Abstract: A sensor plate for measuring current and/or temperature distribution of an operating fuel cell. The sensor plate has a circuit board interposed between an anode flow field plate and a cathode flow field plate of the fuel cell. A flow field plate is segmented into a plurality of electrically isolated regions without disrupting the flow field of the plate. The circuit board has an array of resistors and/or thermistors mounted to it wherein each resistor and/or thermistor is associated with one of the electrically isolated regions of the segmented plate. The current distribution of the electrically isolated regions of the fuel cell is calculated by using the voltage drop across the resistors and the known resistance values of the resistors mounted to the circuit board.

Abstract: Various devices and methods for achieving electrochemical energy conversion are presented. In accordance with one embodiment, an energy conversion cell is configured to enable the first and second reactant supplies to communicate selectively with first and second catalytic electrodes of the cell. The selective communication of the first and second reactant supplies with the first and second catalytic electrodes may be attributable to alteration of the reactant supply flow paths or to movement of the first and second catalytic electrodes.

Abstract: Various devices and methods for achieving electrochemical energy conversion are presented. In accordance with one embodiment, an energy conversion cell is configured to enable the first and second reactant supplies to communicate selectively with first and second catalytic electrodes of the cell. The selective communication of the first and second reactant supplies with the first and second catalytic electrodes may be attributable to alteration of the reactant supply flow paths or to movement of the first and second catalytic electrodes.

Abstract: A bipolar plate for use with a fuel cell is provided including an electrically conductive foam as a coolant layer between thin metal foil layers. The thin metal foil layers are provided with serpentine flow field patterns on a surface thereof.

Abstract: A sensor plate for measuring current and/or temperature distribution of an operating fuel cell. The sensor plate has a circuit board interposed between an anode flow field plate and a cathode flow field plate of the fuel cell. A flow field plate is segmented into a plurality of electrically isolated regions without disrupting the flow field of the plate. The circuit board has an array of resistors and/or thermistors mounted to it wherein each resistor and/or thermistor is associated with one of the electrically isolated regions of the segmented plate. The current distribution of the electrically isolated regions of the fuel cell is calculated by using the voltage drop across the resistors and the known resistance values of the resistors mounted to the circuit board.

Abstract: Method and apparatus for cooling a fuel cell stack. The cooling system uses vaporization cooling of the fuel stack and supersonic vapor compression of the vaporized coolant to significantly increase the temperature and pressure of the liquid coolant flowing through a heat exchanger. By increasing the heat rejection temperature of the coolant delivered to the heat exchanger, the heat transfer area of the heat exchanger can be reduced and the mass flow rate of coolant can also be reduced. The increased fluid pressure is used to circulate the coolant through the cooling system, thereby eliminating the circulation pump associated with conventional systems.

Abstract: A proton exchange membrane fuel cell including a membrane electrode assembly comprising a proton transmissive membrane, a catalytic anode layer on one face of the membrane, and a catalytic cathode layer on the other face of the membrane. The fuel cell further includes a gas distribution layer on each of the cathode and anode layers defining a gas flow field extending over each of the catalytic layers. The membrane electrode assembly has a convoluted configuration whereby to increase the ratio of membrane area to planar fuel cell area and thereby increase the electrical output of the fuel cell for a given planar area size fuel cell. The convoluted configuration of the membrane electrode assembly also facilitates the division of the gas distribution layers into separate parallel channels thereby allowing the use of an inexpensive foam material for the gas distribution layers irrespective of the inherent variations in porosity of foam materials.

Abstract: A proton exchange membrane fuel cell comprising a proton transmissive membrane, a catalytic anode layer on one face of the membrane, a catalytic cathode layer on the other face of the membrane, and a gas distribution layer on each of the cathode and anode layers defining a gas flow field extending over each of the catalytic layers. Each of the gas distribution layers comprises a layer of open cell conductive foam material which is divided into a plurality of generally parallel segments extending from one edge of the fuel cell to an opposite edge of the fuel cell whereby to define a plurality of generally parallel porous reactant paths extending across each catalytic layer. The segments may be defined by selectively varying the porosity of the foam material or selectively varying the thickness of the foam material.

Abstract: A fuel cell of the type having a membrane electrode assembly (MEA) interdisposed between a pair of bipolar plate assemblies. The MEA may have a convoluted configuration to maximize the effective surface area of the MEA for a given planar area. Each bipolar plate assembly includes a gas distribution layer of open cell conductive foam material which is divided into a plurality of generally parallel segments to define a plurality of generally parallel porous reactant paths. The segments are defined by selectively varying the porosity of the foam material and/or selectively varying the thickness of the foam material. The foam material may be a conductive graphite foam media or a conductive metallic foam media. Each bipolar plate assembly further includes a non-porous, conductive separator plate. The bipolar plate assembly distributes the reactant gases delivered via a manifold structure across the face of the MEA.