Electrode layer arrangements in an electrochemical device

• US 20040202924A1
• Filed: 12/23/2003
• Published: 10/14/2004
• Est. Priority Date: 06/25/2001
• Status: Abandoned Application

• Current Assignee: Sofc Holdings LLC
• Original Assignee: Celltech Power, Inc.
• Inventors: Wang, Gonghou, Bai, Wei, Tao, Tao T., Rackey, Scott
• Application Number:
  US10/744,602
• Publication Number:
  US 20040202924A1
• Time in Patent Office: Days
• US Class Current: 429/102
• 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 16/003 of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2004/8684 Negative electrodes
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2300/0077 based on zirconium oxide
• CPC Class Codes: H01M 4/0407 by coating on an electrolyte layer
• CPC Class Codes: H01M 4/0438 by electrochemical processing electroless electrochemical plating C23C18/54
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8647 consisting of more than one material, e.g. consisting of composites
• CPC Class Codes: H01M 4/9025 Oxides specially used in fuel cell operating at high temperature, e.g. SOFC
• CPC Class Codes: H01M 4/9033 Complex oxides, optionally doped, of the type M1MeO3, M1 being an alkaline earth metal or a rare earth, Me being a metal, e.g. perovskites
• CPC Class Codes: H01M 4/9041 Metals or alloys H01M4/92 takes precedence
• CPC Class Codes: H01M 4/9066 of metal-ceramic composites or mixtures, e.g. cermets
• CPC Class Codes: H01M 8/00 Fuel cells; Manufacture thereof
• CPC Class Codes: H01M 8/0206 Metals or alloys
• CPC Class Codes: H01M 8/0213 Gas-impermeable carbon-containing materials
• CPC Class Codes: H01M 8/1233 with one of the reactants being liquid, solid or liquid-charged
• CPC Class Codes: H01M 8/1253 the electrolyte containing zirconium oxide
• CPC Class Codes: H01M 8/18 Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention relates to an electrochemical device that can operate either as a fuel cell or a battery, and particularly to a device including an electrode arrangement involving a liquid metal positioned against a layer comprising anodic material. When a fuel is positioned adjacent the layer comprising anodic material, a tri-junction area results in which electrochemical or anode regeneration processes can occur. The layer comprising anodic material can also function as a catalyst, for catalyzing electrochemical reactions, or as a protective layer for the electrode against various degradative processes.

Claims

1. An electrochemical device, comprising:

an anodic material positioned between an electrolyte and a liquid metal, wherein the liquid metal functions as an anode.

2. The electrochemical device of claim 1, comprising an anodic layer positioned between the electrolyte layer and the liquid metal, wherein the anodic layer comprises the anodic material.

3. The electrochemical device of claim 1, wherein the anodic material has an ionic conductivity of at least about 0.01 S/cm, at a temperature at which the device is operable.

4. The electrochemical device of claim 2, wherein the anodic layer has an electronic conductance greater than or equal to that of the electrolyte layer.

5. The electrochemical device of claim 4, wherein the electronic conductance of the anodic layer is at least about 0.001 S/cm, at a temperature at which the device is operable.

6. The electrochemical device of claim 2, wherein the anodic material is capable of transporting oxygen through an anodic layer/electrolyte interface.

7. The electrochemical device of claim 6, wherein a total oxygen flux through the anodic layer/electrolyte interface is at least about 1015 oxygens/s·

cm2.

8. The electrochemical device of claim 2, wherein the anodic layer further comprises material not able to function as the anode.

9. The electrochemical device of claim 8, wherein the anodic layer comprises pores and the pores comprise anodic material.

10. The electrochemical device of claim 2, wherein the anodic layer comprises an oxide of the liquid metal.

11. The electrochemical device of claim 10, wherein the liquid metal comprises an alloy comprising a first metal and a second metal.

12. The electrochemical device of claim 11, wherein the anodic layer comprises an oxide of the first metal and an oxide of the second metal.

13. The electrochemical device of claim 12, wherein, in the liquid metal, the mass fraction of the first metal is greater than the mass fraction of the second metal and wherein, in the anodic layer, the mass fraction of the oxide of the second metal is greater than the mass fraction of the oxide of the first metal.

14. The electrochemical device of claim 13, wherein the second metal comprises about 0.1 to about 5% of the mass of the liquid metal.

15. The electrochemical device of claim 14, wherein the second metal comprises about 0.5 to about 2% of the mass of the liquid metal.

16. The electrochemical device of claim 13, wherein the first metal is selected from a group consisting of bismuth, lead, antimony and tin and the second metal is selected from the group consisting of indium, iron, cobalt, gallium, aluminum, calcium, magnesium, beryllium, scandium, barium, yttrium, zirconium, strontium, titanium, manganese, lanthanides and mixtures thereof.

17. An electrochemical device, comprising a catalyst positioned adjacent to an electrolyte layer, the catalyst further contacting a liquid metal.

18. The electrochemical device of claim 17, wherein the catalyst comprises a layer comprising catalytic material.

19. The electrochemical device of claim 17, wherein the catalyst comprises localized sites of catalytic material distributed on the electrolyte layer.

20. An anode, comprising a liquid metal positioned adjacent a ceramic having an ionic conductivity of at least about 0.01 S/cm and an electrical conductance of at least about 0.001 S/cm.

21. A method of forming a layer in an electrochemical device, comprising:

providing an anode comprising a liquid first metal such that it is in contact with an electrolyte; and

depositing a portion of the first metal on the electrolyte as a first metal oxide.

22. The method of claim 21, wherein depositing a portion of the first metal further comprises maintaining a first voltage in the electrochemical device.

23. The method of claim 21, wherein the first metal is selected from a group consisting of tin, antimony, lead, bismuth and mixtures thereof.

24. The method of claim 21, further comprising

providing a liquid second metal to the anode;

and

depositing a portion of the second metal on the electrolyte as a second metal oxide.

25. The method of claim 24, wherein the second metal is selected from a group consisting of indium, iron, cobalt, chromium, gallium, aluminum, calcium, magnesium, beryllium, scandium, barium, yttrium, zirconium, strontium, titanium, manganese, lanthanides, and mixtures thereof.

26. The method of claim 24, wherein depositing the portion of the first metal comprises maintaining a first voltage in the electrochemical device and depositing the portion of the second metal comprises maintaining a second voltage in the electrochemical device.

27. The method of claim 26, wherein the portion of the second metal is deposited before the portion of the first metal is deposited.

28. The method of claim 21, wherein the electrochemical device is a solid oxide fuel cell.

30. The electrochemical device of claim 24, wherein the anode comprises the liquid metal.

29. An electrochemical device, comprising:

an anode; and

a current collector comprising a liquid metal in electronic communication with the anode.

31. An electrochemical device, comprising:

an anodic layer positioned between an electrolyte and a liquid metal, wherein the anodic layer comprises a material capable of transporting oxygen through an anodic layer/electrolyte interface.

32. An electrochemical device, comprising:

an electric circuit comprising a liquid metal; and

an anodic material positioned between an electrolyte and the liquid metal.