Electrochemical cell having a deposited gas electrode

• US 20080138696A1
• Filed: 12/08/2006
• Published: 06/12/2008
• Est. Priority Date: 12/08/2006
• Status: Active Grant

• Current Assignee: Energizer Brands, LLC (Energizer Holdings, Inc.)
• Original Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Inventors: Bartling, Brandon A.
• Granted Patent: US 7,695,840 B2
• Time in Patent Office: Days
• US Class Current: 429/42
• 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 4/621 Binders
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8657 layered
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

An electrochemical cell comprising a gas electrode, including a deposited layer, and a counter electrode. The gas electrode is an electrode that either utilizes a gas as the active material that is reduced by the gas electrode or produces a gas by oxidation at the gas electrode. In a preferred embodiment, the gas electrode is a thin film electrode including a deposited current collector and deposited active material oxidation or reduction layer. A control layer can be disposed between the gas electrode and the counter electrode to control the diffusion of electrolyte into the gas electrode. Methods for making electrochemical cells having gas electrodes are disclosed.

Claims

1. An electrochemical cell, comprising:

a gas electrode, wherein the gas electrode is a gas consuming or gas generating electrode; and

a counter electrode;

wherein the gas electrode comprises;

an air permeable electrode support;

a current collector coating deposited on a portion of the electrode support, said coating derived from a composition comprising a conductive material, a current collector binder, and a current collector carrier; and

a catalytically active material coating deposited on a portion of the electrode support, said active material coating derived from a composition comprising activated carbon, an active material binder, and an active material carrier, wherein at least a portion of said active material coating contacts the current collector coating.

2. The cell according to claim 1, wherein the gas electrode is the gas generating electrode, and wherein the gas generating electrode is an oxygen generating electrode or a hydrogen generating electrode.

3. The cell according to claim 1, wherein the gas electrode is the gas consuming electrode.

4. The cell according to claim 1, wherein the electrode support comprises polytetrafluoroethylene, polytetrafluoroethylene coated paper, polyester, or porous aluminum oxide.

5. The cell according to claim 4, wherein the electrode support comprises polytetrafluoroethylene coated paper.

6. The cell according to claim 1, wherein the current collector conductive material comprises an electrochemically stable metal or electrically conductive polymer, or a combination thereof.

7. The cell according to claim 6, wherein the current collector conductive material comprises silver, copper, or nickel metal or alloy, or a combination thereof.

8. The cell according to claim 6, wherein the current collector binder is conductive polyaniline.

9. The cell according to claim 6, wherein the current collector binder is non-conductive and comprises silicon, cyanoacrylate, epoxy, or a combination thereof.

10. The cell according to claim 6, wherein the binder comprises an epoxy.

11. The cell according to claim 1, wherein the current collector carrier comprises an alcohol or acetone.

12. The cell according to claim 1, wherein the current collector coating is a printed coating.

13. The cell according to claim 1, wherein the current collector coating comprises one or more void areas therein which have been filled with the catalytically active material coating, wherein the catalytically active material coating in the void area contacts the electrode support.

14. The cell according to claim 1, wherein the current collector coating includes one or more leads for electrical connection to a device.

15. The cell according to claim 1, wherein the catalytically active material binder comprises polyvinylpyrrolidone or polyvinylbutyral, or a combination thereof.

16. The cell according to claim 1, wherein the catalytically active material further includes a catalyst.

17. The cell according to claim 16, wherein the catalyst comprises manganese dioxide, or a nano metal.

18. The cell according to claim 17, wherein the nano metal catalyst is present and is nano-nickel, nano-manganese or nano-silver.

19. The cell according to claim 1, wherein the active material carrier comprises an alcohol.

20. The cell according to claim 1, wherein the catalytically active material coating has a dry thickness that ranges from 6.25 μ

m to 203.2 μ

m.

21. The cell according to claim 20, wherein the catalytically active material coating has a dry thickness that ranges from 25.4 μ

m to 76.2 μ

m.

22. The cell according to claim 1, wherein the catalytically active material coating is deposited on a portion of both of the electrode support and the current collector coating.

23. The cell according to claim 1, wherein a control layer comprising a fluoropolymer is present in the cell between the gas electrode and the counter electrode.

24. The cell according to claim 23, wherein a separator is present between the gas electrode and the counter electrode, and wherein the control layer is present between the gas electrode and the separator.

25. The cell according to claim 23, wherein the control layer functions as a separator and wherein the cell is free of any other separator between the gas electrode and the counter electrode.

26. The cell according to claim 23, wherein the control layer is deposited on a surface of the gas electrode facing the counter electrode.

27. The cell according to claim 26, wherein a thickness of the control layer is from 0.25 μ

m to 1.5 μ

m.

28. The cell according to claim 27, wherein the control layer has a thickness of 1 micron.

29. A method for forming an electrochemical cell, comprising the steps of:

providing an air permeable electrode support;

depositing a current collector coating on a portion of the electrode support from a current collector solution composition; and

depositing an active material coating on a portion of the electrode support from an active material mixture solution composition comprising activated carbon, an active material binder, and an active material carrier, wherein at least a portion of said active material coating contacts the current collector coating.

30. The method according to claim 29, wherein the active material coating further comprises a catalyst.

31. The method according to claim 29, further comprising the step of combining the gas electrode with a counter electrode and an aqueous electrolyte, with a control layer comprising a fluoropolymer disposed between the gas electrode and the counter electrode.

32. The method according to claim 31, wherein the control layer is deposited on a surface of the gas electrode facing the counter electrode, and a separator is disposed between the control layer and the counter electrode.