1 , wherein a coating produced by electrodepositing the electrodepositable coating composition of claim 1 to a substrate has a 90° peel strength at least 20% greater than a comparative coating composition that does not include the pH-dependent rheology modifier, the 90° peel strength measured according to PEEL STRENGTH TEST METHOD.

18. The electrodepositable coating composition of claim 1 , wherein a coating produced by electrodepositing the electrodepositable coating composition of claim 1 to a substrate has a 90° peel strength of at least 5 N/m, as measured according to PEEL STRENGTH TEST METHOD.

19. A method of coating a substrate, the method comprising:
electrocoating the electrodepositable coating composition of claim 1 onto a substrate.

20. The method of claim 19 , wherein the method has a mass deposition rate of the electrodepositable coating composition of at least 0.5 mg/cm 2 /s.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Oakes Landon J
• Hellring Stuart D
• Orler Haley L
• Mohin Jacob W
• Sisco Scott W

Classifications

• H01M4/0452 Primary

  from solutions · CPC title

• H01M4/131

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

• H01G11/38

  Carbon pastes or blends; Binders or additives therein · CPC title

• C25D9/04

  with inorganic materials · CPC title

• C25D13/12

  characterised by the article coated · CPC title