Abstract: The present invention provides a gas diffusion electrode capable of sufficiently preventing not only degradation of MEA during storage but also degradation of initial characteristics and durability during the time period from production to initial use, and a polymer electrolyte fuel cell including the gas diffusion electrode. The gas diffusion electrode includes a catalyst layer in which A1 representing a total mass of organic substance comprising alcohol, a partial oxide of the alcohol, a product of intramolecular dehydrogenation reaction of the alcohol, a product of intermolecular condensation reaction of the alcohol, a product of intermolecular condensation reaction between the alcohol and the partial oxide and a product of intermolecular condensation reaction of the partial oxide, E1 representing a total mass of carbon powder and G1 representing a total mass of cation exchange resin are controlled to satisfy {100×A1/(E1+G1)}?0.05.

Abstract: An object of the present invention is to provide a catalyst-coated membrane suitable for achieving a polymer electrolyte fuel cell that sufficiently prevents a decrease in the initial characteristics and also exhibits sufficient cell performance for a long period of time and has excellent durability. In at least the cathode catalyst layer, the ratio (WP/WCat-C) of the weight of the polymer electrolyte (WP) to the weight of the catalyst-carrying carbon (WCat-C) is decreased from an innermost layer positioned closest to the polymer electrolyte membrane toward an outermost layer positioned farthest from the polymer electrolyte membrane. The ratio (WP/WCat-C) in the innermost layer is 0.8 to 3.0, and the ratio (WP/WCat-C) in the outermost layer is 0.2 to 0.6.

Abstract: The present invention provides a gas diffusion electrode capable of sufficiently preventing not only degradation of MEA during storage but also degradation of initial characteristics and durability during the time period from production to initial use, and a polymer electrolyte fuel cell including the gas diffusion electrode. The gas diffusion electrode includes a catalyst layer in which A1 representing a total mass of organic substance comprising alcohol, a partial oxide of the alcohol, a product of intramolecular dehydrogenation reaction of the alcohol, a product of intermolecular condensation reaction of the alcohol, a product of intermolecular condensation reaction between the alcohol and the partial oxide and a product of intermolecular condensation reaction of the partial oxide, E1 representing a total mass of carbon powder and G1 representing a total mass of cation exchange resin are controlled to satisfy {100×A1/(E1+G1)}?0.05.

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: 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: The present invention provides an electrode for a polymer electrolyte fuel cell comprising a high-performance electrode catalyst particle which is sufficiently coated with a hydrogen ion conductive polymer electrolyte and has a water repellent material suitably supplied thereto for water management. The method of producing the electrode in accordance with the present invention comprises the steps of spraying a solution or dispersion of a hydrogen ion conductive polymer electrolyte into a dry atmosphere in which a catalyst particle comprising an electrically conductive carbon powder carrying a platinum group metal catalyst is flowing, to coat the catalyst particle with the polymer electrolyte, and then spraying a solution or dispersion of a water repellent material to the catalyst particle to attach the water repellent material to the catalyst particle.

Abstract: An object of the present invention is to provide a catalyst-coated membrane suitable for achieving a polymer electrolyte fuel cell that sufficiently prevents a decrease in the initial characteristics and also exhibits sufficient cell performance for a long period of time and has excellent durability. In at least the cathode catalyst layer, the ratio (WP/WCat-C) of the weight of the polymer electrolyte (WP) to the weight of the catalyst-carrying carbon (WCat-C) is decreased from an innermost layer positioned closest to the polymer electrolyte membrane toward an outermost layer positioned farthest from the polymer electrolyte membrane. The ratio (WP/WCat-C) in the innermost layer is 0.8 to 3.0, and the ratio (WP/WCat-C) in the outermost layer is 0.2 to 0.6.

Abstract: In a polymer electrolyte fuel cell of the present invention, at least one of electrodes comprises conductive carbon carrying a platinum group metal catalyst, conductive carbon carrying no catalyst metal and a hydrogen ion-conductive polymer electrolyte. The preferable amount of the conductive carbon carrying no catalyst metal is equivalent to 5 to 50 wt % of the conductive carbon carrying the catalyst metal. Incorporation of the conductive carbon carrying no catalyst metal to the catalyst layer enables reduction in potential concentration on part of electron conduction channels in an electrode, whereby an electrode for a polymer electrolyte fuel cell having an excellent life characteristic can be provided.

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 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 polymer electrolyte fuel cell including a hydrogen-ion-conductive polymer electrolyte membrane, a pair of electrodes sandwiching the membrane, a conductive separator plate having a gas passage for supplying a fuel to one of the electrodes, and a conductive separator plate having a gas passage for supplying an oxidant to the other electrode. The metallic conductive separator plate is a type in which a conductive coat including conductive particles and glass is formed on a surface having a gas passage. As a result, the corrosion of the metallic plate is suppressed and the degradation of the power generation efficiency after extended use is also suppressed.

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.

Abstract: In a polymer electrolyte fuel cell of the present invention, at least one of electrodes comprises conductive carbon carrying a platinum group metal catalyst, conductive carbon carrying no catalyst metal and a hydrogen ion-conductive polymer electrolyte. The preferable amount of the conductive carbon carrying no catalyst metal is equivalent to 5 to 50 wt % of the conductive carbon carrying the catalyst metal. Incorporation of the conductive carbon carrying no catalyst metal to the catalyst layer enables reduction in potential concentration on part of electron conduction channels in an electrode, whereby an electrode for a polymer electrolyte fuel cell having an excellent life characteristic can be provided.

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 from the other electrode toward the electrode catalyst layer of the one of the electrodes.

Abstract: The present invention provides an electrode for a polymer electrolyte fuel cell comprising a high-performance electrode catalyst particle which is sufficiently coated with a hydrogen ion conductive polymer electrolyte and has a water repellent material suitably supplied thereto for water management. The method of producing the electrode in accordance with the present invention comprises the steps of spraying a solution or dispersion of a hydrogen ion conductive polymer electrolyte into a dry atmosphere in which a catalyst particle comprising an electrically conductive carbon powder carrying a platinum group metal catalyst is flowing, to coat the catalyst particle with the polymer electrolyte, and then spraying a solution or dispersion of a water repellent material to the catalyst particle to attach the water repellent material to the catalyst particle.