Abstract: A method of making a reconstructed electrode having a plurality of nanostructured thin catalytic layers is provided. The method includes combining a donor decal comprising at least one nanostructured thin catalytic layer on a substrate with an acceptor decal comprising a porous substrate and at least one nanostructured thin catalytic layer. The donor decal and acceptor decal are bonded together using a temporary adhesive, and the donor substrate is removed. The temporary adhesive is then removed with appropriate solvents. Catalyst coated proton exchange membranes and catalyst coated diffusion media made from the reconstructed electrode decals having a plurality of nanostructured thin catalytic layers are also described.

Abstract: An anode reactant recycling system for a fuel cell is disclosed, the system including a hollow main body, a bleed conduit, an injector, a water separator, and a hydrophilic porous media. The anode reactant recycling system for a fuel cell is adapted to minimize a required number of components, eliminate the need for the anode heat exchanger, use a single valve for removal of condensate and reactant byproducts from the anode reactant recycling system, and provide an upstream volume for startup pressurization.

Abstract: A fuel processor system capable of circulating fuel processor system gases, e.g. reformate, anode exhaust, and/or combustor exhaust, through a fuel processor provides advantages. The system fuel cells discharge hydrogen-containing anode exhaust and oxygen-containing cathode exhaust, The fuel processor converts hydrogen-containing fuel to hydrogen-containing reformate to fuel the fuel cells. A catalytic combustor coupled with a vaporizer reactor is positioned in series downstream from the fuel cells. A bypass passage connects an outlet of at least one of the fuel processor, the fuel cells, the catalytic combustor, and the vaporizer reactor to the inlet of the fuel processor. The bypass passage is operable to circulate a fuel processor system gas to the inlet of the fuel processor.

Abstract: A fuel cell including a water blocking layer positioned between anode gas flow channels and a gas diffusion media. The blocking layer prevents water from propagating through the gas diffusion media layer and entering the anode flow channels, while allowing gas from the flow channels to flow through the diffusion media layer to the membrane. A water accumulation channel can be provided around the perimeter of the gas diffusion media layer where blocked water is accumulated, and allowed to expand during cell freezing. A porous capillary wick can be provided in the accumulation channel for wicking water to the inlet end of the flow channels where it is used to humidify the anode gas coming into the fuel cell. The wick can have a tapered configuration so that it has a larger diameter at the gas input end of the flow channels.

Abstract: Methods for starting a fuel cell system are provided. In one embodiment, the method includes providing hydrogen to an inlet of an anode of the fuel cell pressurizing the anode to a pressure; determining whether a blocked cell condition exists; if a blocked cell condition exists, if no blocked cell condition exists, initiating a normal start sequence, alternately reducing the pressure of the anode and increasing the pressure of the anode until an exit condition exists, the exit condition selected from a voltage of the fuel cell being stable, or a temperature of the fuel cell being greater than about 0° C., or both, and when the exit condition exists, initiating the normal start sequence.

Abstract: A method and device for operating a fuel cell system. A recirculation loop coupled to a fuel cell cathode ensures that fluids passing through the cathode are recycled, thereby enabling reaction between residual oxygen in the recycled fluid and fuel that has been introduced into the recirculation loop until substantially all of the oxygen is reacted, leaving a substantially oxygen-free, predominantly nitrogen compound in the cathode and related flowpath. Thereafter, this compound can be redirected to purge the remaining residual hydrogen resident in the fuel cell's anode and related flowpath. While the present invention is usable during any period of system operation, it is especially valuable for operational conditions associated with starting up and shutting down a fuel cell system to inhibit the formation of high voltage potentials that could otherwise damage fuel cell catalysts or catalysts supports.

Abstract: Clearance gaps in the inactive feed regions of a fuel cell stack are controlled by non-bonded, non-nested bipolar plates to provide reactant flow uniformity and pressure within fuel cells and fuel cell stacks utilizing nested bipolar plates in the active feed regions and non-nested bipolar plates in the inactive feed regions.

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 diffusion media and micro-porous media combination for a fuel cell. A diffusion layer is composed of a diffusion media and has a first (electrode) side and an opposite second (flowfield) side, wherein at least one of the first and second sides has a geometric pattern formed therein comprising a multiplicity of mutually spaced apart regions. A micro-porous media fills the multiplicity of regions and a micro-porous layer composed of the micro-porous media is continuously applied to the first surface.

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.

Abstract: Processes to shut down a fuel cell system are described. In one implementation (300), a load (215) is cyclically engaged and disengaged across a fuel cell stack (205) so as to deplete the fuel available to the system's fuel cells (205). Voltage and/or current thresholds may be used to determine when to engage and disengage the load (215) and when to terminate the shutdown operation. In another implementation (500), a variable load (405) is engaged and adjusted so as to deplete the fuel available to the system's fuel cells (205). As before, voltage and/or current thresholds may be used to determine when to adjust the load (405) and when to terminate the shutdown process. In still another implementation, a load (215 or 405) may be periodically engaged and disengaged during some portion of the shutdown process and engaged but adjusted during other portions of the shutdown process.

Abstract: Between adjacent MEA's is a bipolar plate assembly having a first sub-plate with a flow channel which is open to the anode side of the one of the MEA's. A second sub-plate has a flow channel which is open to the cathode side of the adjacent MEA. The sub-plates are nested together to form a coolant flow channel between the sub-plates. The coolant flow path has a height dimension wherein the distance between the adjacent MEA's is substantially unaffected by the height dimension of the coolant flow path. A method of manufacturing a bi-polar plate assembly includes forming a closed coolant flow channel between the sub-plates by nesting the sub-plates together. A method of operating a fuel cell includes passing the coolant through a flow path having a height dimension which is substantially aligned with the height dimension of the hydrogen flow path, the oxygen flow path, or both.

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 fuel cell system that includes an over-arching algorithm for providing a strategy that reduces relative humidity cycling of the cathode outlet gas between wet and dry operation to extend the useful life of the membrane. The algorithm receives sensor signals indicative of operating parameters of the fuel cell system. The algorithm maintains a cathode exhaust gas relative humidity in a wet operating mode if the operating parameters of the fuel cell system are able to sustain the cathode gas relative humidity above a first predetermined value, and maintains the cathode exhaust gas relative humidity in a dry operating mode if the operating parameters of the fuel cell system are able to sustain the cathode gas relative humidity below a second predetermined value.

Abstract: A UEA for a fuel cell having an active region and a feed region is provided. The UEA includes an electrolyte membrane disposed between a pair of electrodes. The electrolyte membrane and the pair of electrodes is further disposed between a pair of DM. The electrolyte membrane, the pair of electrodes, and the DM are configured to be disposed at the active region of the fuel cell. A barrier film coupled to the electrolyte membrane is configured to be disposed at the feed region of the fuel cell. The dimensions of the electrolyte membrane are thereby optimized. A fuel cell having the UEA, and a fuel cell stack formed from a plurality of the fuel cells, is 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: The present invention includes an integrated fuel processor subsystem incorporating a thermal combustor, a catalytic combustor, a quasi-autothermal reactor (QATR) and a air-fuel-steam (AFS) mixer to provide a range of operating modes exhibiting performance between that of a pure steam reformer and a pure autothermal reformer to increase the flexibility of the fuel processor to handle transient system demands such as cold starts, suppress emissions and carbon formation and improve efficiency.

Abstract: A method and device for operating a fuel cell system. A recirculation loop coupled to a fuel cell cathode ensures that fluids passing through the cathode are recycled, thereby enabling reaction between residual oxygen in the recycled fluid and fuel that has been introduced into the recirculation loop until a reduced voltage level across the fuel cell is achieved. Attainment of the reduced voltage level indicates that the recycled fluid is substaintially oxygen-free, yielding an inerting fluid. Thereafter, this compound, followed by air, or air directly can be used to purged the fuel cell's anode and relating flowpath during system shutdown. Similarly during system startup, hydrogen can then be introduced into the fuel cell's anode and then air into the cathode and related flowpath for normal operation. The placemet of a purge valve allows the anode to be purged with air without re-introducing air into the cathode.

Abstract: A fuel cell comprising anode and cathode flow field plates having a multitude of flow channels separated by land features wherein the land features of the anode side are wider than the land features of the cathode side is disclosed. In fuel cells, the flow field plate arrangement of the present invention provides higher power (lower cost per kW), improved durability, and less stringent assembly alignment.

Abstract: A fuel cell comprising anode and cathode flow field plates having a multitude of flow channels separated by land features wherein the land features of the anode side are wider than the land features of the cathode side is disclosed. In fuel cells, the flow field plate arrangement of the present invention provides higher power (lower cost per kW), improved durability, and less stringent assembly alignment.