Abstract: An integrated current collector and electrical component plate for a fuel cell stack is disclosed, comprising a printed circuit board comprising the following layers: a current collection layer, comprising a current collector; a first insulation layer, comprising a first surface and a second surface; an electrical component layer, comprising an electrical component having a first connection site and a second connection site; and a second insulation layer, comprising a first surface and a second surface, wherein the current collection layer is laminated to the first surface of the first insulation layer, and the electrical component layer is laminated between the second surface of the first insulation layer and the first surface of the second insulation layer. A fuel cell stack and methods for manufacturing a fuel cell stack comprising the integrated current collector and electrical component plate are also disclosed.

Abstract: An array of 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, with or without switching. The configuration of fuel cell systems may be automatic and may be based on desired power, current and/or voltage, and/or based on the operating parameters of the fuel cell systems and/or power supply system.

Abstract: Electrochemical fuel cell stacks comprising a plurality of membrane electrode assemblies stacked in an alternating manner, such that the polarity of adjacent membrane electrode assemblies are opposite, are disclosed. The fuel cell stacks comprise a plurality of membrane electrode assemblies, each membrane electrode assembly comprising an anode fluid distribution layer, a cathode fluid distribution layer, a polymer electrolyte membrane interposed between the anode and cathode fluid distribution layers, an anode electrocatalyst layer interposed between the polymer electrolyte membrane and the anode fluid distribution layer, and a cathode electrocatalyst interposed between the polymer electrolyte membrane and the cathode fluid distribution layer, wherein the plurality of membrane electrode assemblies are stacked in an alternating manner such that the polarity of adjacent membrane electrode assemblies are opposite, and wherein the plurality of membrane electrode assemblies are externally jumpered.

Abstract: An electrochemical fuel cell comprises an anode electrocatalyst layer, a cathode electrocatalyst layer, a polymer electrolyte membrane interposed between the anode and cathode electrocatalyst layers, an anode flow field plate, a cathode flow field plate, an anode fluid distribution layer interposed between the anode flow field plate and the anode electrocatalyst layer, and a cathode fluid distribution layer interposed between the cathode flow field plate and the cathode electrocatalyst layer, wherein at least one of the anode and cathode fluid distribution layers decreases in permeability from an inlet to an outlet of the electrochemical fuel cell. Methods for making a substantially fluid impermeable sheet material having a non-uniform pattern of perforations are also provided.

Abstract: A contacting device comprising a non-metallic, electrically conductive elastomeric composition for providing reliable, corrosion resistant electrical contacts to fuel cell components. Such a contacting device is particularly suitable for measuring voltages at carbon separator plates in a solid polymer electrolyte fuel cell stack.

Abstract: An apparatus for recirculating a reactant fluid stream of a fuel cell system, and electric power generation systems comprising the apparatus, are disclosed. The apparatus comprises (1) a common suction chamber fluidly connected to a suction inlet configured to receive a recirculated flow from the exhaust stream of the fuel cell stack, (2) a low-flow nozzle positioned in the common suction chamber and fluidly connected to a low-flow motive inlet configured to receive a first motive flow from a reactant source of the fuel cell stack, (3) a low-flow diffuser fluidly connected to a discharge outlet configured to provide the inlet stream to the fuel cell stack, (4) a high-flow nozzle positioned in the common suction chamber and fluidly connected to a high-flow motive inlet configured to receive the first motive flow from the reactant source, and (5) a high-flow diffuser fluidly connected to the discharge outlet.

Abstract: Liquid cooled systems having coolant circulation loops must often operate in below freezing conditions. For instance, in various applications certain fuel cell systems must be able to tolerate repeated shutdown and storage in below freezing conditions. Conventional glycol-based coolants typically used for internal combustion engines are generally unsuitable for use in the associated fuel cell cooling subsystems due to the presence of additives and/or inhibitors which are normally included to deal with problems relating to decomposition of the glycol. With additives or inhibitors present, the coolant conductivity can be sufficiently high as to result in electrical shorting or corrosion problems. However, provided the purity of the coolant is maintained, a pure glycol and water coolant mixture may be used as a fuel cell system coolant to obtain suitable antifreeze protection. Adequate purity can be maintained by including an ion exchange resin unit in the cooling subsystem.

Abstract: A process for preparing a graft copolymers is provided comprising exposing a polymeric base material to a dose of ionizing radiation, and then contacting the irradiated base material with a microemulsion comprising at least one fluorostyrenic monomer, water and water-miscible solvent. The graft copolymer may be formed into a membrane, including ion exchange membranes.

Abstract: An electrochemical fuel cell stack comprises a plurality of fuel cell assemblies, wherein, each fuel cell assembly comprises a cell compressed between a pair of flow field plates, a perimeter seal circumscribing the cell and interposed between the pair of flow field plates, and a first diode, having an aspect ratio greater than 10:1, positioned adjacent to, and outside of, the perimeter seal along a first edge of the cell and interposed between the pair of flow field plates.

Abstract: A membrane electrode assembly may be made using a one-sided catalyst coated membrane (CCM) wherein only one catalyst layer, either the anode or the cathode, is coated directly on the ion-exchange membrane. In particular, a one-sided CCM may be used where it may not be practicable to coat both sides of the ion-exchange membrane with catalyst layers such as when PTFE is added to the anode catalyst layer to render it reversal tolerant.

Abstract: In a hydrogen gas line where the composition of the gas is primarily hydrogen, impurities present in the gas line will typically reduce the speed of sound. Accordingly, an acoustic sensor can be used in such a hydrogen gas line to indicate when impurities have accumulated in the gas line. In particular, the hydrogen gas line may be in a fuel line for an electrochemical fuel cell system. The sensor may comprise transducers, more particularly piezoelectric transducers, as both sound detectors and/or sound generators. Further, the sensor can measure either the speed or frequency of sound to determine the hydrogen concentration. If the fuel is recirculated back to the anode inlet, such a hydrogen sensor in the anode exhaust may be used to determine when it is beneficial to purge the anode exhaust to the external atmosphere.

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: A fuel cell system is operated with the fuel supply pressure greater than the oxidant supply pressure to the fuel cell. This gives improved performance particularly when the fuel cell system is closed on the fuel side. The magnitude of fuel overpressure may be varied in accordance with variations in the fuel cell operating parameters.

Abstract: A fuel cell system determines each of a battery charging current error, a battery voltage error, and a stack current error. The fuel cell system regulates current through a series pass element in response to a greater of the determined errors. Thus, the fuel cell system operates in three modes: battery voltage limiting mode, stack current limiting mode and battery charging current limiting mode. Additionally, there can be a fourth “saturation” mode where the stack voltage VS drops below the battery voltage VB as the load pulls even more current. Individual fuel cell systems can be combined in series and/or parallel to produce a combined fuel cell system having a desired output voltage and current.

Abstract: A fuel cell system for powering a work load includes a fuel cell stack and a shunt regulator having a threshold detection; transistorized power switching element, and a dump load. The threshold detection element identifies when an abnormally high voltage rises. The power switching element routes power from the high voltage buss to the dump load. The dump load acts as an electrical energy sink, and may provide dissipated energy to the fuel cell stack in the form of heat. The switching element can also shunt power to the dump load when a digital control signal is set, for example at startup or during cold start conditions.

Abstract: Apparatus and methods of ceasing operation of an electric power generating system improve the cold starting capability of the system. The system comprises a fuel cell stack connectable to an external circuit for supplying power to the external circuit. The stack comprises at least one solid polymer fuel cell, and the system further comprises a fuel passage for directing a fuel stream through the stack and an oxidant passage for directing an oxidant stream through the stack, a sensor assembly connected to the stack for monitoring a parameter indicative of stack performance, a controller for controlling at least one stack operating parameter, and a control system communicative with the sensor assembly and stack operating parameter controller.

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: 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: A membrane exchange humidifier employs a water permeable membrane comprising a microporous polymer and a hydrophilic additive. In operation, the membrane preferably has favorable water transmission properties and resists transmission of reactant gas or other components. The membrane is suitable for use even when permeable in its dry condition to the wet or dry gases in the humidifier, and/or when the wet and dry gases are of different composition. By wetting the membrane, the presence of an amount of liquid water in the wet gas can reduce gas transmission through the membrane to an acceptable level. The humidifier is useful in fuel cell systems in which a reactant gas supply stream, such as the oxidant supply stream, is humidified primarily using water vapor from a fuel cell reactant exhaust stream. The humidifier is particularly suitable for use in conjunction with solid polymer fuel cell systems. The improved mechanical and welding properties of the membrane allow for a simpler humidifier configuration.

Abstract: A membrane electrode assembly with an improved integrated seal comprises an edge seal having an inboard pad attached to the edge of the electrodes, a flexible coupling adjacent the pad, and a sealing element adjacent the coupling. The sealing element is significantly thicker than the pad, and the flexible coupling isolates the pad from stress experienced in the sealing element. Thus, greater compression can be applied to the sealing element, thereby providing an improved and more reliable seal, without overly compressing and damaging the attached pad.