Recharge catalyst with thin film carbon coating, metal-air electrode including said catalyst and methods for making said catalyst and electrode

• US 6,069,107 A
• Filed: 06/17/1998
• Issued: 05/30/2000
• Est. Priority Date: 06/17/1998
• Status: Expired due to Fees

• Current Assignee: Gillette Company (The Procter & Gamble Company)
• Original Assignee: AER Energy Resources, Inc.
• Inventors: Golovin, Milton Neal, Kuznetsov, Irena
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/098,399
• Time in Patent Office: 713 Days
• Field of Search: 502/527.15, 502/101, 502/177, 502/185, 502/219, 502/221, 502/305, 502/313, 502/315, 502/316, 502/325, 29/623.5, 429/40, 429/44, 429/42, 429/101, 429/115, 429/249, 429/255, 204/290 R, 204/294
• US Class Current: 502/101
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 12/08 composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
• CPC Class Codes: H01M 2004/8689 Positive electrodes
• CPC Class Codes: H01M 4/8615 Bifunctional electrodes for rechargeable cells
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A catalyst composition for use in a rechargeable metal-air electrochemical cell comprises an oxygen evolution catalyst coated with a thin film deposition of carbon. This catalyst is useful to make an air electrode which produces more power in a metal-air cell then a metal-air cell having oxygen evolution catalyst without the thin carbon film.

Claims

1. Catalyst composition for use in a rechargeable metal-air electrochemical cell comprising an oxygen evolution catalyst coated with a thin film deposition coating of carbon, wherein the thin film of carbon has a thickness less than about 10 microns.

2. Catalyst composition as in claim 1 wherein the thin film of carbon has a thickness from about 10 to about 100 nm.

3. Catalyst composition as in claim 1 wherein the oxygen evolution catalyst comprises a tungsten compound.

4. Catalyst composition as in claim 1 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.

5. Catalyst composition as in claim 1 wherein the oxygen evolution catalyst comprises FeWO₄, WC with 1 to 20 percent fused Co, and NiS.

6. Method for making a catalyst composition for use in a rechargeable metal-air electrochemical cell comprising depositing a thin film coating of carbon on an oxygen evolution catalyst, wherein the thin film of carbon has a thickness less than about 10 microns.

7. Method as in claim 6 wherein the thin film carbon coating has a thickness from about 10 to about 100 nm.

8. Method as in claim 6 wherein the oxygen evolution catalyst comprises a tungsten compound.

9. Method as in claim 6 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.

10. Method as in claim 6 wherein the oxygen evolution catalyst comprises FeWO₄, WC with 1 to 20 percent fused Co, and NiS.

11. A bifunctional air electrode for use in a rechargeable metal-air electrochemical cell comprising:

an active layer comprising an oxygen reduction catalyst and an oxygen evolution catalyst, the oxygen evolution catalyst being coated with a thin film deposition coating of carbon, wherein the thin film of carbon has a thickness less than about 10 microns;

a wet-proofing layer laminated to the active layer to form a laminate; and

a current collector in electrical contact with the laminate.

12. A bifunctional air electrode as in claim 11 wherein the thin film coating of carbon has a thickness from about 10 to about 100 nm.

13. A bifunctional air electrode as in claim 11 wherein the oxygen evolution catalyst comprises a tungsten compound.

14. A bifunctional air electrode as in claim 11 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.

15. A bifunctional air electrode as in claim 11 wherein the oxygen evolution catalyst comprises FeWO₄, WC with 1 to 20 percent fused Co, and NiS.

16. A bifunctional air electrode as in claim 11 wherein the active layer further comprises carbon black and a non-wetting agent/binder.

17. A bifunctional air electrode as in claim 16 wherein the oxygen evolution catalyst is present in an amount from about 2 to about 20% by weight of the active layer, the thin film carbon coating has a thickness from about 10 to about 100 nm, the oxygen reduction catalyst is present in an amount from about 2 to about 20% by weight of the active layer, the carbon black is present in an amount from about 60 to about 90% by weight of the active layer, and the non-wetting agent/binder is present in an amount from about 16 to about 40% by weight of the active layer.

18. A bifunctional air electrode as in claim 16 wherein the non-wetting agent/binder is polytetrafluoroethylene.

19. Method for making a bifunctional air electrode for use in a rechargeable metal-air electrochemical cell comprising the steps of:

coating an oxygen evolution catalyst with a thin film deposition coating of carbon, wherein the thin film of carbon has a thickness less than about 10 microns;

admixing an oxygen reduction catalyst and the coated oxygen evolution catalyst to form an active layer mixture;

forming a laminate comprising a wet-proofing layer and an active layer, the active layer formed with the active layer mixture; and

positioning a current collector in electrical contact with the laminate.

20. Method as in claim 19 wherein the thin film coating of carbon has a thickness from about 10 to about 100 nm.

21. Method as in claim 19 wherein the oxygen evolution catalyst comprises a tungsten compound.

22. Method as in claim 19 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.

23. Method as in claim 19 wherein the oxygen evolution catalyst comprises FeWO₄, WC with 1 to 20 percent fused Co, and NiS.

24. Method as in claim 19 wherein the admixing step further comprises admixing carbon black and a non-wetting agent/binder with the oxygen evolution catalyst and the oxygen reduction catalyst.

25. Method as in claim 24 wherein the oxygen evolution catalyst is present in an amount from about 2 to about 20% by weight of the active layer, the thin film carbon coating has a thickness from about 10 to about 100 nm, the oxygen reduction catalyst is present in an amount from about 2 to about 20% by weight of the active layer, the carbon black is present in an amount from about 60 to about 90% by weight of the active layer, and the non-wetting agent/binder is present in an amount from about 16 to about 40% by weight of the active layer.

26. Method as in claim 24 wherein the non-wetting agent/binder is polytetrafluoroethylene.

27. Catalyst composition for use in a rechargeable metal-air electrochemical cell comprising an oxygen evolution catalyst coated with a thin film deposition coating consisting essentially of carbon.

28. Catalyst composition as in claim 27 wherein the oxygen evolution catalyst comprises a tungsten compound.

29. Catalyst composition as in claim 27 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.

30. Method for making a catalyst composition for use in a rechargeable metal-air electrochemical cell comprising depositing a thin film coating consisting essentially of carbon on an oxygen evolution catalyst.

31. Method as in claim 30 wherein the oxygen evolution catalyst comprises a tungsten compound.

32. Method as in claim 30 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.

33. A bifunctional air electrode for use in a rechargeable metal-air electrochemical cell comprising:

an active layer comprising an oxygen reduction catalyst and an oxygen evolution catalyst, the oxygen evolution catalyst being coated with a thin film deposition coating consisting essentially of carbon;

a wet-proofing layer laminated to the active layer to form a laminate; and

a current collector in electrical contact with the laminate.

34. A bifunctional air electrode as in claim 33 wherein the oxygen evolution catalyst comprises a tungsten compound.

35. A bifunctional air electrode as in claim 33 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.

36. Method for making a bifunctional air electrode for use in a rechargeable metal-air electrochemical cell comprising the steps of:

coating an oxygen evolution catalyst with a thin film deposition coating consisting essentially of carbon;

admixing an oxygen reduction catalyst and the coated oxygen evolution catalyst to form an active layer mixture;

forming a laminate comprising a wet-proofing layer and an active layer, the active layer formed with the active layer mixture; and

positioning a current collector in electrical contact with the laminate.

37. Method as in claim 36 wherein the oxygen evolution catalyst comprises a tungsten compound.

38. Method as in claim 36 wherein the oxygen evolution catalyst is selected from the group consisting of WC, FeWO₄, WS₂, WC with 1 to 20 percent fused Co, and NiS.