Abstract: A fuel cell has an anode, a cathode, and a proton-exchange membrane disposed between the anode and cathode. An exhaust anode gas exhausted from an outlet of the anode is directed back to an inlet of the anode. Hydrogen is added to the exhaust anode gas before the exhaust anode gas reaches the inlet.

Abstract: A fuel cell has an anode, a cathode, and a proton-exchange membrane disposed between the anode and cathode. An exhaust anode gas exhausted from an outlet of the anode is directed back to an inlet of the anode. Hydrogen is added to the exhaust anode gas before the exhaust anode gas reaches the inlet.

Abstract: A fuel cell stack comprises membrane electrode assemblies (3) in which gas diffusion electrodes (2a,2b) are arranged on both sides of an ion exchange membrane (1) and a reactant gas supply separators (5) interposed between the membrane electrode assemblies (3). The reactant gas supply separators (5) each has a first surface having first reactant gas supply grooves (9a) for supplying first reactant gas, a second surface having second reactant gas supply grooves (9b) for supplying an second reactant gas, and water supply means for supplying water to the first reactant gas supply grooves (9a). The water supply means has a water supply grooves (15) for introducing water from a water supply manifold (14) disposed on the second surface, communication holes (16) for communication of the second surface with the first surface, and a buffer section (17) having a porous body (20) for uniformly distributing water from the water supply grooves (15) to the communication holes (16).

Abstract: In a polymer electrolyte fuel cell stack using a latent heat cooling system, a plurality of first reactant gas flow paths formed in one plate surface of each separator are made substantially linear in the vertical direction, and an arrangement capable of supplying water to the first reactant gas flow paths includes a water manifold formed to extend through the separator, a water supply path branched from the water manifold and horizontally formed in a surface in which second reactant gas flow paths are formed, and communication holes horizontally formed in a first reactant gas flow path introducing portion to allow the water supply path to communicate with the first reactant gas flow paths, and present above the lowermost portion in the vertical direction of the water manifold. With this arrangement, stable power generation can be performed regardless of, e.g., the stack installation angle or vibrations.

Abstract: A solid polymer fuel cell having a structure in which a film electrode composite having gas diffusion electrodes disposed on both surfaces of a solid polymer film and separators having gas channels to feed at least either a fuel gas or an oxidant gas to the electrodes are laminated repeatedly in such a manner that they contact each other, wherein the separators each comprise a carbon resin composite material and an expansion graphite layer, on at least one surface of the material, pits and projections to form the gas channels are formed, and the layer is formed on the surfaces of the material including the pits and the projections.

Abstract: In a polymer electrolyte fuel cell stack using a latent heat cooling system, a plurality of first reactant gas flow paths formed in one plate surface of each separator are made substantially linear in the vertical direction, and an arrangement capable of supplying water to the first reactant gas flow paths includes a water manifold formed to extend through the separator, a water supply path branched from the water manifold and horizontally formed in a surface in which second reactant gas flow paths are formed, and communication holes horizontally formed in a first reactant gas flow path introducing portion to allow the water supply path to communicate with the first reactant gas flow paths, and present above the lowermost portion in the vertical direction of the water manifold. With this arrangement, stable power generation can be performed regardless of, e.g., the stack installation angle or vibrations.

Abstract: To render a polymer electrolyte fuel cell and a power-generating system with polymer electrolyte fuel cells, simple, compact and lightweight, the following measures are taken. A plurality of reactant-gas supplying separator are provided, each on at least one surface of each unit cell. Each reactant-gas supplying separator has fuel-gas supplying passages such as grooves in one surface, and oxidizer-gas supplying passages such as grooves in the other surface. Each unit cell comprises a catalyst layer and an electrically conductive, porous water-repellant layer provided at least between the catalyst layer and the grooves. The system comprises water-supplying means for supplying water in liquid state to a fuel-gas inlet section and a water-amount control means for controlling the amount of water to be supplied to the fuel-gas inlet section.

Abstract: A solid polymer fuel cell having a structure in which a film electrode composite having gas diffusion electrodes disposed on both surfaces of a solid polymer film and separators having gas channels to feed at least either a fuel gas or an oxidant gas to the electrodes are laminated repeatedly in such a manner that they contact each other, wherein the separators each comprise a carbon resin composite material and an expansion graphite layer, on at least one surface of the material, pits and projections to form the gas channels are formed, and the layer is formed on the surfaces of the material including the pits and the projections.

Abstract: A fuel cell stack comprises membrane electrode assemblies (3) in which gas diffusion electrodes (2a,2b) are arranged on both sides of an ion exchange membrane (1) and a reactant gas supply separators (5) interposed between the membrane electrode assemblies (3). The reactant gas supply separators (5) each has a first surface having first reactant gas supply grooves (9a) for supplying first reactant gas, a second surface having second reactant gas supply grooves (9b) for supplying an second reactant gas, and water supply means for supplying water to the first reactant gas supply grooves (9a). The water supply means has a water supply grooves (15) for introducing water from a water supply manifold (14) disposed on the second surface, communication holes (16) for communication of the second surface with the first surface, and a buffer section (17) having a porous body (20) for uniformly distributing water from the water supply grooves (15) to the communication holes (16).