Fuel cell structure

• US 20040038117A1
• Filed: 09/05/2003
• Published: 02/26/2004
• Est. Priority Date: 08/16/2000
• Status: Active Grant

• Current Assignee: Materials and Separation Technology International Limited
• Original Assignee: Materials and Separation Technology International Limited
• Inventors: Tennison, Stephen Robert, Sowerby, Beverley
• Granted Patent: US 7,544,437 B2
• Time in Patent Office: Days
• US Class Current: 429/44
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 4/8626 characterised by the form
• CPC Class Codes: H01M 4/8807 Gas diffusion layers
• CPC Class Codes: H01M 4/8817 Treatment of supports before application of the catalytic active composition coated porous composites H01M8/0245
• CPC Class Codes: H01M 8/0234 Carbonaceous material
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1007 with both reactants being gaseous or vaporised H01M8/12 takes precedence
• CPC Class Codes: H01M 8/2457 with both reactants being gaseous or vaporised
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

An improved fuel cell structure uses a first sheet of carbon fibres separated by an electrolyte from a second sheet f carbon fibres. A fuel cell catalyst is coated on the outside of the fibres and the fuel passed down one seat of fibres and oxygen or air passed down the second sheet of fibres.

Claims

1. A fuel cell which comprises a first hollow electrically conductive gas permeable fibre which is coated on the outside with a fuel cell catalyst and which has a means to enable a fuel vapour or gas to be passed down the inside of the fibre and a second hollow electrically conductive gas permeable fibre which is coated on the outside with a fuel cell catalyst and which has a means to enable oxygen or an oxygen containing gas to be passed down the inside of the fibre, the first and second carbon fibres being separated by an electrolyte medium.

2. A fuel cell as claimed in claim 1 in which the electrolyte medium is a solid polymer electrolyte.

3. A fuel cell as claimed in claim 1 in which the electrolyte medium is a liquid or gel electrolyte.

4. A fuel cell as claimed in claim1, 2 or 3 in which there are a plurality of first and second hollow electrically conductive gas permeable fibres arranged with all the first hollow electrically conductive gas permeable fibres arranged side by side, so as to form a first sheet of the fibres, and with the second hollow electrically conductive gas permeable fibres similarly arranged to form a second sheet of the second hollow electrically conductive gas permeable fibres, with the fibres in each adjacent sheet at an angle to each other.

5. A fuel cell as claimed in claim 4 in which the fibres in each adjacent sheet are substantially orthogonal to each other.

6. A fuel cell as claimed in claim 4 or 5 in which the electrically conductive gas permeable fibres in each sheet are aligned with their axes substantially parallel.

7. A fuel cell as claimed in any one of claims 1 to 6 in which there is electrically insulating mesh separating the first and second fibres.

8. A fuel cell as claimed in any one of the preceding claim in which the first electrically conductive gas permeable fibre sheet (anode) and the second electrically conductive gas permeable fibre sheet (cathode) are separated by a fuel cell proton conducting layer which is positioned in between them.

9. A fuel cell as claimed in any one the preceding claims in which the individual fibres in each sheet are electrically connected to each other at one or both ends.

10. A fuel cell as claimed in claim 9 in which the individual fibres in each sheet are electrically connected by means of a connecting block which contains a metal mesh that provides the means for making the external electrical connection to the cell.

11. A fuel cell which comprises a multilayered block formed of a plurality of number of alternate sheets as claimed in any one of the preceding claims in which the first sheet comprises a layer of the first electrically conductive gas permeable fibres forming cathodes and the second sheet comprises a layer of the second electrically conductive gas permeable fibres forming the anodes with the fibres in each alternate layer substantially orthogonal to each other

12. A fuel cell as claimed in claim 11 in which the cathode fibres are connected together and the anode fibres are connected together in each block and a plurality of blocks are connected together in series and/or parallel.

13. A fuel cell as claimed in any one of the preceding claims in which the outside diameter of the individual hollow fibres is from 80 to 500 microns.

14. A fuel cell as claimed in claim 13 in which the outside diameter of the hollow fibres is from 100 to 300 microns.

15. A fuel cell as claimed in any one of the preceding claims in which the wall thickness of the hollow carbon fibre is from 10 to 100 microns.

16. A fuel cell as claimed in any one of the preceding claims in which the wall thickness of the hollow carbon fibre is from 20 to 100 microns.

17. A fuel cell as claimed in any one of the preceding claims in which the inside diameter of the individual fibres is from 70 to 250 microns.