US 7,572,541 B2
Fuel cell
Tomoaki Arimura, Ome (Japan)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan)
Filed on Nov. 22, 2005, as Appl. No. 11/285,666.
Claims priority of application No. 2004-376449 (JP), filed on Dec. 27, 2004.
Prior Publication US 2006/0141297 A1, Jun. 29, 2006
Int. Cl. H01M 4/86 (2006.01)
U.S. Cl. 429—42  [429/44; 568/6] 6 Claims
OG exemplary drawing
 
1. A fuel cell comprising a unit cell having a membrane-like electrode unit including an electrolyte membrane, a fuel electrode having a methanol aqueous solution supplied thereto as a fuel, and consisting essentially of a catalyst layer and a diffusion layer, which are formed in the order mentioned on one surface of the electrolyte membrane, and an air electrode having an oxidizing gas supplied thereto, and consisting essentially of a catalyst layer and a diffusion layer, which are formed in the order mentioned on the other surface of the electrolyte membrane,
wherein the diffusion layer of at least the fuel electrode among the fuel electrode and the air electrode includes a carbon paper prepared by laminating carbon fibers, and a water repellent polymer represented by general formula (I) given below is arranged to cover the surface of the carbon fiber of the carbon paper or is loaded in the clearance among the carbon fibers of the carbon paper:

OG Complex Work Unit Drawing
where R1 denotes a divalent to tetravalent element, R2 denotes a hydrocarbon functional group or an aromatic functional group, and n denotes an integer of 2 or more.