Patent ID: 7285354

Claim:
A method of producing an electrode of a polymer electrolyte membrane fuel cell comprising a polymer electrolyte membrane, an electrode contacting the polymer electrolyte membrane and including a gas diffusion layer and a catalyst layer provided in contact with the polymer electrolyte membrane, and a separator provided in contact with the gas diffusion layer, said method comprising: (a) providing a polymer film; (b) providing a gas diffusion layer; (c) providing a paste including at least a carbon powder having a catalyst supported thereon mixed in a solvent, (d) spreading said paste over said polymer film to provide a coated support, (e) drying the coated support to evaporate said solvent to form a catalyst layer on said support, (f) layering said gas diffusion layer and said catalyst layer with one another to form an electrode; and (g) controlling a cracking occupation area on the electrode to a predetermined tolerance by controlling at least one of (a) a thickness of said catalyst layer formed in step (e), (b) a kind of carbon in said carbon powder having the catalyst supported thereon, and (c) a drying rate of said coated support in step (e).