Planar fuel cell assembly

• US 6,492,053 B1
• Filed: 04/10/2000
• Issued: 12/10/2002
• Est. Priority Date: 06/10/1997
• Status: Expired due to Term

• Current Assignee: Chaozhou Three-Circle Company Limited
• Original Assignee: Ceramic Fuel Cells Limited
• Inventors: Hickey, Darren Bawden, Donelson, Richard
• Primary Examiner(s): Chaney, Carol
• Assistant Examiner(s): YUAN, DAH WEI D
• Application Number:
  US09/445,735
• Time in Patent Office: 974 Days
• Field of Search: 429/12, 429/13, 429/34, 429/35, 429/38
• US Class Current: 429/458
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2300/0074 Ion conductive at high temperature
• CPC Class Codes: H01M 8/0206 Metals or alloys
• CPC Class Codes: H01M 8/0226 in the form of mixtures
• CPC Class Codes: H01M 8/0228 in the form of layered or coated products
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/0254 corrugated or undulated
• CPC Class Codes: H01M 8/0271 Sealing or supporting means around electrodes, matrices or membranes
• CPC Class Codes: H01M 8/242 comprising framed electrodes or intermediary frame-like gaskets H01M8/2425, H01M8/244 take precedence
• CPC Class Codes: H01M 8/2428 Grouping by arranging unit cells on a surface of any form, e.g. planar or tubular
• CPC Class Codes: H01M 8/2432 Grouping of unit cells of planar configuration
• CPC Class Codes: H01M 8/2465 Details of groupings of fuel cells
• CPC Class Codes: H01M 8/247 Arrangements for tightening a stack, for accommodation of a stack in a tank or for assembling different tanks
• CPC Class Codes: H01M 8/2483 characterised by internal manifolds
• CPC Class Codes: H01M 8/249 comprising two or more groupings of fuel cells, e.g. modular assemblies
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell assembly (10) comprising a stack of a plurality of planar fuel cells (16) each comprising an electrolyte layer (20) having an anode layer (18) on one side and a cathode layer (22) on the other side and a plurality of interconnect members (12, 14), each fuel cell (16) being disposed between and in electrical contact with an adjacent pair of interconnect members (12, 14) with oxygen-containing gas passage means (28) being formed between the cathode layer (22) of each fuel cell (16) and the adjacent interconnect member (14) and fuel gas passage means (38, 42) being formed between the anode layer (18) of each fuel cell (16) and the adjacent interconnect member (12), and wherein a chamber (36) of greater height than the thickness of the respective fuel cell (16) is defined between the adjacent interconnect members (12, 14) in each pair within which the fuel cell (16) is received, and electrically conductive compressible means (32, 38, 40, 42) also disposed within the chamber (36) in electrical contact with a first side (18) of the fuel cell (16) and the adjacent interconnect member (12) urges the fuel cell (16) towards the adjacent interconnect member (14) on the second side (22) thereof to maintain the fuel cell (16) in electrical contact with both adjacent interconnect members (12, 14). The fuel cell assembly (10) may comprise a single fuel cell (16) between two interconnect members (12, 14). The compressible means (32) may comprise a corrugated sheet (42) of Ni or Ni alloy.

Claims

1. A fuel cell assembly comprising a planar fuel cell having an electrolyte layer with an anode layer on one side and a cathode layer on the other side, the fuel cell being disposed between and in electrical contact with respective interconnect members, oxygen-containing gas passage means being formed between the cathode layer and the adjacent interconnect member and fuel gas passage means being formed between the anode layer and the adjacent interconnect member, and wherein a chamber of greater height than the thickness of the fuel cell is defined between the interconnect members within which the fuel cell is received and metallic electrically conductive compressible means also disposed within the chamber in electrical contact with a first side of the fuel cell and the adjacent interconnect member provides compressive force against the fuel cell towards the adjacent interconnect member on a second side thereof to maintain the fuel cell in electrical contact with both interconnect members.

2. A fuel cell assembly according to claim 1 wherein the electrically conductive compressible means is disposed on the anode side of the fuel cell.

3. A fuel cell assembly according to claim 2 wherein the electrically conductive compressible means is formed of a material selected from the group consisting of a metal from Groups 8-11 of the Periodic Table, an alloy of one or more of such metals, and such a metal which has been oxide dispersion strengthened.

4. A fuel cell assembly according to claim 2 wherein the electrically conductive compressible means is selected from a structure which retains some resilience at the operating temperature and a composite of a porous brittle material and a metal.

5. A fuel cell assembly according to claim 4 wherein the electrically conductive compressible means comprises a corrugated sheet selected from the group consisting of metal and metallic material.

6. A fuel cell assembly according to claim 5 wherein a flat sheet selected from the group consisting of metal and metallic material is disposed between the corrugated sheet and the adjacent interconnect member.

7. A fuel cell assembly according to claim 5 wherein the electrically conductive compressible means is joined to the adjacent interconnect member.

8. A fuel cell assembly according to claim 5 wherein the electrically conductive compressible means forms the gas passage means between the first side of the fuel cell and the adjacent interconnect member and contacts a flat side of said adjacent interconnect member.

9. A fuel cell assembly according to claim 1 wherein the electrically conductive compressible means is disposed on the upper side of the fuel cell.

10. A fuel cell assembly according to claim 1 wherein for each fuel cell a seal is provided around a peripheral portion of the fuel cell between the second side thereof and the adjacent interconnect member to seal the oxygen-containing gas and fuel gas in the chamber from each other.

11. A fuel cell assembly according to claim 10 wherein the seal is compressible in use.

12. A fuel cell assembly according to claim 10 wherein sealing means selected from the group consisting of the seal and a separate seal member extends around the chamber to at least partially seal the chamber from the exterior.

13. A fuel cell assembly according to claim 11 wherein the seal is rigid at room temperature and viscous at the cell operating temperature.

14. A fuel cell assembly according to claim 13 wherein the electrode layer on the second side of the fuel cell is initially spaced from the adjacent interconnect member by the rigid seal at room temperature and abuts and makes electrical contact with said adjacent interconnect member at the fuel cell operating temperature as the viscous seal material compresses under load.

15. A fuel cell assembly according to claim 13 wherein the seal is in the form of a glass-containing gasket.

16. A fuel cell assembly according to claim 15 wherein the gasket has plural layers of glass-containing material.

17. A fuel cell assembly according to claim 12 wherein the sealing means is a separate seal member and the separate seal member has the same properties as the seal.

18. A fuel cell assembly according to claim 1 wherein an insulating spacer extends around the fuel cell and the electrically conductive compressible means to at least partly define the chamber.

19. A fuel cell assembly according to claim 1 which is internally manifolded.

20. A fuel cell assembly according to claim 1 wherein the fuel cell is one of an array in a layer of plural planar fuel cells in the assembly, each disposed in a respective said chamber of greater height than the thickness of the fuel cell defined between the interconnect members, a respective said electrically conductive compressible means also being disposed within each said chamber in electrical contact with the first side of the respective fuel cell and the adjacent interconnect member to bias the fuel cell towards the adjacent interconnect member on the second side thereof to maintain the fuel cell in electrical contact with both interconnect members.

21. A fuel cell assembly comprising a stack of a plurality of planar fuel cells each comprising an electrolyte layer having an anode layer on one side and a cathode layer on the other side and a plurality of interconnect members, each fuel cell being disposed between and in electrical contact with an adjacent pair of interconnect members with oxygen-containing gas passage means being formed between the cathode layer of each fuel cell and the adjacent interconnect member and fuel gas passage means being formed between the anode layer of each fuel cell and the adjacent interconnect member, and wherein a chamber of greater height than the thickness of the respective fuel cell is defined between the adjacent interconnect members in each pair within which the fuel cell is received, and metallic electrically conductive compressible means also disposed within the chamber in electrical contact with a first side of the fuel cell and the adjacent interconnect member provides compressive force against the fuel cell towards the adjacent interconnect member on the second side thereof to maintain the fuel cell in electrical contact with both adjacent interconnect members.

22. A fuel cell assembly according to claim 21 wherein for each fuel cell the electrically conductive compressible means is disposed on the anode side of the fuel cell.

23. A fuel cell assembly according to claim 22 wherein the electrically conductive compressible means is formed of a material selected from the group consisting of a metal from Groups 8-11 of the Periodic Table, an alloy of one or more of such metals, and such a metal which has been oxide dispersion strengthened.

24. A fuel cell assembly according to claim 22 wherein the electrically conductive compressible means is selected from a structure which retains some resilience at the operating temperature and a composite of a porous brittle material and a metal.

25. A fuel cell assembly according to claim 24 wherein the electrically conductive compressible means comprises a corrugated sheet selected from the group consisting of metal and metallic material.

26. A fuel cell assembly according to claim 25 wherein a flat sheet selected from the group consisting of metal and metallic material is disposed between the corrugated sheet and the adjacent interconnect member.

27. A fuel cell assembly according to claim 25 wherein the electrically conductive compressible means is joined to the adjacent interconnect member.

28. A fuel cell assembly according to claim 25 wherein the electrically conductive compressible means forms the gas passage means between the first side of the fuel cell and the adjacent interconnect member and contacts a flat side of said adjacent interconnect member.

29. A fuel cell assembly according to claim 21 wherein for each fuel cell the electrically conductive compressible means is disposed on the upper side of the fuel cell.

30. A fuel cell assembly according to claim 21 wherein for each fuel cell a seal is provided around a peripheral portion of the fuel cell between the second side thereof and the adjacent interconnect member to seal the oxygen-containing gas and fuel gas in the chamber from each other.

31. A fuel cell assembly according to claim 30 wherein the seal is compressible in use.

32. A fuel cell assembly according to claim 30 wherein sealing means selected from the group consisting of the seal and a separate seal member extending around the chamber to at least partially seal the chamber from the exterior.

33. A fuel cell assembly according to claim 21 wherein for each fuel cell an insulating spacer extends around the fuel cell and the electrically conductive compressible means to at least partly define the chamber.

34. A fuel cell assembly according to claim 21 which is internally manifolded.

35. A fuel cell assembly according to claim 21 wherein each of said fuel cells is one of an array in a respective layer of plural planar fuel cells in the assembly, each disposed in a respective said chamber of greater height than the thickness of the fuel cell defined between the interconnect members, a respective said electrically conductive compressible means also being disposed within each said chamber in electrical contact with the first side of the respective fuel cell and the adjacent interconnect member to bias the fuel cell towards the adjacent interconnect member on the second side thereof to maintain the fuel cell in electrical contact with both interconnect members.

36. A fuel cell assembly according to claim 23 wherein the metal is nickel.

37. A fuel cell assembly according to claim 25 wherein the corrugated sheet is of expanded material.

38. A fuel cell assembly according to claim 25 wherein a flat sheet selected from the group consisting of metal and metallic material is disposed between the corrugated sheet and the adjacent interconnect member.

39. A fuel cell assembly according to claim 38 wherein the flat sheet is of expanded material.

40. A fuel cell assembly according to claim 30 wherein the seal is in contact with the electrolyte layer of the fuel cell.

41. A fuel cell assembly according to claim 31 wherein the seal is rigid at room temperature and viscous at the cell operating temperature.

42. A fuel cell assembly according to claim 41 wherein the electrode layer on the second side of the fuel cell is initially spaced from the adjacent interconnect member by the rigid seal at room temperature and abuts and makes electrical contact with said adjacent interconnect member at the fuel cell operating temperature as the viscous seal material compresses under load.

43. A fuel cell assembly according to claim 41 wherein the seal is in the form of a glass-containing gasket.

44. A fuel cell assembly according to claim 43 wherein the gasket has plural layers of glass-containing material.

45. A fuel cell assembly according to claim 32 wherein the sealing means is a separate seal member and the separate seal member has the same properties as the seal.

46. A fuel cell assembly according to claim 33 wherein a seal member is disposed between the insulating spacer and the interconnect member adjacent to the first side of the fuel cell.

47. A fuel cell assembly according to claim 35 wherein the interconnect members adjacent a common side of more than one of the fuel cells in each array are formed in a single plate.