Fuel cell contact element including a TiO2 layer and a conductive layer

• US 20070003815A1
• Filed: 08/11/2005
• Published: 01/04/2007
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Vyas, Gayatri, Mikhail, Youssef, Abd Elhamid, Mahmoud, Trabold, Thomas
• Granted Patent: US 8,377,607 B2
• Time in Patent Office: Days
• US Class Current: 429/450
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/0202 Collectors; Separators, e.g. bipolar separators; Interconnectors
• CPC Class Codes: H01M 8/0204 Non-porous and characterised by the material
• CPC Class Codes: H01M 8/0206 Metals or alloys
• CPC Class Codes: H01M 8/021 Alloys based on iron
• CPC Class Codes: H01M 8/0221 Organic resins; Organic polymers
• 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 8/04291 Arrangements for managing water in solid electrolyte fuel cell systems H01M8/04119 takes precedence
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A flow field plate or bipolar plate for a fuel cell that includes a combination of TiO₂ and a conductive material that makes the bipolar plate conductive, hydrophilic and stable in the fuel cell environment. The TiO₂ and the conductive material can be deposited on the plate as separate layers or can be combined as a single layer. Either the TiO₂ layer or the conductive layer can be deposited first. In one embodiment, the conductive material is gold.

Claims

1. A fuel cell comprising a flow field plate being made of a plate material, said flow field plate including a plurality of flow channels responsive to a reactant gas, said flow field plate further including a TiO₂ layer and a conductive layer that combine to make the plate conductive, hydrophilic and stable in a fuel cell environment.

2. The fuel cell according to claim 1 wherein the plate material is selected from the group consisting of stainless steel, titanium, aluminum and a polymer-carbon composite based material.

3. The fuel cell according to claim 1 wherein the conductive layer is a gold layer.

4. The fuel cell according to claim 1 wherein the TiO₂ layer is deposited on the flow field plate before the conductive layer.

5. The fuel cell according to claim 1 wherein the conductive layer is deposited on the flow field plate before the TiO₂ layer.

6. The fuel cell according to claim 1 wherein the TiO₂ layer provides a contact angle for water accumulating in the flow channels to be below 20°

.

7. The fuel cell according to claim 1 wherein the TiO₂ layer is resistant to surface contamination.

8. The fuel cell according to claim 1 wherein the TiO₂ layer has a thickness in the range of 5-1000 nm.

9. The fuel cell according to claim 1 wherein the conductive layer has a thickness in the 2-10 nm range.

10. The fuel cell according to claim 1 wherein the TiO₂ layer and the conductive layer are deposited on the flow field plate by a process selected from the group consisting of an electron beam evaporation process, magnetron sputtering, a pulse plasma process, plasma enhanced chemical vapor deposition, an atomic layer deposition process, thermal spraying, spin coating, dip coating and a sol-gel process.

11. The fuel cell according to claim 1 wherein the flow field plate is selected from the group consisting of anode side flow field plates and cathode side flow field plates.

12. The fuel cell according to claim 1 wherein the fuel cell is part of a fuel cell stack on a vehicle.

13. A fuel cell comprising a flow field plate being made of a plate material, said flow field plate including a plurality of flow channels responsive to a reactant gas, said flow field plate including an outer layer being a mixture of TiO₂ and a conductive material that makes the plate conductive, hydrophilic and stable in a fuel cell environment.

14. The fuel cell according to claim 13 wherein the plate material is selected from the group consisting of stainless steel, titanium, aluminum and a polymer-carbon composite based material.

15. The fuel cell according to claim 13 wherein the conductive material is gold.

16. The fuel cell according to claim 13 wherein the outer layer provides a contact angle for water accumulating in the flow channels to be below 20°

.

17. The fuel cell according to claim 13 wherein the outer layer is resistant to surface contamination.

18. The fuel cell according to claim 13 wherein the outer layer has a thickness in the range of 5-1000 nm.

19. The fuel cell according to claim 13 wherein the outer layer is deposited on the flow field plate by a process selected from the group consisting of an electron beam evaporation process, magnetron sputtering, a pulse plasma process, plasma enhanced chemical vapor deposition, an atomic layer deposition process, thermal spraying, spin coating, dip coating and a sol-gel process.

20. The fuel cell according to claim 13 wherein the flow field plate is selected from the group consisting of anode side flow field plates and cathode side flow field plates.

21. The fuel cell according to claim 13 wherein the fuel cell is part of a fuel cell stack on a vehicle.

22. A fuel cell comprising a flow field plate being made of a plate material, said flow field plate including a plurality of flow channels responsive to a reactant gas, said flow field plate further including a TiO_x layer that makes the plate conductive, hydrophilic and stable in a fuel cell environment.

23. The fuel cell according to claim 22 wherein the plate material is selected from the group consisting of stainless steel, titanium, aluminum and a polymer-carbon composite based material.

24. The fuel cell according to claim 22 wherein the x in the TiO_x is in the range of 0.1-6.

25. The fuel cell according to claim 22 wherein the TiO_x layer provides a contact angle for water accumulating in the flow channels to be below 20°

.

26. The fuel cell according to claim 22 wherein the TiO_x layer is resistant to surface contamination.

27. The fuel cell according to claim 22 wherein the TiO_x layer has a thickness in the range of 5-1000 nm.

28. The fuel cell according to claim 22 wherein the TiO_x layer is deposited on the flow field plate by a process selected from the group consisting of an electron beam evaporation process, magnetron sputtering, a pulse plasma process, plasma enhanced chemical vapor deposition, an atomic layer deposition process, thermal spraying, spin coating, dip coating and a sol-gel process.

29. The fuel cell according to claim 22 wherein the flow field plate is selected from the group consisting of anode side flow field plates and cathode side flow field plates.

30. The fuel cell according to claim 22 wherein the fuel cell is part of a fuel cell stack on a vehicle.

31. A method for making a flow field plate for a fuel cell, said method comprising:

providing a flow field plate being made of a plate material; and

depositing a non-stoichiometric metal oxide layer on the flow field plate that makes the plate conductive, hydrophilic and stable in a fuel cell environment.

32. The method according to claim 31 further comprising depositing a conductive layer on the flow field plate.

33. The method according to claim 32 further wherein depositing a non-stoichiometric metal oxide layer and a conductive layer includes depositing the conductive layer on the flow field plate and depositing the non-stoichiometric metal oxide layer on the conductive layer.

34. The method according to claim 32 further wherein depositing a non-stoichiometric metal oxide layer and a conductive layer includes depositing the non-stoichiometric metal oxide layer on the flow field plate and depositing the conductive layer on the non-stoichiometric metal oxide layer.

35. The method according to claim 32 wherein the conductive layer is a gold layer.

36. The method according to claim 31 wherein the non-stoichiometric metal oxide layer is TiO_x where x is in the range of 0.1-6.