Abstract: It was difficult to specify a portion which is a cause of a power generation abnormality of a fuel cell which performs the power generation by feeding an oxygen-containing oxidizer gas into a cathode and feeding a hydrogen-containing fuel gas into an anode. A failure diagnosis method of a fuel cell system, which includes a step for computing an impedance in a prescribed portion of a fuel cell of a fuel cell system from a signal obtained by superposing an alternating current on a direct current as generated from the fuel cell system under a certain operation condition, wherein when in comparison of the impedance with an impedance as computed under a previously determined standard operation condition, an abnormality is present in the prescribed portion of the fuel cell, whether a cause of the abnormality of the prescribed portion resides in any one or plural prescribed sites constituting the fuel cell system is determined by using the comparison result.

Abstract: The present invention is intended to enable efficient assembly of a fuel cell stack without causing any damage to the conductive separator. In a fuel cell including an anode, a cathode, an electrolyte membrane interposed between the anode and the cathode, and conductive separators each having manifold apertures 12 and a flow channel 16 for supplying a gas to the anode or the cathode, manifold aperture connecting portions 15 are formed at an inlet-side end and an outlet-side end of the flow channel 16, respectively. Each of the manifold aperture connecting portions 15 is recessed below the upper surface of the conductive separator 11. Cover plates are fitted and fixed to the recessed portions, respectively.

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: By using a gas diffusion layer for a fuel cell comprising a fabric comprising a warp thread and a weft thread which are made of carbon fiber, wherein the distance X between adjacent intersections where the warp and weft threads cross each other and the thickness Y of the fabric satisfy the equation: 1.4?X/Y?3.5, the present invention reduces the surface asperities of the substrate and prevents a micro short-circuit resulting from the piercing of the polymer electrolyte membrane of the fuel cell by the carbon fibers of the fabric so as to improve the characteristics of the fuel cell.

Abstract: Disclosed is a fuel cell comprising: a hydrogen-ion conductive polymer electrolyte membrane; a pair of electrodes sandwiching the hydrogen-ion conductive polymer electrolyte membrane; a first separator plate having a gas flow path for supplying a fuel gas to one of the electrodes; and a second separator plate having a gas flow path for supplying an oxidant gas to the other of the electrodes, wherein each of the electrodes has an electrode catalyst layer comprising at least a conductive carbon particle carrying an electrode catalyst particle and a hydrogen-ion conductive polymer electrolyte, the electrode catalyst layer being in contact with the hydrogen-ion conductive polymer electrolyte membrane, and at least one of the electrodes comprises a catalyst for trapping the fuel gas or the oxidant gas which has passed through the hydrogen-ion conductive polymer electrolyte membrane.

Abstract: A porous supporting carbon body of a gas diffusion layer is provided with a larger number of smaller pores at its catalyst layer side and a smaller number of larger pores at the other side, particularly with an appropriate distribution of finer mesh at its catalyst layer side and coarser mesh at the other side. As a result, a high performance polymer electrolyte fuel cell is obtained in which water generated at the catalyst layer is quickly sucked out to the gas diffusion layer, and is evaporated at the gas diffusion layer to be effectively exhausted to outside the fuel cell, so that excessive water can be prevented from retaining in the gas diffusion electrode, with the polymer electrolyte membrane being maintained at an appropriately wet condition.

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: By using a gas diffusion layer for a fuel cell comprising a fabric comprising a warp thread and a weft thread which are made of carbon fiber, wherein the distance X between adjacent intersections where the warp and weft threads cross each other and the thickness Y of the fabric satisfy the equation: 1.4?X/Y?3.5, the present invention reduces the surface asperities of the substrate and prevents a micro short-circuit resulting from the piercing of the polymer electrolyte membrane of the fuel cell by the carbon fibers of the fabric so as to improve the characteristics of the fuel cell.

Abstract: A fuel cell includes an electrolyte membrane, a pair of anode-side and cathode-side catalyst layers, a pair of an anode gas diffusion layer and a cathode gas diffusion layer, and a pair of an anode-side separator and a cathode-side separator. Also adjusted in the fuel cell is at least one of a fine pore diameter and a content of a water repellent agent in the anode gas diffusion layer and the cathode gas diffusion layer, so as to satisfy the following equation (1): ?0.07?(Ya?Xa)/((Ya?Xa)+(Yc?Xc))?0.15??(1) wherein Xa represents a water feeding amount in the fuel gas thus fed, Ya represents a water discharging amount in the discharged fuel gas, Xc represents a water feeding amount in the oxidizing gas thus fed, and Yc represents a water discharging amount in the discharged oxidizing gas.

Abstract: The present invention provides ink for forming a catalyst layer containing at least a cation conductive polymer electrolyte, catalyst-supporting particles including conductive carbon particles and an electrode catalyst supported thereon, and a dispersion medium, wherein the polymer electrolyte has a mean inertia radius of 150 to 300 nm. A catalyst layer made of the catalyst layer ink improves in gas diffusion property and increases cell voltage, which allows providing a proton conductive polymer electrolyte fuel cell capable of maintaining the high cell voltage for a long time.

Abstract: A method for easily, quickly and accurately detecting a cross leak or a micro short-circuit in a unit cell or group of cells of a fuel cell stack is provided by determining an electric output of the unit cell or group of cells after stoppage of fuel and/or oxidant and preferably during the introduction of a non-fuel and non-oxidant gas to the cell.

Abstract: An electrolyte fuel system, its operation and program and a recording medium associated with the program is disclosed. Embodiments include a fuel cell system having a load electric current changing means for changing an amount of load electric current that runs in one ore more fuel cells which are operated to generate electricity, a measurement means for measuring voltage responses to the change in said load electric current, a calculating means for calculating impedance of said one or more fuel cells based on said voltage responses measured, and a fuel cell control means for controlling condition for operation of said one or more fuel cells by utilizing calculation results retrieved by said calculating means.

Abstract: A method for producing a membrane electrode assembly 1 for solid polymer electrolyte fuel cell, the membrane electrode assembly 1 including a solid polymer electrolyte membrane 2 comprising an ion exchange membrane, a first electrode 3 having a first catalyst layer 31, and a second electrode 4 having a second catalyst layer 41, the first electrode 3 and the second electrode 4 being disposed so as to be opposed to each other via the ion exchange membrane, the method including: applying a coating solution containing a catalyst onto a base film 101 to form a first catalyst layer 31; applying a coating solution containing an ion exchange resin dissolved or dispersed in a liquid onto the first catalyst layer 31 to form an ion exchange membrane; then applying a coating solution containing a catalyst onto the ion exchange membrane to form a second catalyst layer 41; and finally, peeling off the base film 101 from a resulting laminate.

Abstract: An air purifying apparatus for a fuel cell is provided on a flow route of air supplied to the fuel cell. The air purifying apparatus includes a first pollutant-removing means that oxidizes a pollutant in the air and a second pollutant-removing means that adsorbs and removes the pollutant. The first pollutant-removing means includes a catalyst that oxidizes the pollutant by means of oxygen in the air, and the catalyst has an oxidizing activity with respect to at least one selected from the group consisting of organic substances, nitrogen oxides, sulfur oxides, ammonia, hydrogen sulfide, and carbon monoxide. The first pollutant-removing means may include an ozone generator. The second pollutant-removing means adsorbs and removes the pollutant by means of a porous material carrying at least one selected from the group consisting of permanganates, alkali salts, alkaline hydroxides, and alkaline oxides.

Abstract: A polymer electrolyte fuel cell exhibits an excellent performance with an efficient electrode reaction: by providing a layer containing an electroconductive fine particle between the catalytic reaction layer and the gas diffusion layer in the electrodes; by providing a hydrogen ion diffusion layer on at least either surface of the catalyst particle or the carrier, which carries the catalyst particle in the catalytic reaction layer; or by constituting the catalytic reaction layer with at least a catalyst comprising a hydrophilic carbon material with catalyst particles carried thereon and a water repellent carbon material.

Abstract: The invention relates to methods of operating a fuel cell capable of suppressing degradation of a fuel cell caused by starting and stopping of the fuel cell, and to fuel cell systems for carrying out the method.

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: The polymer electrolyte fuel cell of the present invention exhibits an excellent performance with an efficient electrode reaction; by providing a layer comprising an electroconductive fine particle between the catalytic reaction layer and the gas diffusion layer in the electrodes; by providing a hydrogen ion diffusion layer on at least either surface of the catalyst particle or the carrier, which carries the catalyst particle in the catalytic reaction layer; or by constituting the catalytic reaction layer with at least a catalyst comprising a hydrophilic carbon material with catalyst particles carried thereon and a water repellent carbon material.

Abstract: The specification discloses a fuel cell comprising stacked unit cells, each of the unit cells including a pair of electrodes having a catalytic reaction layer and a gas diffusion layer, an electrolyte layer disposed between the pair of electrodes, a separator having a flow path for supplying a fuel gas to one electrode and a separator having a flow path for supplying an oxidant gas to the other electrode, the separators being placed on the outer side of the electrodes and the unit cells being stacked with the separators placed therebetween, wherein at least the catalytic reaction layer, the gas diffusion layer or the flow path has water-repelling properties. Thereby, a fuel cell having a superior cell performance is obtained.

Abstract: To improve the performance of a catalyst layer of a fuel cell electrode, the weight ratio of a hydrogen ion conductive polymer electrolyte and electroconductive carbon particles in the catalyst layer is controlled to satisfy the formula (1): Y=a·logX−b+c, where log represents natural logarithm, X represents the specific surface area of the electroconductive carbon particles (m2/g), Y=(the weight of the hydrogen ion conductive polymer electrolyte)/(the weight of the electroconductive carbon particles), a=0.216, c=±0.300, b=0.421 at an air electrode and b=0.221 at an fuel electrode.