Abstract: A fuel cell power plant assembly includes an accumulator having a housing. In one example, at least one demineralizer portion is positioned to interact with fluid within the accumulator housing. This allows for warm fluid within the accumulator housing to provide heat to the demineralizer portion. In one example, the demineralizer portion is within the housing. Another example includes a separator supported within the housing of the accumulator. A disclosed example includes a conical shaped baffle as the separator. The separator separates liquid from gas and facilitates distributing fluid flow within the accumulator housing to provide increased heat exchange with the demineralizer portion within the housing.

Abstract: A catalyst support for an electrochemical system includes a high surface area refractory material core structure and boron-doped diamond. The BDD modifies the high surface area refractory material core structure.

Abstract: A fuel cell stack includes at least one fuel cell having a fuel inlet for directing a hydrogen fuel to the fuel cell to generate electric current; a sensor cell having an anode, a cathode and a membrane between the anode and the cathode, the anode being communicated with the fuel inlet to receive a portion of fuel from the fuel inlet, the sensor cell being connected across the stack to carry the electric current whereby hydrogen from the portion of fuel is electrochemically pumped to the cathode of the sensor cell; and a sensor communicated with the sensor cell to receive a signal corresponding to evolution of hydrogen from the anode to the cathode of the sensor cell and adapted to detect contaminants in the fuel based upon the signal.

Abstract: In a fuel cell stack, an inlet fuel distributor (15, 31, 31a, 31b) comprises a plurality of fuel distributing passageways (17-23, 40-47, 64) of substantially equal length and equal flow cross section to uniformly distribute fuel cell inlet fuel from a fuel supply conduit (13, 14, 50) to a fuel inlet manifold (28). The conduits may be either channels (40-47; 64) formed within a plate (39) or tubes (17-23). The channels may have single exits (65) or double exits (52, 53) into the fuel inlet manifold.

Abstract: A fuel cell power plant (100) having a stack of fuel cells (102), each having an anode (104), a fuel reactant gas flow field plate (118), a cathode (106), an oxidant reactant gas flow field plate (120), and an electrolyte (101) between the anode and cathode. The stack has coolant channels (131), an air blower (144), air inlet (139a) and outlet (141a) valves, and a cathode recycle loop using either the primary air blower or a cathode recycle blower (135). A shutdown process includes recycling air through the cathodes with only one of an air inlet valve or air exit valve closed, while applying fresh fuel and recycling fuel through the anodes until oxygen is about 4% or less, or average cell voltage is about 0.2 or less, or for predetermined period of time.

Abstract: A system and method for operating fuel cell power plant 10 includes enclosing fuel bearing components, such as fuel cell stack 28 and reformer 24, into a fuel compartment 12 separate from motorized components in a motor compartment 14, and consuming leaked fuel in the fuel compartment 12 using a fuel bearing component such as cell stack 28 and/or burner 26, thereby reducing fuel emissions from the plant.

Abstract: Fuel cell systems (10) and related methods for limiting fuel cell slippage are provided. A stacked plurality of adjacent fuel cells (14) collectively forming a fuel cell stack (12). The fuel cells each include a pair of first and second plates (30, 30?, 30?; 32, 32?, 32?) at respective opposite ends thereof. A first fuel cell has a first plate (30, 30?, 30?) in engagement with a second plate (32, 32?, 32?) of a second fuel cell adjacent to the first fuel cell. A slip mitigation arrangement (50, 50?, 50?) between at least one of the pairs of the first and second fuel cells comprises first and second seats (62, 62?, 62?; 64, 64?, 64?) recessed in the engagement surfaces of the first and second conductive plates respectively, and a key member (60, 60?, 60?) having opposite ends seated in the first and the second recessed seats such that relative movement between the first and the second fuel cells is limited.

Abstract: A fuel cell (10) includes a cathode catalyst (26) for receiving a first reactant and an anode catalyst (24) for receiving an expected amount of a second reactant. The cathode catalyst (26) and the anode catalyst (24) respectively catalyze the first reactant and the second reactant to produce an electrochemical reaction that generates a flow of electrons between the cathode catalyst (26) and the anode catalyst (24) The amount of the first reactant consumed in the electrochemical reaction corresponds to a threshold amount of the second reactant needed to generate a forward flow of the electrons from the anode catalyst (24) to the cathode catalyst (26). A portion (42) of a fuel cell flow field includes a feature (54, 60, 80, W1, D1) that restricts consumption of the first reactant.

Abstract: A reactant flow field (19, 21) has multiple flow field channels (30, 32) and chambers (34). The multiple flow field channels (30, 32) and chambers (34) require reactant entering the flow field (19, 21) to traverse a flow transition (38) multiple times before exiting the flow field (19, 21).

Abstract: A PEM fuel cell power plant includes fuel cells, each of which has a cathode reactant flow field plate which is substantially impermeable to fluids, a coolant source, and a fluid permeable anode reactant flow field plate adjacent to said coolant source. The anode reactant flow field plates pass coolant from the coolant sources into the cells where the coolant is evaporated to cool the cells. The cathode flow field plates prevent reactant crossover between adjacent cells. By providing a single permeable plate for each cell in the power plant the amount of coolant present in the power plant at shut down is limited to a degree which does not require adjunct coolant purging components to remove coolant from the plates when the power plant is shut down during freezing ambient conditions. Thus the amount of residual frozen coolant in the power plant that forms in the plates during shut down in such freezing conditions will be limited.

Abstract: A system and method for recovering and separating water vapor and electrolyte vapor from an exhaust stream (22) of a fuel cell uses a membrane tube (72) comprising membrane (74) having an outer wall (76) and an inner wall (78), wherein exhaust stream (22) is directed to contact outer wall (76), electrolyte vapor is condensed on outer wall (76), and water vapor is condensed inside the membrane (74), the condensed water drawn from the membrane (74) to inner wall (78), leaving behind condensed electrolyte (88) on outer wall (76).

Abstract: A membrane electrode assembly includes an anode including a hydrogen oxidation catalyst; a cathode; a membrane disposed between the anode and the cathode; and a peroxide decomposition catalyst positioned in at least one position selected from the group consisting of a layer between the anode and the membrane and a layer between the cathode and the membrane wherein the peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from the hydrogen peroxide. The peroxide decomposition catalyst can also be positioned within the membrane. Also disclosed is a power-generating fuel cell system including such a membrane electrode assembly, and a process for operating such a fuel cell system. The assembly components contain ionomer material which can be perfluorinated or non-perfluorinated, high temperature, hydrocarbon, and the like.

Abstract: During a process of shutting down a fuel cell power plant (11) the exits (28) of the anodes (14) are vented (76-77) under liquid (57). The liquid may be that of a coolant accumulator (57) of a fuel cell stack (12) cooled by conduction and convection of sensible heat into liquid coolant (FIG. 1) or evaporatively cooled (FIG. 4). The vent (77) may be under liquid all of the time (FIGS. 1, 3 and 4) or only after the stack has been drained of coolant (FIG. 2). The vent (77) may be the only vent for the anode exits (FIG. 3), or there may also be a purge vent valve (31) (FIGS. 1 and 4).

Abstract: A system and method for passivating a fuel cell power plant 10 with hydrogen fuel utilizes a fuel blower 10 to assist in circulating fuel between a fuel processing system 38 and air processing system 12 via an inlet transfer line 66 connecting fuel feed line 42 and air feed line 18, as well as an outlet transfer line 60 connecting a fuel outlet line 56 to an air outlet line 36, and does not require the use of a combustible gas fuel certified air blower.

Abstract: The present invention provides a fuel cell which is capable of improving electric power generation efficiency at a time of high-temperature operation. The fuel cell 10 comprising: a membrane electrode assembly 4; and a pair of gas separators 7, 8 sandwiching the membrane electrode assembly 4 therebetween, wherein at least one of the gas separator(s) 7 and/or 8 comprises a compact layer(s) 7c and/or 8c which is capable of preventing permeation of fluid and a porous layer (s) 7d and/or 8d which allows permeation of fluid, and the porous layer(s) 7d and/or 8d is impregnated with a water-soluble liquid having higher boiling point than that of water.

Abstract: A fluid detection system and method is disclosed having sensor elements 66 comprising wire leads 68 and electrodes 74 electrically insulated from the stack 16, and positioned such that a measurable voltage is present between the sensor elements 66 only when fluid in water exit manifold space 54 is in contact with both of the electrodes 74. Sensor element 76 may also be utilized in combination with one or both sensor elements 66, and comprises a wire lead 68 operably connected to a pressure plate 60. Because pressure plate 60 is electrically conductive and in electrical communication with stack 16, a voltage measurable between sensor element 76 and sensor element 66 can be used to indicate that fluid is in contact with electrode 74 of sensor element 66. The placement of the electrodes 78, 80 can further indicate a level of fluid or flow of fluid through stack 16.

Abstract: The electrical output connections (155, 158) of a fuel cell stack (151) are short circuited (200; 211, 212) during start up from freezing temperatures. Before the stack is short circuited, fuel is provided in excess of stoichiometric amount for a limiting stack current, and oxidant is provided to assure stoichiometric amount for the limiting stack current.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) cross sections having intersecting polygons or other shapes, obtuse angles including triangles and trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120), or (e) diverging channels (152).

Abstract: A stabilized platinum nanoparticle has a core portion surrounded by a plurality of outer surfaces. The outer surfaces include terrace regions formed of platinum atoms, and edge and corner regions formed of atoms from a second metal. The stabilized nanoparticle may be formed by combining a platinum nanoparticle with a metal salt in a solution. Ions of the second metal react with platinum and replace platinum atoms on the nanoparticle. Platinum atoms from the edge and corner regions react with the second metal ions quicker than surface atoms from the terraces, due to a greater difference in electrode potential between the platinum atoms at the edge and corner regions, as compared to the second metal in the solution. The platinum nanoparticle may include surface defects, such as steps and kinks, which may also be replaced with atoms of the second metal. In an exemplary embodiment, the platinum nanoparticle is a cathode catalyst in an electro-chemical cell.

Abstract: During fuel cell startup and shutdown or other power reduction transitions of a fuel cell power plant, the excess electric energy generated by consumption of reactants is extracted by a storage control (200) in response to a controller (185) as current applied to an energy storage system 201 (a battery). In a boost embodiment, an inductor (205) and a diode (209) connect one terminal (156) of the stack (151) of the battery. An electronic switch connects the juncture of the inductor and the diode to both the other terminal (155) of the stack and the battery. The switch is alternately gated on and off by a signal (212) from a controller (185) until sufficient energy is transferred from the stack to the battery. In a buck environment, the switch and the inductor (205) connect one terminal (156) of the stack to the battery. A diode connects the juncture of the switch with the inductor to the other terminal (155) of the fuel cell stack and the battery.