Abstract: Fuel cell reactant flow field plates (22, 32) are formed by extruding long sections (17, 25) of carbonaceous material, either with straight grooves (18, 28) formed by the extrusion die, or by end milling or arbor milling, and then cut to a proper size, including cuts in which the edges of the plates are at an angle with respect to the grooves. Cooler plates are formed of water-permeable material (39) in which hydrophobic material (40) is impregnated so as to define coolant channels (42-44) with inlets and outlets (47, 49). A two-layer cooler plate is formed by stamping voids in one layer (51) that define coolant flow channels (52) with inlets (54) and outlets (56) while a second layer (59) is stamped with voids (61, 62) that define coolant inlet and exit headers; juxtaposition of the layers, with or without bonding, form the cooler plate. A cooler plate (65) is made by corrugating thin metal sheet, providing coolant channels (68) for cathodes and coolant channels (73) for anodes when interposed therebetween.

Abstract: A method of manufacturing a plate for a fuel cell includes the steps of providing flow channels in a fuel cell plate. Multiple fuel cell plates are joined into a cell stack assembly. A blocking plate is affixed to the fuel cell plate and at least partially obstructs the flow channels. The blocking plate is affixed to the fuel cell plate after the plates have been arranged into the cell stack assembly. The resulting fuel cell provides a fuel cell plate having a perimeter with an edge. The fuel cell plate includes flow channels extending to the edge. The blocking plate is affixed to the fuel cell plate at the edge to at least partially block the flow channel. In this manner, an inexpensive fuel cell plate may be used, and the blocking plate can be configured to create terminated flow channels, which may be used to provide an interdigitated flow field.

Abstract: An illustrative example fuel cell component includes an electrode substrate including a plurality of pores. A first portion of the substrate includes a liquid electrolyte absorbing material in at least some of the pores in the first portion. Those pores respectively have a first unoccupied pore volume. Pores in a second portion of the substrate respectively have a second unoccupied pore volume. The first unoccupied pore volume is less than the second unoccupied pore volume.

Abstract: A membrane electrode assembly is provided which includes an anode; a cathode; a membrane between the anode and the cathode; and a protective layer between the membrane and at least one electrode of the anode and the cathode, the protective layer having a layer of ionomer material containing a catalyst, the layer having a porosity of between 0 and 10%, an ionomer content of between 50 and 80% vol., a catalyst content of between 10 and 50% vol., and an electrical connectivity between catalyst particles of between 35 and 75%. A configuration using a precipitation layer to prevent migration of catalyst ions is also provided.

Abstract: An exemplary fuel cell component includes a generally planar body having a total area defined by a length and width of the body. A first portion of the total area is occupied by a first fuel cell features that renders the first portion unusable for at least one fuel cell function. A second portion of the total area is occupied by a second fuel cell feature that renders the second portion unusable for the fuel cell function. A third portion of the total area is considered an active area of the component that is useful for the fuel cell function. An aspect ratio of the length to the width of the generally planar body is dependent on a dimension of the first portion and a dimension of the second portion.

Abstract: The fuel flow channels (20a) of the end fuel cell (9a) at the anode end (34) of a fuel cell stack are significantly deeper than the fuel flow field channels (20) of the remaining fuel cells (9) in the stack, whereby fuel starvation caused by ice in the fuel flow channels is avoided during cold startup. The fuel flow field channels of the end cell (9) at the anode end of the stack is between about 0.15 mm and about 1.5 mm deeper than the fuel flow field channels in the remaining fuel cells of the stack, or between about 35% and about 65% deeper than the fuel flow field channels in the remaining fuel cells of the stack.

Abstract: An example fuel cell assembly includes a plate having channels configured to facilitate movement of a fuel cell fluid near an area of active flow of fuel cell. The channels include portions having a varying depth that extend laterally outside of the area of active flow.

Abstract: The fuel cell device includes an electrode assembly. A gas diffusion layer is on each side of the electrode assembly. A solid, non-porous plate is adjacent each of the gas diffusion layers. A hydrophilic soak up region is near an inlet portion of at least one of the gas diffusion layers. The hydrophilic soak up region is configured to absorb liquid water from the electrode assembly when the fuel cell device is shutdown.

Abstract: Fuel cell systems and related methods involving accumulators with multiple regions of differing water fill rates are provided. At least one accumulator region with a relatively more-rapid fill rate than another accumulator region is drained of water at shutdown under freezing conditions to allow at least that region to be free of water and ice. That region is then available to receive water from and supply water to, a fuel cell nominally upon start-up. The region having the relatively more-rapid fill rate may typically be of relatively lesser volume, and may be positioned either relatively below or relatively above the other region(s).

Abstract: A fuel cell power plant (36) has vertical fuel cells (102) each sharing a half of a hybrid separator plate (100) which includes a solid fuel flow plate (105) having horizontal fuel flow channels (106) on one surface and coolant channels (108) on an upper portion of the opposite surface, bonded to a plain rear side of a porous, hydrophilic oxidant flow field plate (115) having vertical oxidant flow channels (118). Coolant permeates through the upper portion of the porous, hydrophilic oxidant flow field plates and enters the oxidant flow channels, where it evaporates as the water trickles downward through the oxidant flow field channels, thereby cooling the fuel cell.

Abstract: An example method of controlling a fuel cell power plant based on provided power includes selectively varying an electrical resistance of the variable resistive device responsive to at least one of a power provided by the fuel cell power plant, a current provided by the fuel cell power plant, or a voltage decay rate.

Abstract: An exemplary method includes of operating a fuel cell at a first power output level that includes a plurality of operation parameters. Each operation parameter has a value to satisfy a first power demand. A change between the first power demand and a second power demand is determined. At least a first one of the operation parameters is maintained at a value corresponding to the first power output level or at an intermediate value while at least a second one of the operation parameters is changed to a value corresponding to a second power output level to satisfy the second power demand. The first operation parameter is delayed from changing to a value corresponding to the second power output level until a predetermined criterion is met.

Abstract: A membrane electrode assembly is provided which includes an anode; a cathode; a membrane between the anode and the cathode; and a protective layer between the membrane and at least one electrode of the anode and the cathode, the protective layer having a layer of ionomer material containing a catalyst, the layer having a porosity of between 0 and 10%, an ionomer content of between 50 and 80% vol., a catalyst content of between 10 and 50% vol., and an electrical connectivity between catalyst particles of between 35 and 75%. A configuration using a precipitation layer to prevent migration of catalyst ions is also provided.

Abstract: Fuel cell reactant flow field plates (22, 32) are formed by extruding long sections (17, 25) of carbonaceous material, either with straight grooves (18, 28) formed by the extrusion die, or by end milling or arbor milling, and then cut to a proper size, including cuts in which the edges of the plates are at an angle with respect to the grooves. Cooler plates are formed of water-permeable material (39) in which hydrophobic material (40) is impregnated so as to define coolant channels (42-44) with inlets and outlets (47, 49). A two-layer cooler plate is formed by stamping voids in one layer (51) that define coolant flow channels (52) with inlets (54) and outlets (56) while a second layer (59) is stamped with voids (61, 62) that define coolant inlet and exit headers; juxtaposition of the layers, with or without bonding, form the cooler plate. A cooler plate (65) is made by corrugating thin metal sheet, providing coolant channels (68) for cathodes and coolant channels (73) for anodes when interposed therebetween.

Abstract: An exemplary fuel cell component includes a generally planar body having a total area defined by a length and width of the body. A first portion of the total area is occupied by a first fuel cell features that renders the first portion unusable for at least one fuel cell function. A second portion of the total area is occupied by a second fuel cell feature that renders the second portion unusable for the fuel cell function. A third portion of the total area is considered an active area of the component that is useful for the fuel cell function. An aspect ratio of the length to the width of the generally planar body is dependent on a dimension of the first portion and a dimension of the second portion.

Abstract: The oxidant inlets of the reactant gas flow field grooves (41) of a fuel cell (11) which suffers a crossover between the fuel and oxidant flow fields, due to a leak in the seals, the maxtrix or the membrane of the fuel cell, are blocked with a liquid (50) which cures in place, hot glue, two-part epoxy, or fluoroelastomers. This prevents heating as a result of combusting fuel with oxygen near the site, which avoids excessive heating and damaging of successive fuel cells. As a result, a fuel cell power plant (8) can continue to operate with only a minor loss of voltage and power, thereby avoiding the need to tear down the stack by loosening the tie-bolts. Voltage and hydrogen levels may be used to detect the crossover. The particular cell (11) with the leak can be determined by voltage or hydrogen monitoring, or by immersing the stack in a liquid while applying gas to the fuel inlet of the stack.

Abstract: A membrane electrode assembly is provided which includes an anode; a cathode; a membrane between the anode and the cathode; and a protective layer between the membrane and at least one electrode of the anode and the cathode, the protective layer having a layer of ionomer material containing a catalyst, the layer having a porosity of between 0 and 10%, an ionomer content of between 50 and 80% vol., a catalyst content of between 10 and 50% vol., and an electrical connectivity between catalyst particles of between 35 and 75%. A configuration using a precipitation layer to prevent migration of catalyst ions is also provided.

Abstract: Fuel cell systems and related methods involving accumulators with multiple regions of differing water fill rates are provided. At least one accumulator region with a relatively more-rapid fill rate than another accumulator region is drained of water at shutdown under freezing conditions to allow at least that region to be free of water and ice. That region is then available to receive water from and supply water to, a fuel cell nominally upon start-up. The region having the relatively more-rapid fill rate may typically be of relatively lesser volume, and may be positioned either relatively below or relatively above the other region(s).

Abstract: The fuel flow channels (20a) of the end fuel cell (9a) at the anode end (34) of a fuel cell stack are significantly deeper than the fuel flow field channels (20) of the remaining fuel cells (9) in the stack, whereby fuel starvation caused by ice in the fuel flow channels is avoided during cold startup. The fuel flow field channels of the end cell (9) at the anode end of the stack is between about 0.15 mm and about 1.5 mm deeper than the fuel flow field channels in the remaining fuel cells of the stack, or between about 35% and about 65% deeper than the fuel flow field channels in the remaining fuel cells of the stack.

Abstract: An exemplary method includes of operating a fuel cell at a first power output level that includes a plurality of operation parameters. Each operation parameter has a value to satisfy a first power demand. A change between the first power demand and a second power demand is determined. At least a first one of the operation parameters is maintained at a value corresponding to the first power output level or at an intermediate value while at least a second one of the operation parameters is changed to a value corresponding to a second power output level to satisfy the second power demand. The first operation parameter is delayed from changing to a value corresponding to the second power output level until a predetermined criterion is met.