Abstract: A method for preparing a bipolar plate assembly for a fuel cell stack is provided. The method first includes the steps of providing a first unipolar plate having a first active area with a plurality of channels formed on a first inner surface thereof, and a second unipolar plate having a second active area with a plurality of lands formed on a second inner surface thereof. The first unipolar plate and the second unipolar plate are aligned to dispose the first active area adjacent the second active area. A first pressure is then applied to the first and second active areas to pre-nest the first active area and the second active area. The perimeters of the first and second unipolar plates are then joined. A clamping fixture and associated method for assembling the bipolar plate assembly is also provided.

Abstract: A method for preparing a bipolar plate assembly for a fuel cell stack is provided. The method first includes the steps of providing a first unipolar plate having a first active area with a plurality of channels formed on a first inner surface thereof, and a second unipolar plate having a second active area with a plurality of lands formed on a second inner surface thereof. The first unipolar plate and the second unipolar plate are aligned to dispose the first active area adjacent the second active area. A first pressure is then applied to the first and second active areas to pre-nest the first active area and the second active area. The perimeters of the first and second unipolar plates are then joined. A clamping fixture and associated method for assembling the bipolar plate assembly is also provided.

Abstract: The present invention is directed to mitigating overuse of limited membrane regions in electrochemical conversion assemblies, particularly under cold start conditions. In accordance with one embodiment of the present invention, the anode and/or cathode flowfield plates of an electrochemical conversion assembly are configured such that the fluid header region defines an anode fluid header, a cathode fluid header, and a coolant fluid header configured such that a feed region of the plate defines an array of substantially linear fluid channels extending from an acutely angled header/feed interface defined on the plate to a feed/active interface defined across the entire active area of the plate.

Abstract: The present invention is directed to mitigating overuse of limited membrane regions in electrochemical conversion assemblies, particularly under cold start conditions. In accordance with one embodiment of the present invention, the anode and/or cathode flowfield plates of an electrochemical conversion assembly are configured such that the fluid header region defines an anode fluid header, a cathode fluid header, and a coolant fluid header configured such that a feed region of the plate defines an array of substantially linear fluid channels extending from an acutely angled header/feed interface defined on the plate to a feed/active interface defined across the entire active area of the plate.

Abstract: A seal configuration is provided for a fuel cell stack, including a first bipolar plate and a second bipolar plate, each disposed on opposite sides of a membrane electrode assembly. The seal configuration includes a first sub-gasket adhered to a recess region of the first bipolar plate and a second sub-gasket adhered to a recess region of the second bipolar plate wherein the first and second sub-gaskets are disposed on opposite sides of the membrane electrode assembly. A seal member is disposed in the recessed regions of the first and second bipolar plates and between the first and second sub-gaskets. The seal configuration minimizes the size of the bypass regions around the seal perimeter and provide better control of the positions of all components during assembly of the fuel cell stack. The approach also reduces sensitivity to ambient relative humidity variations and reduces manufacturing costs by eliminating the need for humidity control in the production area.

Abstract: The present invention discloses a stamped bridge member that defines a flow path between a header and a flow field on a fuel cell plate. The bridge member provides a support surface on which a seal can be positioned to seal the plate against adjacent plates or MEAs. The fuel cell plates can be stamped plates with two surfaces each having flow fields thereon. The flow fields maintain a fluid flowing between a supply header and a return header on a single surface of the plate. The ends of the flow fields can taper relative to the supply and return apertures to provide for a desired flow distribution through the flow field.