Abstract: A method for reducing the probability of an air/hydrogen front in a fuel cell stack is disclosed that includes closing anode valves for an anode side of the fuel cell stack to permit a desired quantity of hydrogen to be left in the anode side upon shutdown and determining a schedule to inject hydrogen during the time the fuel cell stack is shutdown. The pressure on an anode input line is determined and a discrete amount of hydrogen is injected into the anode side of the stack according to the determined schedule by opening anode input line valves based on the determined pressure along the anode input line so as to inject the hydrogen into the anode side of the stack.

Abstract: A seal structure is disclosed for forming a substantially fluid tight seal between a UEA and a plate of a fuel cell system, the seal structure including a sealing member formed in one fuel cell plate, a seal support adapted to span feed area channels in an adjacent fuel cell plate, and a seal adapted to cooperate with a UEA disposed between the fuel cell plates, the sealing member, and the seal support to form a substantially fluid tight seal between the UEA and the one fuel cell plate. The seal structure militates against a leakage of fluids from the fuel cell system, facilitates the maintenance of a velocity of a reactant flow in the fuel cell system, and a cost thereof is minimized.

Abstract: A model uses various operating characteristics of a fuel cell to predict the relative humidity profile that is occurring within the fuel cell as a function of the reaction progress. The model is used to predict the relative humidity profile that will occur in response to changes to one or more of the operating characteristics of the fuel cell. A high frequency resistance of the fuel cell can also be used as a measure that is indicative of the humidity within the fuel cell. The model and/or the high frequency resistance can be used in a closed-loop feedback system to control the operation of the fuel cell to maintain the humidification of the MEA and fuel cells within a desired range to achieve a desired fuel cell performance.

Abstract: A fluid distribution insert adapted to be received within an inlet header of a fuel cell assembly is disclosed. The fluid distribution insert includes a wedge section having a first end and a second end. The wedge section forms a fluid flow path between a surface forming the inlet header and the wedge section, wherein the fluid flow path receives a fluid therein and delivers the fluid to a plurality of fuel cells of the fuel cell assembly. The wedge section minimizes a cross-sectional area of the fluid flow path adjacent the second end of the wedge section to maintain a substantially constant fluid velocity along a length of the inlet header.

Abstract: A membrane humidifier for a fuel cell with a wet side plate having a plurality of flow channels formed therein and a dry side plate having a plurality of flow channels formed therein, the flow channels of the wet side plate adapted to facilitate a flow of a wet gas therethrough and the flow channels of said dry side plate adapted to facilitate a flow of a dry gas therethrough, wherein a pressure drop in the humidifier is minimized and a humidification of a proton exchange membrane in the fuel cell is optimized.

Abstract: A fuel cell system that enables an assisted anode purge upon start-up is provided. The fuel cell system includes a fuel cell stack having a plurality of fuel cells with anodes and cathodes. The fuel cell stack has an anode supply manifold and an anode exhaust manifold in fluid communication with the anodes. The fuel cell system further includes a suction device in fluid communication with at least one of the anode supply manifold and the anode exhaust manifold. The suction device adapted to selectively draw a partial vacuum on the fuel cell stack during a start-up of the fuel cell system. Methods for starting the fuel cell system are also provided.

Abstract: A method for filling a fuel cell anode supply manifold with hydrogen prior to a start-up operation to facilitate a substantially even hydrogen distribution across the fuel cell is disclosed. The anode supply manifold is in fluid communication with a source of hydrogen. A first valve in fluid communication with the anode supply manifold and a second valve in fluid communication with an anode exhaust manifold are initially in a closed position while hydrogen is supplied to the anode inlet conduit to pressurize the fuel cell stack. The first valve is then opened to purge at least a portion of a fluid from the anode supply manifold to facilitate a filling of the manifold with hydrogen.

Abstract: A membrane humidifier for a fuel cell system is disclosed wherein the membrane humidifier includes a plurality of membrane layers, a first pair of spaced apart sealing bars disposed between a first membrane layer and a second membrane layer adjacent to perimeter edges thereof to form a first flow channel, a second pair of spaced apart sealing bars disposed between the second membrane layer and a third membrane layer adjacent to perimeter edges thereof to form a second flow channel, and a plurality of supports, wherein a first support is disposed adjacent the second planar layer and extending between the second pair of spaced apart sealing bars, and a second support is disposed adjacent the third planar layer and extending between the second pair of spaced apart sealing bars.

Abstract: A fuel cell system that enables an assisted anode purge upon start-up is provided. The fuel cell system includes a fuel cell stack having a plurality of fuel cells with anodes and cathodes. The fuel cell stack has an anode supply manifold and an anode exhaust manifold in fluid communication with the anodes. The fuel cell system further includes a suction device in fluid communication with at least one of the anode supply manifold and the anode exhaust manifold. The suction device adapted to selectively draw a partial vacuum on the fuel cell stack during a start-up of the fuel cell system. Methods for starting the fuel cell system are also provided.

Abstract: A bipolar plate assembly for a fuel cell is provided. The bipolar plate assembly includes a first electroformed unipolar plate disposed adjacent a second electroformed unipolar plate. The first and second unipolar plates are bonded by a plurality of localized electrically and thermally conductive plugs by electroplated material deposited within apertures formed in the substrates onto which the unipolar plates are electroformed. A method for forming the bipolar plate assembly is also described.

Abstract: A product includes a fuel cell stack, and an enclosure apparatus sealingly enclosing the fuel cell stack to define a hydrogen chamber between the fuel cell stack and the enclosure apparatus. An operation of the product may include maintaining a positive pressure of hydrogen in the hydrogen chamber.

Abstract: A thermal management device for dissipating thermal energy from a secondary battery cell includes a first plate defining a first channel and a second channel spaced apart from the first channel, wherein the first plate further defines an inlet port in communication with the first channel and an outlet port in communication with the second channel and spaced opposite the inlet port. The device includes a second plate configured for thermal energy exchange with the cell and disposed in contact with the first plate to define a cross-flow channel, wherein the cross-flow channel interconnects the first and second channels. A thermal management system includes a cell having a first temperature, a fluid having a second temperature that is less than the first temperature, and the device. The fluid is conveyable from the inlet port to the outlet port via the cross-flow channel to thereby dissipate thermal energy from the cell.

Abstract: A method for filling a fuel cell system with a fuel during start-up is disclosed, the method including the steps of providing a fuel cell stack having a plurality of fuels cells, each fuel cell having an active area, the fuel cell stack including an anode supply manifold and an anode exhaust manifold, the anode supply manifold and in fluid communication with a source of fuel; providing an anode sub-system in fluid communication with an anode side of the fuel cell stack; and supplying the fuel to the fuel cell stack substantially uniformly and substantially simultaneously to compress any fluids in the fuel cell stack into a volume between an end of each active area adjacent to the anode exhaust manifold and an outlet of the anode sub-system.

Abstract: A fluid distribution insert adapted to be received within an inlet header of a fuel cell assembly is disclosed. The fluid distribution insert includes a hollow insert with a first end and a second end. An inlet is formed at the first end of the hollow insert in fluid communication with a source of a reactant gas and adapted to receive the reactant gas therein. A plurality of outlets is formed intermediate the first end and the second end. A plurality of flow channels is formed in the hollow insert providing fluid communication between the inlet and the outlets to deliver the fluid to a plurality of fuel cells of the fuel cell assembly, wherein a total flow volume and flow resistance of each of the flow channels is substantially the same to provide for a substantially simultaneous delivery of the reactant gas to the fuel cells.

Abstract: A fuel cell system is disclosed with a fuel cell stack having a plurality of fuel cells, the fuel cell stack including an external electrical circuit adapted to control current from the fuel cell stack, a sensor for measuring at least one of an environmental condition affecting the fuel cell stack and a characteristic of the fuel cell stack, wherein the sensor generates a sensor signal representing a measurement of the sensor, and a processor for receiving the sensor signal, analyzing the sensor signal, and controlling an adaptive load applied to the external electrical circuit based upon the analysis of the sensor signal.

Abstract: A fluid distribution insert adapted to be received within an inlet header of a fuel cell assembly. The fluid distribution insert includes a hollow insert with a first end and a second end. An inlet is formed at the first end of the hollow insert in fluid communication with a source of a reactant gas and adapted to receive the reactant gas therein. An outlet is formed intermediate the first end and the second end. The outlet is adapted to deliver the reactant gas to a plurality of fuel cells of the fuel cell assembly, wherein the hollow insert delivers the reactant gas to the fuel cells in a substantially simultaneous and uniform manner.

Abstract: A model uses various operating characteristics of a fuel cell to predict the relative humidity profile that is occurring within the fuel cell as a function of the reaction progress. The model is used to predict the relative humidity profile that will occur in response to changes to one or more of the operating characteristics of the fuel cell. A high frequency resistance of the fuel cell can also be used as a measure that is indicative of the humidity within the fuel cell. The model and/or the high frequency resistance can be used in a closed-loop feedback system to control the operation of the fuel cell to maintain the humidification of the MEA and fuel cells within a desired range to achieve a desired fuel cell performance.

Abstract: A fuel cell component including a body disposed along a plane and having a boundary past which a reactant and water flows is provided. The boundary has a discontinuous edge adapted to militate against a pinning of the water at the edge. The fuel cell component may be a bipolar plate having a port hole with the discontinuous edge. The fuel cell component may be a subgasket for a fuel cell having a boundary with the discontinuous edge. The discontinuous edge facilitates a transportation of water from an upper surface of the fuel cell component to a lower surface of the fuel cell component.

Abstract: A fuel cell having a pair of bipolar plates is provided. Each of the bipolar plates has a nested active area and a non-nested feed area which also may serve as active area. An electrolyte membrane is disposed between a pair of electrodes and a pair of diffusion medium layers. Each of the diffusion medium layers is disposed adjacent the nested active areas and non-nested feed areas of the bipolar plates. A porous, electrically conductive spacer is disposed between one of the diffusion medium layers and one of the bipolar plates. A fuel cell stack having the fuel cell is also provided.

Abstract: A passive water drain for removal of water from a fuel cell system is disclosed, the drain including a main body having a cavity formed therein, an interior element, and a hydrophilic porous media. The passive water drain is adapted to simplify the anode reactant recycler, eliminate the need for bypass valve systems used to remove water from the cathode exhaust, and eliminate the need for condensate draining systems used for compressed air entering the cathode.