Abstract: A fuel cell system comprising a passive end cell heater for heating an end cell or cells within a fuel cell stack is disclosed. The fuel cell system comprises a fuel cell stack and a resistive heatable element connected in parallel to the fuel cell stack, wherein the resistive heatable element is adapted to heat an end cell of the fuel cell stack. A method for heating an end cell in a fuel cell stack is also disclosed.

Abstract: Disclosed are reactant feed apparatus for liquid-fueled direct feed fuel cells, including miniaturized versions thereof. More specifically, disclosed is a fuel flow device for delivering liquid fuel to such direct feed fuel cells. The fuel flow device comprises a fuel flow-routing device and an enclosure/partition assembly containing the liquid fuel to be delivered. When the fuel flow device is fluidly connected to the fuel cell, it operates to deliver the liquid fuel to an anode flow field thereof by using the pressurized anodic exhaust gases exiting therefrom as the source of power for pumping the liquid fuel from the enclosure into the fuel cell.

Abstract: A compact, multitube steam reformer converts a fuel into a reformate stream comprising hydrogen. In one embodiment, the reformer comprises a closed vessel and a burner disposed within the vessel. The burner comprises a start fuel manifold for receiving and distributing a start fuel stream, an oxidant manifold for receiving and distributing an oxidant stream, and a burner fuel manifold for receiving and distributing a burner fuel stream. The oxidant manifold comprises a plurality of oxidant distribution tubes, each having an inlet end and an outlet end, disposed in a separator member. The burner fuel manifold comprises a plurality of burner fuel distribution tubes, each having an inlet end and an outlet end. The burner fuel distribution tubes extend through the start fuel manifold and the oxidant manifold and are fluidly isolated therefrom.

Abstract: Fuel cell system comprising at least one fuel cell which includes an anode compartment and a cathode compartment which are separated from one another by a proton-conducting membrane, further comprising a cathode feeder for delivering oxygen-containing gas to the cathode compartment, an anode feeder for delivering a liquid coolant/fuel mixture to the anode compartment, the anode compartment being disposed in an anode circuit which comprises a gas separator and a pump, and cooling of the coolant/fuel mixture circulating in the anode circuit is effected by the fuel cell which is designed for operation involving water break-through from the anode compartment into the cathode compartment. The evaporation cooling thus achieved in the fuel cell results in cooling of the coolant/fuel mixture at a steady-state operating temperature which is established in the fuel cell as a function of the membrane properties and the speed of the pump, thus obviating the need for any additional cooler in the anode circuit itself.

Abstract: An electric power plant includes an array of fuel cell systems. The fuel cell systems are electrically couplable in series and/or parallel combinations to provide a variety of output powers, output current and/or output voltages. The fuel cell systems are “hot swappable” and redundant fuel cell systems may automatically replace faulty fuel cell systems to maintain output power, current and/or voltage.

Abstract: An electrochemical fuel cell having reactant flow passages with a non-uniform design to increase reactant access to an adjacent fluid distribution layer at the outlet region as compared to the inlet region. In an embodiment, at least one reactant flow passage is narrower at the inlet than at the outlet, with a substantially constant cross-sectional area maintained along its length. Coolant channels may optionally be incorporated in the fluid flow plate to provide increased cooling at the reactant inlet. The plates may vary in thickness and run in counter-flow to improve efficient stacking of the fuel cells in a fuel cell stack with reactant passages of varying depth. In another embodiment, electrically conductive, masking foil covers a portion of at least one reactant flow passage in the inlet region, but does not extend the length of the passage.

Abstract: A fuel cell system, particularly for a motor vehicle, includes (1) at least one fuel cell and (2) a device for supplying at least one fuel cell with hydrogen or a hydrogen-containing gas. Particularly during start-up or a cold start of the system, individual components of the device or at least one fuel cell can be supplied thermal energy with cooling water contained in a cooling water system. The cooling water system is equipped with an insulating device for storing cooling water in a thermally insulated manner.

Abstract: A combined component for afterburning anode exhaust gases from a fuel cell system and for vaporizing educts to be fed to the fuel cell system has an exhaust gas catalyzer for afterburning the anode exhaust gases, with a substantially cylindrical casing having an inlet and an outlet connection disposed coaxially to the long axis of the casing, one on a casing cover and the other on a casing bottom. A first gas-permeable inner tube is disposed coaxially to the long axis of the casing and fixedly joined at the gas inlet end to the casing cover, while a second gas-permeable outer tube which is also disposed coaxially with the long axis of the casing and has a radius rA greater than the radius rI of the inner tube but smaller than the radius rG of the casing. The latter is connected gas-tight to the casing cover at the inlet end. A bulk catalyst is disposed in the area between the inner and the outer tube for the catalytic oxidation of the anode exhaust gas.

Abstract: A fuel cell system comprises a reservoir for cryogenic media and a fuel cell unit containing at least one fuel cell connected to receive fuel from the reservoir. At least a first heat exchanger is provided within a cooling circuit for the fuel cell unit, whereby heat from the first heat exchanger (3) is used, at least indirectly, to provide fuel from the reservoir. A heating circuit for the reservoir, designed to heat and/or vaporize the cryogenic medium via the first heat exchanger, is connected directly to the cooling circuit for the fuel cell unit.

Abstract: A method and apparatus are provided for distributing water produced by the electrochemical reaction to ion-exchange membranes in an array comprising a plurality of electrochemical fuel cell stacks. Water distribution within individual fuel cell stacks within the array is improved to reduce membrane dryness near the oxidant stream inlet and to also reduce saturation of the oxidant stream near the oxidant stream outlet, thereby reducing electrode flooding. The method comprises periodically reversing the oxidant stream flow direction within at least one of the plurality of fuel cell stacks. The apparatus comprises an oxidant stream flow switching device for periodically switching the flow direction of an oxidant stream through an individual fuel cell stack. In one embodiment the apparatus further comprises a water recycler for capturing water from the oxidant exhaust stream and returning the captured water to the oxidant stream when the flow direction is reversed.

Abstract: The invention relates to a mobile device comprising an apparatus for generating electric energy, which is connected to an energy distribution network containing branches to the electric loads. A switching and distribution unit connected to the energy generating system comprises a switch which is arranged upstream from the branches. The loads are connected to the switching and distribution unit by means of flexible conductors with connectors on their ends. Means are provided to ensure that the connectors can only be separated when there is no current.

Abstract: A non-invasive, non-destructive method and system for determining power transistor peak die voltage utilizes values for each of a plurality of parameters determined by measurement of external terminal voltages for any number of switches, such as transistors of an inverter. Stray inductance values are calculated and used with measured current gradient to calculate the peak die voltages for the switches.

Abstract: An electric machine in accordance with the invention includes a stator core having first and second ends and having windings therein with end turns of the windings protruding from the first and second ends of the stator core. A rotor is rotatably positioned within the stator core. A thermal conductor, such as non-laminated aluminum or aluminum alloy ring, is disposed between each stator core end-turn and the housing for conducting heat from the stator core end-turns to the housing, and the cavity between each end-turn and the thermal conductor is filled with a flexible potting material to minimize gap formation caused, for example, by thermal cycling of the engine components.

Abstract: A quick connect fitting is provided for connecting a pressure fluid container to an intake port of a consumer system, such as a fuel cell stack. The fitting includes a solenoid-activated valve for controlling outflow of fluid from the pressure fluid container. The valve is biased to a closed position when no electrical power is supplied to the solenoid. In one embodiment the fitting incorporates a coupling mechanism for removable attachment to the intake part of the consumer system.

Abstract: A gas generating system for a fuel cell system as well as to a method of operating same. In order to provide hydrogen-containing combustible gas as rapidly as possible and to reduce the exhaust gas emissions, for the start of the operation of the gas generating system, at least one catalytic burner is started and the generated heat is used for evaporating a combustion agent and/or water and for the heating-up of an additionally connected partial reforming unit or partial oxidation stage in order to generate a hydrogen-containing gas for the fuel cell unit by reforming or partial oxidation.

Abstract: Non-noble metal transition metal catalysts can replace platinum in the oxidation reduction reaction (ORR) used in electrochemical fuel cells. A RuxSe catalyst is prepared with comparable catalytic activity to platinum. An environmentally friendly aqueous synthetic pathway to this catalyst is also presented. Using the same aqueous methodology, ORR catalysts can be prepared where Ru is replaced by Mo, Fe, Co, Cr, Ni and/or W. Similarly Se can be replaced by S.

Abstract: A fuel cell based system for the generation of electrical energy employs a drive unit that includes at least two electric motors sharing a common rotor which is mechanically coupled to drive a compressor to provide oxidant and/or fuel to a fuel cell. An electrical storage device such as a battery produces a voltage in at least a low voltage one of the electric motors to startup the system, and the fuel cell supplies a voltage to a high voltage one of the electric motors to drive the compressor, one or more loads such as a traction motor, and/or recharge the electrical storage device during standard operation.

Abstract: A method for coating an ion-exchange membrane with a catalyst layer by first heating a surface of the membrane to thereby soften the surface, followed by deposition of a catalyst composition and compaction into the ion-exchange membrane to produce a catalyst-coated membrane. Heating of the ion-exchange membrane may be at a temperature between 20° C. and 50° C., typically between 30° C. and 40° C., above the glass transition temperature of the dry ion-exchange membrane. In one embodiment, the catalyst composition is fluidized in a fluidized bed reactor prior to being deposited on the membrane surface. A system for coating the ion-exchange membrane is also provided. The catalyst-coated membrane is particularly useful in electrochemical fuel cells.

Abstract: The present invention is generally directed to systems and methods for distributing a non-odorized gas. In one embodiment, an inner pipe containing a non-odorized gas at a first pressure is routed through an outer pipe adapted to contain an odorized fluid at a second pressure less than the first pressure. As a result of the pressure differential, a leak in the inner pipe will not permit the odorized fluid in the outer pipe to flow into the inner pipe. When the non-odorized gas is hydrogen, this prevents a stream of hydrogen gas that is possibly contaminated with odorants from reaching a fuel cell. Furthermore, a leak in the outer pipe or a leak in both the inner and outer pipes will result in the release of the odorized fluid into the environment, allowing leaks to be detected before dangerous or harmful levels are reached.

Abstract: An electrical contacting device for a fuel cell assembly comprises a printed circuit board comprising electrically conductive regions for providing reliable electrical contact with fuel cell components of the fuel cell assembly. Preferably the printed circuit board is flexible. The contacting device may be used, for example, for monitoring cell operating parameters like current or voltage, for short circuiting or by-passing individual cells or for directing signals to the stack.