Abstract: A fuel cell system includes a fuel cell; a fuel gas supplying unit supplying the fuel gas into the fuel cell on the anode side thereof; an oxidizing agent gas supplying unit supplying the oxidizing agent gas into the fuel cell on the cathode side thereof; a raw material gas supplying unit supplying the raw material gas into the fuel cell; and a controlling unit controlling the supply of the fuel gas, the oxidizing agent gas and the raw material gas. After switching the output of electric power or the fuel cell off, the fuel gas supplying unit suspends the supply of the fuel gas, the oxidizing agent gas supplying unit suspends the supply of the oxidizing agent gas and the raw material gas supplying unit supplies the raw material gas into the fuel cell to purge the fuel cell on the cathode side.

Abstract: Problems of acceleration of drying of electrolyte membrane and local reaction, etc. can be properly coped with to attain the stabilization of performance of fuel cell.

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 catalyst-coated membrane includes: a first catalyst layer (2a) and a second catalyst layer (2b) which are opposed to each other; a polymer electrolyte membrane 1 which is disposed between the first catalyst layer (2a) and the second catalyst layer (2b) and has a first main surface (F10) and a second main surface (F20) which are opposed to each other; and a membrane catalyst concentration reduced region 80 which is formed so as to contact an outer periphery of the first catalyst layer (2a) and the first main surface (F10) of the polymer electrolyte membrane 1 and has hydrogen ion conductivity and fire resistance, wherein: an outer periphery of the main surfaces of the second catalyst layer (2b) is located between an edge of the membrane catalyst concentration reduced region (80) which edge contacts the first catalyst layer (2a) and an edge opposed to the edge contacting the first catalyst layer (2a); and the membrane catalyst concentration reduced region (80) includes a first portion (8) which contacts the f

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 1/1500 to about 1/5, 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.

Abstract: Provided is a fuel cell system including a polymer electrolyte fuel cell with improved durability, which is capable of suppressing a phenomenon in which a polymer electrolyte membrane is decomposed and degraded. In the fuel cell system including the polymer electrolyte fuel cell including: a membrane electrode assembly including a polymer electrolyte membrane with hydrogen ion conductivity, and a fuel electrode and an oxidant electrode sandwiching the polymer electrolyte membrane; a first separator plate for supplying and discharging a fuel gas to and from the fuel electrode; and a second separator plate for supplying and discharging an oxidant gas to and from the fuel electrode, a metal ion supplying means for supplying metal ions, which are stable in an aqueous solution, to the inside of the membrane electrode assembly in an amount equivalent to 1.0 to 40.0% of the ion exchange group capacity of the polymer electrolyte membrane is disposed.

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: Problems of acceleration of drying of electrolyte membrane and local reaction, etc. can be properly coped with to attain the stabilization of performance of 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 fuel cell component includes an electrolyte membrane and insert members disposed within the electrolyte membrane. The insert members are arranged to provide compression resistance of the assembly of the insert members and electrolyte membrane. Creep resistance of the assembly of the insert members and electrolyte membrane is greater than a creep resistance of the electrolyte membrane alone.

Abstract: The deterioration of the catalyst can occur during prolonged storage, occasionally causing the deterioration of the durability of the fuel cell.

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: In order to obtain an electrolyte membrane-electrode assembly using a thin electrolyte membrane, the present invention provides a production method of an electrolyte membrane-electrode assembly comprising: a step of forming a hydrogen ion-conductive polymer electrolyte membrane on a base material; a treatment step of reducing adhesion force between the base material and the hydrogen ion-conductive polymer electrolyte membrane; a step of separating and removing the base material; and a step of bonding a catalyst layer and a gas diffusion layer onto the hydrogen ion-conductive polymer electrolyte membrane, and, in order to obtain an electrolyte membrane-electrode assembly which has a catalyst without clogging and is excellent in electrode characteristics, the present invention provides a production method of an electrolyte membrane-electrode assembly comprising: a step of bonding a hydrogen ion-conductive polymer electrolyte membrane and a catalyst layer via a coating layer; a step of removing the coating layer

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: An electrolyte membrane-electrode assembly for a fuel cell includes a polymer electrolyte membrane and a pair of electrodes sandwiching the electrolyte membrane. Each of the electrodes includes a catalyst layer in contact with the polymer electrolyte membrane and a gas diffusion layer in contact with the catalyst layer, and the polymer electrolyte membrane includes electronically insulating particles, which serve as spacers for separating the gas diffusion layers of the electrodes, in a region sandwiched between the electrodes.

Abstract: A fuel cell component includes an electrolyte membrane and insert members disposed within the electrolyte membrane. The insert members are arranged to provide compression resistance of the assembly of the insert members and electrolyte membrane. Creep resistance of the assembly of the insert members and electrolyte membrane is greater than a creep resistance of the electrolyte membrane alone.

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: 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.

Abstract: In order to obtain an electrolyte membrane-electrode assembly using a thin electrolyte membrane, the present invention provides a production method of an electrolyte membrane-electrode assembly comprising: a step of forming a hydrogen ion-conductive polymer electrolyte membrane on a base material; a treatment step of reducing adhesion force between the base material and the hydrogen ion-conductive polymer electrolyte membrane; a step of separating and removing the base material; and a step of bonding a catalyst layer and a gas diffusion layer onto the hydrogen ion-conductive polymer electrolyte membrane, and, in order to obtain an electrolyte membrane-electrode assembly which has a catalyst without clogging and is excellent in electrode characteristics, the present invention provides a production method of an electrolyte membrane-electrode assembly comprising: a step of bonding a hydrogen ion-conductive polymer electrolyte membrane and a catalyst layer via a coating layer; a step of removing the coating layer