Abstract: A decrease in voltage in a polymer electrolyte fuel cell comprising stack of unit cells caused by the temperature difference between the cells located at the ends and the other cells due to a differential in heat dissipation from end plates is prevented by controlling the cooling temperature of the cells closest to the end plates of the fuel cell without affecting the output voltage of the cells in the middle by not including a coolant flow channel in the conductive separator plate between at least one of the end plates and the unit cell located closest to the one of the end plates.

Abstract: A polymer electrolyte fuel cell of the present invention includes conductive separator plates comprising molded plates of a composition comprising a binder, conductive carbon particles whose average particle diameter is not less than 50 ?m and not more than ? of the thickness of the thinnest portion of the conductive separator plate, and at least one of conductive carbon fine particles and micro-diameter carbon fibers. The separator plates do not require conventional cutting processes for gas flow channels, etc., and can be easily mass produced by injection molding and achieve a reduction in the cost.

Abstract: A decrease in voltage in a polymer electrolyte fuel cell comprising stack of unit cells caused by the temperature difference between the cells located at the ends and the other cells due to a differential in heat dissipation from end plates is prevented by controlling the cooling temperature of the cells closest to the end plates of the fuel cell without affecting the output voltage of the cells in the middle by not including a coolant flow channel in the conductive separator plate between at least one of the end plates and the unit cell located closest to the one of the end plates.

Abstract: A polymer electrolyte fuel cell of the present invention includes a hydrogen ion-conductive polymer electrolyte membrane, an anode and a cathode sandwiching the hydrogen ion-conductive polymer electrolyte membrane, an anode-side conductive separator plate having a gas flow channel for supplying a fuel gas to the anode, and a cathode-side conductive separator plate having a gas flow channel for supplying an oxidant gas to the cathode.

Abstract: A polymer electrolyte fuel cell comprising: a plurality of conductive separator plates, each comprising a corrugated metal plate; an electrolyte membrane-electrode assembly inserted between the separator plates, the electrolyte membrane-electrode assembly including a hydrogen-ion conductive polymer electrolyte membrane having its periphery covered with a gasket, an anode attached to one side of the electrolyte membrane, and a cathode attached to the other side of the electrolyte membrane; and gas charge and discharge device for charging and discharging a fuel gas and an oxidant gas to and from the anode and the cathode, respectively, wherein the gas charge and discharge device charges and discharges the fuel gas to and from the anode through the grooves on one side of the corrugated metal plate and charges and discharges the oxidant gas to and from the cathode through the grooves on the other side of the corrugated metal plate.

Abstract: A fuel cell including a cell stack including plural electrically conductive separator plates and MEAs (electrolyte membrane-electrode assemblies) inserted among the separator plates. The fuel cell further includes gas communication grooves, where the gas communication grooves on one main surface of each separator plate are positioned to correspond to the ribs on the other main surface thereof, whereby thin wall portions in the separator plate can be avoided as much as possible, thereby to solve above described problems.