Claims
- 1. A flow field for supplying a fluid reactant to a fluid diffusion electrode in a fuel cell, said flow field comprising one or more fluid distribution channels having an average channel width W and separated by landings, said fluid diffusion electrode comprising a fluid diffusion layer, and said landings in said flow field mechanically supporting said fluid diffusion layer, wherein said flow field is characterized in that said one or more channels are configured such that essentially any unsupported rectangular surface of length L and width W on said fluid diffusion layer has a ratio L/W less than about 3.
- 2. The flow field of claim 1 wherein said ratio L/W is less than about 2.
- 3. The flow field of claim 1 wherein W is less than about 1 mm.
- 4. The flow field of claim 3 wherein L is less than about 3 mm.
- 5. The flow field of claim 4 wherein L is less than about 2 mm.
- 6. The flow field of claim 1 wherein said one or more fluid distribution channels are shaped in a wave form.
- 7. The flow field of claim 6 wherein said one or more fluid distribution channels are sinusoidal shaped.
- 8. The flow field of claim 1 comprising a plurality of fluid distribution channels.
- 9. The flow field of claim 8 wherein said plurality of fluid distribution channels are cross connected.
- 10. A fuel cell comprising a fluid diffusion electrode comprising a fluid diffusion layer wherein said fluid diffusion layer is mechanically supported by the flow field of claim 1.
- 11. The fuel cell of claim 10 wherein said fuel cell is a solid polymer electrolyte fuel cell.
- 12. The fuel cell of claim 10 wherein said fluid diffusion layer has a Taber stiffness less than about 2.
- 13. The fuel cell of claim 10 wherein said fluid diffusion layer is mechanically anisotropic.
- 14. A method of mechanically supporting a fluid diffusion layer in a fuel cell with a flow field, said flow field comprising one or more fluid distribution channels having an average channel width W and separated by landings which mechanically support said fluid diffusion layer, said method comprising configuring said one or more fluid distribution channels such that essentially any unsupported rectangular surface of length L and width W on said fluid diffusion layer has a ratio L/W less than about 3.
- 15. The method of claim 14 wherein said one or more fluid distribution channels are sinusoidal shaped.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 09/567,500 filed May 9, 2000, entitled “Differential Pressure Fluid Flow Fields For Fuel Cells”. The '500 application is incorporated herein by reference in its entirety.
US Referenced Citations (2)
Number |
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Date |
Kind |
5863671 |
Spear et al. |
Jan 1999 |
A |
6007933 |
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Dec 1999 |
A |
Foreign Referenced Citations (1)
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
09/567500 |
May 2000 |
US |
Child |
09/752548 |
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US |