Oxidation facilitator

• US 20070048555A1
• Filed: 12/05/2005
• Published: 03/01/2007
• Est. Priority Date: 06/10/2003
• Status: Active Grant

• Current Assignee: Sofc Holdings LLC
• Original Assignee: Celltech Power, Inc.
• Inventors: Bai, Wei, Rackey, Scott, Blake, Adam
• Granted Patent: US 7,745,064 B2
• Time in Patent Office: Days
• US Class Current: 429/408
• CPC Class Codes: H01M 2004/8684 Negative electrodes
• CPC Class Codes: H01M 4/86 Inert electrodes with catalytic activity, e.g. for fuel cells
• CPC Class Codes: H01M 4/8626 characterised by the form
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• 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 4/905 specially used in fuel cell operating at high temperature, e.g. SOFC
• CPC Class Codes: H01M 8/0217 Complex oxides, optionally doped, of the type AMO3, A being an alkaline earth metal or rare earth metal and M being a metal, e.g. perovskites
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/1213 characterised by the electrode/electrolyte combination or the supporting material
• CPC Class Codes: H01M 8/124 characterised by the process of manufacturing or by the material of the electrolyte
• CPC Class Codes: H01M 8/1253 the electrolyte containing zirconium oxide
• CPC Class Codes: H01M 8/20 Indirect fuel cells, e.g. fuel cells with redox couple being irreversible H01M8/18 takes precedence
• 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

Fuel oxidation facilitators for use in electrochemical devices are described, as well as devices incorporating facilitators and methods of their use. Exemplary facilitators separate a liquid anode of a fuel cell from fuel supplied to the fuel cell, and facilitate oxidation of the fuel.

Claims

1. A fuel cell, comprising:

a compartment constructed and arranged to contain an anode that is a fluid during operation of the fuel cell;

a fuel manifold attachable to a source of fuel for the fuel cell; and

a fuel oxidation facilitator across which oxidation of a fuel provided by the manifold via an anode in the anode compartment can occur during fuel cell operation.

2. A fuel cell as in claim 1, wherein the fuel oxidation facilitator is constructed and arranged to prevent flow between a fuel and a fluid anode during fuel cell operation.

3. A fuel cell as in claim 2, wherein the fuel oxidation facilitator includes at least a portion physically separating a fuel from a fluid anode during fuel cell operation, across which portion fuel oxidation can occur.

4. A fuel cell as in claim 3, wherein the fuel oxidation facilitator physically completely separates a fuel from a fluid anode during fuel cell operation.

5. A fuel cell as in claim 2, wherein the fuel oxidation facilitator includes at least one pore of dimension allowing physical contact between a fuel and an anode under operating conditions of the fuel cell.

6. A fuel cell as in claim 5, wherein the fuel oxidation facilitator includes a section separating a fuel and a liquid anode, essentially the entire section comprising a porous article including pores of dimension allowing physical contact between the fuel and the anode under operating conditions of the fuel cell.

7. A fuel cell as in claim 5, wherein the fuel oxidation facilitator includes at least a portion physically separating a fuel from a fluid anode during fuel cell operation, across which portion fuel oxidation can occur.

8. A fuel cell as in claim 1, wherein the fuel oxidation facilitator defines a portion of the anode compartment.

9. A fuel cell as in claim 8, constructed and arranged such that the fuel cell oxidation facilitator, at least one portion thereof, is the sole fuel cell component separating an anode in the anode compartment from a fuel provided in the fuel manifold.

10. A fuel cell as in claim 1, wherein the fuel oxidation facilitator defines a portion of the fuel manifold.

11. A fuel cell as in claim 10, constructed and arranged such that the fuel cell oxidation facilitator, at least one portion thereof, is the sole fuel cell component separating an anode in the anode compartment from a fuel provided in the fuel manifold.

12. A fuel cell as in claim 1, further comprising an anode that is a fluid during operation of the fuel cell.

13. A fuel cell as in claim 12, wherein a substantial portion of the anode is a liquid during operation of the fuel cell.

14. A fuel cell as in claim 1, wherein the oxidation facilitator comprises a mixed ion/electron conductor.

15. A fuel cell as in claim 1, wherein the fuel oxidation facilitator includes at least one ionically-conductive portion.

16. A fuel cell as in claim 1, further comprising a fuel, a substantial portion of which is a gas under operating conditions of the fuel cell.

17. A fuel cell as in claim 1, wherein the fuel oxidation facilitator is substantially cylindrical.

18. A fuel cell as in claim 1, wherein the fuel manifold includes or is connected to an exhaust conduit and the cell further comprises a fuel delivery conduit having an exit for delivery of fuel at an end of the fuel manifold substantially opposite the exhaust end.

19. A fuel cell as in claim 1, further comprising an auxiliary electrical circuit constructed and arranged to drive oxidant toward fuel across the oxidation facilitator.

20. A fuel cell, comprising:

an anode;

a fuel manifold attachable to a source of fuel for the cell; and

a fuel oxidation facilitator across which, at a location where the anode is physically separated from a fuel provided by the manifold, oxidation of the fuel via the anode can occur during fuel cell operation.

21. A fuel cell as in claim 20, wherein a substantial portion of the fuel is a gas and a substantial portion of the anode is a fluid under operating conditions of the fuel cell.

22. A fuel cell as in claim 21, wherein a substantial portion of the anode is a liquid under operating conditions of the fuel cell.

23. A fuel cell as in claim 20, wherein a substantial portion of the fuel is a gas under operating conditions of the fuel cell.

24. A fuel cell as in claim 20, wherein a substantial portion of the anode is a solid under operating conditions of the fuel cell.

25. A fuel cell as in claim 24, wherein a substantial portion of the fuel is a gas under operating conditions of the fuel cell.

26. A fuel cell as in claim 20, wherein the oxidation facilitator comprises a mixed ion/electron conductor.

27. An article, comprising:

a fuel oxidation facilitator, for use in a fuel cell comprising a fluid anode that oxidizes a fuel provided to the fuel cell during cell operation, the facilitator constructed and arranged to be integrated with other fuel cell components wherein oxidation of the fuel by the anode occurs across at least a portion of the facilitator.

28. An article as in claim 27, wherein the fuel oxidation facilitator is constructed and arranged to prevent flow between a fuel and a fluid anode during fuel cell operation.

29. An article as in claim 27, wherein the fuel oxidation facilitator includes at least a portion able to physically separate a fuel from a fluid anode during fuel cell operation, across which portion fuel oxidation can occur.

30. An article as in claim 27, comprising a mixed ion/electron conductor.

31. An article, comprising:

a fuel oxidation facilitator, for use in a fuel cell comprising an anode that oxidizes a fuel provided to the fuel cell during cell operation, the facilitator constructed and arranged to be integrated with other fuel cell components, and including one portion constructed and arranged to physically separate the fuel from the anode during fuel cell operation, across which portion fuel oxidation can occur.

32. An article as in claim 31, comprising a mixed ion/electron conductor.

33. A method, comprising an act of:

oxidizing a fuel with an oxidant at an anode of a fuel cell at a location where the anode and fuel are physically separated from each other.

34. A method as in claim 33, wherein the anode and fuel are completely physically separated from each other in the fuel cell.

35. A method as in claim 33 wherein, at least one location, the anode and fuel are allowed to physically contact each other.

36. A method, comprising an act of:

oxidizing a gaseous fuel with an oxidant at a liquid anode of a fuel cell while containing the liquid anode within a compartment separate from a compartment within which the gaseous fuel is provided, form which the liquid anode is not free to flow or migrate into the fuel compartment during operation.

37. A method as in claim 36, comprising allowing oxidation of the gaseous fuel to occur across an oxidation facilitator that prevents the liquid anode from flowing or migrating into the fuel compartment during operation.

38. A method as in claim 37, wherein the oxidation facilitator is a mixed ionic/electronic conductor.

39. A method as in claim 37, wherein the oxidation facilitator includes porous, open channels allowing physical contact between the fuel and the anode.

40. A method as in claim 37, wherein the oxidation facilitator prevents liquid anode physical flow into the fuel compartment.

41. A method as in claim 37, wherein the oxidation facilitator prevents accumulation of metal anode outside of the anode compartment.

42. A method as in claim 36, wherein the fuel is hydrogen.

43. A method as in claim 36, wherein the anode is a liquid metal.

44. A method as in claim 36, wherein oxidation of the gaseous fuel occurs at a location where the anode and fuel are physically separated from each other.

45. A fuel cell, comprising:

an anode;

a fuel manifold attachable to a source of fuel for the cell; and

a fuel oxidation facilitator across which, at a location where the anode is physically separated from a fuel provided by the manifold, oxidation of the fuel by the anode can occur during fuel cell operation.