Patent ID: 6730426
Filing Date: 2004-05-04
Classification: H01M,Y02E

Abstract:
A fuel cell stack comprising:a plurality of polymer electrolyte membrane fuel cell units having an anode electrode, a cathode electrode and a polymer electrolyte membrane disposed between said anode electrode and said cathode electrode; a bi-polar separator plate comprising graphite and having a centrally disposed active region substantially coextensive with said electrodes separating each of said fuel cell units between said anode electrode and said cathode electrode of adjacent said fuel cell units and comprising distribution means for providing an oxidant to said cathode electrode, a fuel gas to said anode electrode and a cooling medium between said anode electrodes and said cathode electrodes and having a substantially flat peripheral sealing region on each face extending around said centrally disposed active region; and gasket means for preventing said oxidant, said fuel gas and said cooling medium from mixing, said gasket means comprising a gasketing material consisting essentially of silicone disposed directly on said substantially flat peripheral sealing region on each said face of said bi-polar separator plate, said gasket material contacting said bi-polar separator plate and said polymer electrolyte membrane, thereby forming a peripheral silicone seal.