Fuel cells based on hollow conductive carbon fibres

Abstract

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

1 - 17 . (canceled) 
     
     
         18 - 29 . (canceled) 
     
     
         30 . A fuel cell which comprises a plurality of first hollow electrically conductive gas permeable carbon fibres which are coated on the outside with a fuel cell catalyst and which have a means to enable a fuel vapour or gas to be passed down the inside of the fibre and a plurality of second hollow electrically conductive gas permeable carbon fibres which are coated on the outside with a fuel cell catalyst and which have a means to enable oxygen or an oxygen containing gas to be passed down the inside of the fibber with the first hollow electrically conductive gas permeable carbon fibres arranged side by side, so as to form a first sheet of the fibres, and with the second hollow electrically conductive gas permeable carbon fibres arranged side by side to form a second sheet of the fibres, with the fibres in each adjacent sheet at an angle to each other and in which first electrically conductive has permeable fibber sheet (anode) and the second electrically conductive has permeable fibber sheet (cathode) are separated by a fuel cell proton conducting layer which is positioned in between them. 
     
     
         31 . A fuel cell according to  claim 30  in which the individual fibers in each sheet are electrically connected to each other at one or both ends. 
     
     
         32 . A fuel cell according to  claim 31  in which the individual fibers in each sheet are electrically connected by means of a connecting block which contains a metal mesh that provides the means for making an external connection to the cell. 
     
     
         33 . A fuel cell according to  claim 30  which comprises a multi-layered block.formed of a plurality of alternate sheets in which the first sheet comprises a layer of the first electrically conductive gas permeable carbon fibres forming cathodes and the second sheet comprises a layer of the second electrically conductive gas permeable carbon fibres forming the anodes with the fibres in each alternate layer substantially orthogonal to each other. 
     
     
         34 . A fuel cell according to  claim 30  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. 
     
     
         35 - 44 . (canceled) 
     
     
         45 . A fuel cell which comprises two electrodes separated by an electrolyte medium, wherein:
 (a) the first electrode comprises at least one first hollow electrically conductive gas permeable carbon fibre, the fibre consisting essentially of carbon 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;   (b) the second electrode comprises at least one second hollow electrically conductive gas permeable carbon fibre, the fibre consisting essentially of carbon 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;   (c) the first and second carbon fibres being separated by the electrolyte medium.   
     
     
         46 . A fuel cell according to  claim 45  in which the electrolyte medium is a solid polymer electrolyte. 
     
     
         47 . A fuel cell according to  claim 45  in which the electrolyte medium is a liquid or gel electrolyte. 
     
     
         48 . A fuel cell according to  claim 45  in which the electrically conductive gas permeable fibres in which sheet are aligned with their axes substantially parallel. 
     
     
         49 . A fuel cell according to  claim 45  in which there is electrically insulating mesh separating the first and second fibres. 
     
     
         50 . A fuel cell according to  claim 45  in which the outside diameter of the individual hollow fibres is from 80 to 500 microns. 
     
     
         51 . A fuel cell according to  claim 45  in which the wall thickness of the hollow carbon fibre is from 100-300 microns. 
     
     
         52 . A fuel cell according to  claim 45  in which the wall thickness of the hollow carbon fibre is from 10-100 microns. 
     
     
         53 . A fuel cell according to  claim 45  in which the wall thickness of the hollow carbon fibre is from 20-100 microns. 
     
     
         54 . A fuel cell according to claim  55  in which the inside diameter of the individual fibre is from 70 to 250 microns.