Abstract: A composite flow field element, such as a separator plate used in a high temperature air-cooled fuel cell assembly, preferably includes a metal sheet substrate of non-uniform thickness, such as a mesh, and flexible graphite layers bonded to the metal mesh substrate by an electrically conductive bonding agent.

Abstract: An improved method of manufacturing a PEM fuel cell collector plate is disclosed. During molding a highly conductive polymer composite is formed having a relatively high polymer concentration along its external surfaces. After molding the polymer rich layer is removed from the land areas by machining, grinding or similar process. This layer removal results in increased overall conductivity of the molded collector plate. The polymer rich surface remains in the collector plate channels, providing increased mechanical strength and other benefits to the channels. The improved method also permits greater mold cavity thickness providing a number of advantages during the molding process.

Abstract: An improved molding process provides highly conductive polymer composite parts have bulk conductivity over 10 S/cm. This conductivity is particularly useful in collector plate for use in fuel cells. The process can include compounding of a mixture of conductive filler with a polymer binder, extruding the mixture after the binder is plasticized to make pellets. The pellets can then be introduced to a dual temperature feed container of an injection molding machine and injected under high pressure and velocity into the mold cavity. The resulting parts, and particularly collector plates can be made economically and provide a high conductivity while maintaining strength and chemical resistance properties.

Abstract: An improved molding composition is provided for compression molding or injection molding a current collector plate for a polymer electrolyte membrane fuel cell. The molding composition is comprised of a polymer resin combined with a low surface area, highly-conductive carbon and/or graphite powder filler. The low viscosity of the thermoplastic resin combined with the reduced filler particle surface area provide a moldable composition which can be fabricated into a current collector plate having improved current collecting capacity vis-a-vis comparable fluoropolymer molding compositions.