Granted Patent B2

US 8,372,474 · App. 11/374,651 · Granted Feb 12, 2013

Inventors: Bhaskar Sompalli (Rochester, NY); Chunxin Ji (Pennfield, NY); Susan G. Yan (Fairport, NY); Hubert A. Gasteiger (Rochester, NY); Hiroshi Shimoda (Tokyo, JP); Shinji Terazono (Yokohama, JP); Hirokazu Wakabayashi (Yokohama, JP); Atsuo Okawara (Yokohama, JP); Kohta Yamada (Yokohama, JP); Seigo Kotera (Yokohama, JP); Shinji Kinoshita (Yokohama, JP); Toshihiro Tanuma (Yokohama, JP)

Assignee: GM Global Technology Operations LLC

Abstract

Claims (61)

1. A process comprising:

providing a substrate and coating the substrate with a surface treatment to improve catalyst layer transfer;

applying a layer comprising a catalyst to the surface treated substrate;

depositing a first ionomer overcoat layer over the layer comprising the catalyst, the first ionomer overcoat layer comprising an ionomer and a first solvent;

drying the first ionomer overcoat layer to provide a first electrode ionomer overcoat layer; and

depositing a second ionomer overcoat layer over the first electrode ionomer overcoat layer, and wherein the second ionomer overcoat layer comprises an ionomer and a second solvent.

2. A process as set forth in claim 1 further comprising depositing a second ionomer overcoat layer over the first electrode ionomer overcoat layer, and wherein the second ionomer overcoat layer comprises an ionomer and a second solvent and drying the second ionomer overcoat layer to provide a second electrode ionomer overcoat layer.

3. A process as set forth in claim 2 wherein the first solvent and second solvent are the same.

4. A method as set forth in claim 2 wherein the second solvent is less wetting than the first solvent.

5. A process as set forth in claim 2 wherein the first solvent comprises a wetting solvent, and wherein the second solvent comprises a less-wetting or non-wetting solvent.

6. A process as set forth in claim 1 wherein the first solvent comprises methanol, a C 2 or higher alcohol.

7. A process as set forth in claim 1 wherein the first solvent comprises at least one of methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol or mixtures thereof.

8. A process as set forth in claim 2 wherein the second solvent comprises at least one of water or a glycol.

9. A process as set forth in claim 2 wherein the second solvent comprises at least one of water or a glycol; and wherein the second solvent further comprises at least one of methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol or mixtures thereof.

10. A process as set forth in claim 2 , further comprising depositing a third ionomer overcoat layer on the second electrode ionomer overcoat layer, the third ionomer overcoat layer comprising an ionomer and a third solvent.

11. A process as set forth in claim 10 wherein the third solvent is the same as the first solvent and the second solvent.

12. A process as set forth in claim 10 wherein the third solvent is less wetting than the second solvent.

13. A process as set forth in claim 10 wherein the third solvent is a non-wetting solvent.

14. A process as set forth in claim 10 wherein the third solvent comprises methanol, a C 2 or higher alcohol.

15. A process as set forth in claim 1 wherein the second solvent comprises methanol, C 2 or higher alcohol.

16. A process as set forth in claim 10 wherein the third solvent comprises at least one of methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol or mixtures thereof.

17. A process as set forth in claim 1 wherein the second solvent comprises at least one of methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol or mixtures thereof.

18. A process as set forth in claim 10 wherein the third solvent comprises at least one of water or a glycol.

19. A process as set forth in claim 10 wherein the third solvent comprises at least one of water or a glycol; and wherein the third solvent further comprises at least one of methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol or mixtures thereof.

20. A process as set forth in claim 10 further comprising drying the third ionomer overcoat layer to produce a third electrode ionomer overcoat layer.

21. A process as set forth in claim 20 , further comprising depositing a fourth ionomer overcoat layer on the third electrode ionomer overcoat layer, the fourth ionomer overcoat layer comprising an ionomer and a fourth solvent.

22. A process as set forth in claim 20 wherein the fourth solvent is the same as the first solvent and the third solvent.

23. A process as set forth in claim 20 wherein the fourth solvent is less wetting than the third solvent.

24. A process as set forth in claim 20 wherein the fourth solvent is a non-wetting solvent.

25. A process as set forth in claim 20 wherein the fourth solvent comprises methanol, a C 2 or higher alcohol.

26. A process as set forth in claim 20 wherein the fourth solvent comprises at least one of methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol or mixtures thereof.

27. A process as set forth in claim 20 wherein the fourth solvent comprises at least one of water or a glycol.

28. A process as set forth in claim 20 wherein the fourth solvent comprises at least one of water or a glycol; and wherein the third solvent further comprises at least one of methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol or mixtures thereof.

29. A process as set forth in claim 20 further comprising drying the fourth ionomer overcoat layer to produce a fourth electrode ionomer overcoat layer.

30. A process as set forth in claim 1 wherein the substrate comprises a porous decal support.

31. A process as set forth in claim 1 wherein the substrate comprises a non-porous substrate.

32. A process as set forth in claim 1 wherein the substrate comprises polytetrafluoroethylene.

33. A process as set forth in claim 1 wherein the substrate comprises expanded polytetrafluoroethylene.

34. A process as set forth in claim 1 wherein the substrate comprises PET.

35. A process as set forth in claim 1 wherein the substrate comprises a gas diffusion media material and a microporous layer on the gas diffusion media layer, and wherein the ionomer overcoat layers are applied onto electrodes supported on the microporous layer.

36. A process as set forth in claim 1 wherein the substrate comprises a porous decal and a carrier film.

37. A process as set forth in claim 1 wherein the substrate comprises at least one of porous expanded PTFE, porous polypropylene, porous polyethylene, or other porous substrates.

38. A process as set forth in claim 1 wherein the substrate is porous having pores less than 1 micron.

39. A process as set forth in claim 1 wherein the substrate is porous having a void volume ranging from 10 to 90 percent.

40. A process as set forth in claim 1 wherein the substrate is porous having a thickness ranging from 10 to 100 microns.

41. A process as set forth in claim 1 wherein the substrate comprises at least one of ethylene tetrafluoroethylene, polyethylene terephthalate, polyethylene naphthalate, or non-porous PTFE.

42. A process as set forth in claim 41 wherein the substrate is surface treated to improve catalyst layer transfer.

43. A process as set forth in claim 1 further comprising surface treating the substrate comprising one of sand-blasting or plasma-etching.

44. A process comprising:

(a) providing a substrate with a layer comprising a catalyst thereon, wherein the substrate comprises a decal;

(b) depositing a first ionomer overcoat layer over the catalyst layer, the first ionomer overcoat layer comprising an ionomer and a first solvent;

(c) drying the first ionomer overcoat layer to provide a first electrode ionomer overcoat layer; and

(d) depositing a second ionomer overcoat layer over the first electrode ionomer overcoat layer, and wherein the second ionomer overcoat layer comprises an ionomer and a second solvent.

45. A process comprising:

providing a substrate and a layer comprising a catalyst thereon;

applying a first ionomer overcoat layer over the layer comprising the catalyst, the first ionomer overcoat layer comprising an ionomer and a first solvent, the first solvent comprising a wetting solvent;

drying the first ionomer overcoat layer to provide a first dried ionomer overcoat layer;

depositing a second ionomer overcoat layer over the first ionomer overcoat layer, and wherein the second ionomer overcoat layer comprises an ionomer and a second solvent, the second solvent comprising a non-wetting solvent; and

drying the second ionomer overcoat layer to provide a second dried ionomer layer over the first dried ionomer overcoat layer.

46. A process as set forth in claim 44 wherein the substrate comprises a gas diffusion media structure.

47. A process as set forth in claim 44 wherein the substrate comprises a gas diffusion media material, and wherein ionomer overcoat layers are applied onto electrodes supported on the gas diffusion media material.

Assignments (13)

Continuity (1)