Abstract: The durability of a polymer electrolyte fuel cell is very significantly improved by using a tightening pressure of about 2 to 4 kgf/cm2 of area of electrode; or a tightening pressure of about 4 to 8 kgf/cm2 of contact area between electrode and separator plate; or by selecting a value not exceeding about 1.5 mS/cm2 for the short-circuit conductivity attributed to the DC resistance component in each unit cell; or by selecting a value not exceeding about 3 mA/cm2 for the hydrogen leak current per area of electrode of each MEA. Further, in a method of manufacturing or an inspection method for a polymer electrolyte fuel cell stack, fuel cells having high durability can be efficiently manufactured by removing such MEAs or unit cells using such MEAs or such cell stacks having short-circuit conductivity values and/or hydrogen leak current values exceeding predetermined values, respectively.

Abstract: A method of operating a fuel cell capable of suppressing degradation of a fuel cell caused by starting and stopping of the fuel cell, including carrying out a restoring operation by decreasing a voltage of the cathode following termination of the fuel cell.

Abstract: A polymer electrolyte fuel cell system is disclosed, comprising a fuel cell having a predetermined power generation portion configured to operate at a predetermined temperature to generate an electric power using a fuel gas and an oxidizing gas supplied to said fuel cell, and a humidifier configured to humidify the fuel gas and the oxidizing gas, wherein the humidifier is configured to humidify the fuel gas and the oxidizing gas to allow the fuel gas and the oxidizing gas to have dew points higher than the predetermined temperature, the humidified fuel gas and oxidizing gas having the dew points higher than the operating temperature being supplied to the fuel cell.

Abstract: A polymer electrolyte fuel cell has an MEA-gasket assembly including an MEA having a polymer electrolyte membrane, a pair of catalyst layers, and a pair of gas diffusion electrodes, and a pair of gaskets provided on peripheral portions of surfaces on both sides of the MEA with gaps between the respectively adjacent gaskets and gas diffusion electrodes. A pair of electrically conductive separators is disposed to sandwich the MEA-gasket assembly with groove-shaped cell reaction gas passages on inner surfaces of the separators, each of the cell reaction gas passages running sequentially across a first portion of a respective gasket of the pair of gaskets, a first portion of a respective gap of the gaps, a respective gas diffusion electrode of the pair of gas diffusion electrodes, a second portion of the respective gap, and a second portion of the respective gasket. Each of the gaps is at least partially closed by a closure.

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: In order to effectively supply and demand electric power between an electric power supplier and a node or a group of nodes individually having an electric power generator, the present invention provides an electric power supply and demand management system capable of obtaining the difference between the total of electric power supplied from the electric power supplier to the node or group and the total of electric power consumed by the electric power loads of the node or group and capable of transmitting information for increasing/decreasing the amount of electric power supply so that the difference becomes smaller to the electric power supplier.

Abstract: The present invention provides a gas diffusion layer for a fuel cell which has proper rigidity, is easy to handle and contributes to the improvement of the productivity of fuel cells. A method for producing a gas diffusion layer for a fuel cell including a first step of: impregnating a conductive porous substrate made of a conductive carbon fiber cloth or conductive carbon fiber felt with a first dispersion containing a first fluorocarbon resin having thermoplasticity; and baking the first conductive porous substrate at a first baking temperature of not less than the melting point of the first fluorocarbon resin and less than the decomposition temperature of the first fluorocarbon resin to enhance the rigidity of the conductive porous substrate.

Abstract: A polymer electrolyte fuel cell comprising: a hydrogen ion-conductive polymer electrolyte membrane; an anode and a cathode with the electrolyte membrane interposed therebetween; an anode-side conductive separator having a gas flow channel for supply of a fuel gas to the anode; and a cathode-side conductive separator having a gas flow channel for supply of an oxidant gas to the cathode, wherein each of the anode and the cathode comprises at least a catalyst layer in contact with the electrolyte membrane and a gas diffusion layer in contact with the catalyst layer and the separator, and at least one of the anode and the cathode contains a compound represented by the formula (I): R1—O—{(C2H4O)n—(C3H6O)m}—R2??(I) where R1 and R2 are independent of each other and each represents a hydrogen atom or an alkyl group having not less than 5 and not more than 15 carbon atoms, n and m are integers which satisfy 0?n?5, 0?m?5 and 1?n+m?5, and when neither n nor m is 0, at least one of the ethylene oxide group and at leas

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 hydrogen ion-conductive polymer electrolyte membrane; an anode and a cathode with the electrolyte membrane interposed therebetween; an anode-side conductive separator having a gas flow channel for supply of a fuel gas to the anode; and a cathode-side conductive separator having a gas flow channel for supply of an oxidant gas to the cathode, wherein each of the anode and the cathode comprises at least a catalyst layer in contact with the electrolyte membrane and a gas diffusion layer in contact with the catalyst layer and the separator, and at least one of the anode and the cathode contains a compound represented by the formula (I): R1—O—{(C2H4O)n—(C3H6O)m}—R2 ??(I) where R1 and R2 are independent of each other and each represents a hydrogen atom or an alkyl group having not less than 5 and not more than 15 carbon atoms, n and m are integers which satisfy 0?n?5, 0?m?5 and 1?n+m?5, and when neither n nor m is 0, at least one of the ethylene oxide group and at leas

Abstract: A configuration of an electrolyte membrane for a fuel cell is provided, which can be sealed reliably and easily between the separators. The sealing configuration is between the separators and between a peripheral portion of the electrolyte membrane and the respective separators. The sealing configuration includes a frame having an elastic modulus of greater than about 2,000 MPa and less than about 2,000,000 MPa and an elastic body having an elastic modulus of greater than 0 MPa and less than about 200 MPa. In one embodiment, the separators or portions thereof may themselves constitute the at least one elastic body. In another embodiment, the electrolyte membrane may be held by two frames lying on opposite sides of the electrolyte membrane, with the at least one elastic body arranged between the first and second frames sandwiching the membrane and also between the frames and the respective separators.

Abstract: There is provided a polymer electrolyte fuel cell capable of: sufficiently suppressing the progress of drying of the polymer electrolyte in the catalyst layers and of the polymer electrolyte membrane, and in addition, the occurrence of flooding, even if the moistened conditions of the fuel gas or the oxidant gas fed to the fuel cell change; suppressing the degradation of the anode, cathode and polymer electrolyte membrane; and thus reducing the deterioration of the cell performance readily and reliably.

Abstract: In a polymer electrolyte fuel cell including a hydrogen ion conductive polymer electrolyte membrane; a pair of electrodes composed of catalyst layers sandwiching the hydrogen ion conductive polymer electrolyte membrane between them and gas diffusion layers in contact with the catalyst layers; a conductive separator plate having a gas flow channel for supplying a fuel gas to one of the electrodes; and a conductive separator plate having a gas flow channel for supplying an oxidant gas to the other electrode, in order to bring a hydrogen ion conductive polymer electrolyte and a catalyst metal of the catalyst layers containing the hydrogen ion conductive polymer electrolyte and conductive carbon particles carrying the catalyst metal sufficiently and uniformly into contact with each other, the polymer electrolyte is provided in pores of an agglomerate structure of the conductive carbon particles. Consequently, the reaction area inside the electrodes is increased, and higher performance is exhibited.

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: An operation method is provided for a polymer electrolyte fuel cell in an optimum operating condition by regulating the cell by a function represented by a gas flow rate and the difference between a saturated steam pressure and an actual steam pressure, by regulating an in-plane temperature distribution obtained by a cooling water flow direction and by the regulation of a cooling water inlet temperature and a cooling water flow amount; a gas supply amount; a supplied moisture amount; and a current density.

Abstract: The durability of a polymer electrolyte fuel cell is very significantly improved by using a tightening pressure of about 2 to 4 kgf/cm2 of area of electrode; or a tightening pressure of about 4 to 8 kgf/cm2 of contact area between electrode and separator plate; or by selecting a value not exceeding about 1.5 mS/cm2 for the short-circuit conductivity attributed to the DC resistance component in each unit cell; or by selecting a value not exceeding about 3 mA/cm2 for the hydrogen leak current per area of electrode of each MEA. Further, in a method of manufacturing or an inspection method for a polymer electrolyte fuel cell stack, fuel cells having high durability can be efficiently manufactured by removing such MEAs or unit cells using such MEAs or such cell stacks having short-circuit conductivity values and/or hydrogen leak current values exceeding predetermined values, respectively.

Abstract: A polymer electrolyte fuel cell is provided comprising: a hydrogen ion conductive polymer electrolyte membrane; an anode and a cathode sandwiching the hydrogen ion conductive polymer electrolyte membrane; an anode side electroconductive separator having a gas channel for supplying a fuel gas to the anode; a cathode side electroconductive separator having a gas channel for supplying an oxidant gas to the cathode; characterized in that the anode and the cathode comprise a gas diffusion layer and a catalyst layer formed on the gas diffusion layer at the side in contact with the hydrogen ion conductive polymer electrolyte membrane, the catalyst layer has catalyst particles and a hydrogen ion conductive polymer electrolyte, and at least either of hydrogen ion conductivity and gas permeability of at least either of the anode and the cathode varies in a thickness direction of the anode or the cathode.

Abstract: The invention relates to a polymer electrolyte fuel cell comprising a polymer electrolyte film of hydrogen ion conduction; an anode and a cathode between which the electrolyte film is placed; a conductive separator having a channel through which fuel gas is supplied to the anode, and a conductive separator having a channel through which oxidative gas is supplied to the cathode. The conventional conductive separator uses a carbon material that is unlikely to be less costly, and an attempt has been made to use a metal plate in place of the carbon material. Since the metal plate is exposed to an oxidizing atmosphere at high temperature for a long time, however, corrosion may occur, disadvantageously causing the efficiency of power generation to decrease gradually. The polymer electrolyte fuel cell of this invention uses an acid-resistant conductive airtight elastomer as a conductive separator for substantial cost reduction.

Abstract: A separator for a polymer electrolyte fuel cell, which contains electrically conductive carbon and a binder that binds the electrically conductive carbon, comprises a reaction gas passage formed on at least a main surface thereof, wherein a water droplet falling angle of a surface the reaction gas passage is not less than 5 degrees and not more than 45 degrees when a water droplet of not less than 50 ?L and not more than 80 ?L is dropped under a condition in which ambient temperature is not lower than 50° C. and not higher than 90° C. and relative humidity is not less than 70% and not more than 100%.

Abstract: A polymer electrolyte fuel cell is provided comprising: a hydrogen ion conductive polymer electrolyte membrane; an anode and a cathode sandwiching the hydrogen ion conductive polymer electrolyte membrane; an anode side electroconductive separator having a gas channel for supplying a fuel gas to the anode; a cathode side electroconductive separator having a gas channel for supplying an oxidant gas to the cathode; characterized in that the anode and the cathode comprise a gas diffusion layer and a catalyst layer formed on the gas diffusion layer at the side in contact with the hydrogen ion conductive polymer electrolyte membrane, the catalyst layer has catalyst particles and a hydrogen ion conductive polymer electrolyte, and at least either of hydrogen ion conductivity and gas permeability of at least either of the anode and the cathode varies in a thickness direction of the anode or the cathode.