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: The present invention provides a polymer electrolyte fuel cell having an increased reaction area by forming a gas channel, a proton channel and an electron channel very close to each other inside a catalyst layer. This polymer electrolyte fuel cell includes a hydrogen ion conductive polymer electrolyte membrane; and a pair of electrodes having catalyst layers sandwiching the hydrogen ion conductive polymer electrolyte membrane between them and gas diffusion layers in contact with the catalyst layers, in which the catalyst layer of at least one of the electrodes comprises carbon particles supporting a noble metal catalyst, and the carbon particles include at least two kinds of carbon particles adsorbing a hydrogen ion conductive polymer electrolyte in mutually different dispersed states.

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 polymer electrolyte fuel cell of the present invention is equipped with a cell having an MEA having a hydrogen ion-conducting polymer electrolyte membrane and an anode and a cathode sandwiching the polymer electrolyte membrane; a platelike anode-side separator positioned on one side of the MEA so that the front surface thereof contacts the anode, with fuel gas passages through which fuel gas flows being formed in the front surface; and a platelike cathode-side separator positioned on the other side of the MEA so that the front surface thereof contacts the cathode, with oxidizing gas passages through which oxidizing gas flows being formed in the front surface; a cell stack in which a plurality of said cells is stacked; and a cooling water flow passage, through which cooling water flows, formed on at least the rear surface of one from among the anode-side separator and the cathode-side separator of at least a prescribed cell in said cell stack; where said fuel gas, oxidizing gas, and cooling water flow thro

Abstract: It has been difficult to keep the voltage of a polymer electrolyte fuel cell stable for a long period of time because uniform water content control over the plane of the membrane-electrode assembly is impossible. A gas diffusion electrode is produced by forming a conductive polymer layer composed of conductive particles and a polymer material on a porous material composed of carbon fiber, and forming a catalyst layer composed of platinum-carried carbon particles on the plane of the conductive polymer layer. The conductive polymer layer is composed of conductive particles different in particle size, and the content of the conductive particles having the smaller particle size is decreased from one end towards the other end of the gas diffusion electrode.

Abstract: A method of preserving a PEFC stack of the present invention is a method of preserving a PEFC stack that is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The method comprises preserving the polymer electrolyte fuel cell stack in an uninstalled state under a condition in which an oxygen concentration within the oxidizing agent passage and within the reducing agent passage is lower than an oxygen concentration in atmospheric air.

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.

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: There are provided measuring units of measuring the amount of fluoride ions in the waste material from a fuel cell which receives a fuel gas and an oxidizing agent gas containing oxygen to undergo electrochemical reaction by which electricity is generated and a life predicting unit of predicting the life of the fuel cell by the use of the amount of fluoride ions thus measured.

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: A polymer electrolyte fuel cell stack that includes a cell laminate having a plurality of unit cells, which are laid one upon another and each of which includes a polymer electrolyte membrane, a pair of electrodes arranged across the polymer electrolyte membrane and having respective catalytic reaction layers, a separator having means for feeding a supply of fuel gas containing hydrogen gas to one of the electrodes, another separator having means for feeding a supply of oxidant gas to the other of the electrodes, and a manifold for feeding the supply of fuel gas or the supply of oxidant gas to the respective electrode and disposed on a side face of each unit cell. In the polymer electrolyte fuel cell stack, a sealing portion is disposed at least in the vicinity of each electrode. The polymer electrolyte fuel cell stack has excellent durability and productivity.

Abstract: The polymer electrolyte fuel cell of the present invention is equipped with a cell having an MEA having a hydrogen ion-conducting polymer electrolyte membrane and an anode and a cathode sandwiching the polymer electrolyte membrane; a platelike anode-side separator positioned on one side of the MEA so that the front surface thereof contacts the anode, with fuel gas passages through which fuel gas flows being formed in the front surface; and a platelike cathode-side separator positioned on the other side of the MEA so that the front surface thereof contacts the cathode, with oxidizing gas passages through which oxidizing gas flows being formed in the front surface; a cell stack in which a plurality of said cells is stacked; and a cooling water flow passage, through which cooling water flows, formed on at least the rear surface of one from among the anode-side separator and the cathode-side separator of at least a prescribed cell in said cell stack; where said fuel gas, oxidizing gas, and cooling water flow thro

Abstract: A polymer electrolyte fuel cell stack that includes a cell laminate having a plurality of unit cells, which are laid one upon another and each of which includes a polymer electrolyte membrane, a pair of electrodes arranged across the polymer electrolyte membrane and having respective catalytic reaction layers, a separator having means for feeding a supply of fuel gas containing hydrogen gas to one of the electrodes, another separator having means for feeding a supply of oxidant gas to the other of the electrodes, and a manifold for feeding the supply of fuel gas or the supply of oxidant gas to the respective electrode and disposed on a side face of each unit cell. In the polymer electrolyte fuel cell stack, a sealing portion is disposed at least in the vicinity of each electrode. The polymer electrolyte fuel cell stack has excellent durability and productivity.

Abstract: A fuel cell configuration is provided in which a bad single cell found in a stack of cells can be simply removed without destroying the material of the stack. For this purpose, a groove is provided in at least one longitudinal side of the stack between the separators of adjoining fuel cell units. By use of this groove to separate the adjoining fuel cell units, the one bad single cell alone can be easily replaced. The groove may be formed by a simple processing of the edge shapes of one or more the separators.

Abstract: The present specification discloses a polymer electrolyte fuel cell characterized in that each of the cathode and the anode comprises catalyst particles, a hydrogen ion-conductive polymer electrode, a conductive porous base material and a water repellent agent, and water repellency of at least one of the cathode and the anode varies in a direction of thickness or in a plane direction. As such, by varying the degree of the water repellency of the cathode and the anode on the basis of a position, an excellent polymer electrolyte fuel cell having a high discharge characteristic or more specifically a high current-voltage characteristic in a high current density range.

Abstract: A method for producing a polymer electrolyte membrane type fuel cell including a polymer electrolyte membrane, fuel and air electrodes that sandwich therebetween the polymer electrolyte membrane and that each include a gas diffusion layer and a catalyst layer provided in contact with the polymer electrolyte membrane, and separators provided in contact with the gas diffusion layers. A paste containing at least a carbon powder having a catalyst supported thereon is spread over a predetermined support, and the coated support is dried to form the catalyst layer. A cracking occupation area on the electrodes is controlled to a predetermined tolerance by controlling at least one of (1) a thickness of the catalyst layer, (2) a kind of carbon having the catalyst supported thereon, and (3) a drying rate of a solvent of the paste.

Abstract: A highly reliable polymer electrolyte fuel cell includes an anode-side separator plate and a cathode-side separator plate that are provided with an anode-side sealing member and a cathode-side sealing member, respectively. The anode-side and cathode-side sealing members seal the cell in cooperation with a polymer electrolyte membrane at sealing parts where the anode-side and cathode-side sealing members are opposed to each other, thereby preventing gas from leaking out of gas flow channels. One of the anode-side and cathode-side sealing members has a pointed rib that comes in contact with the sealing parts in a linear manner, and the other sealing member comes in contact with the sealing parts surface to surface.

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: A carbon fiber woven fabric for use as a gas diffusion layer base material in a polymer electrolyte fuel cell has a surface that is smoothed and further optimized to inhibit non-uniform infiltration of a coating for water-repellent-layer formation, to provide an electrolyte membrane-electrode assembly suitable for operation under a high humidification condition. The gas diffusion layer base material may be a carbon fiber woven fabric, wherein a ratio of the area of gap portions where neither warp thread nor weft thread exists: (10/W−Y)(10/Z−X) to the area of portions where warp thread is crossing weft thread: XY mm2 is in the range of about {fraction (1/1500)} to about ⅕, where the carbon fiber woven fabric has a warp density of Z threads/cm, a weft density of W threads/cm, a warp thickness of X mm and a weft thickness of Y mm.