Abstract: A catalyst-coated membrane that includes an anode catalyst layer, a cathode catalyst layer, and a hydrogen ion conductive polymer electrolyte membrane interposed between the anode catalyst layer and the cathode catalyst layer, a peripheral area of at least one of the anode catalyst layer and the cathode catalyst layer is provided with a decrease portion in which the mass of the electrode catalyst per unit area of the catalyst layer decreases from the inner side toward the outer side.

Abstract: A method for manufacturing a membrane-electrode assembly of the present invention includes: a reinforcing member disposing step of disposing a reinforcing member (104A, 104B), whose frame portion is formed to surround an opening of the reinforcing member, on a polymer electrolyte membrane (102) such that the frame portion covers a peripheral portion of at least one surface of the polymer electrolyte membrane; a catalyst layer applying step of applying a coating of a catalyst layer (109A, 109B) on at least an entire surface of the polymer electrolyte membrane (102) which surface is exposed from the opening of the reinforcing member (104A, 104B); and a gas diffusion layer disposing step of disposing a gas diffusion layer (114A, 114B) such that the gas diffusion layer covers the catalyst layer (109A, 109B).

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: In a conventional polymer membrane electrode assembly, particularly when operated for a long period of time, a portion of the polymer electrolyte membrane to be in contact with the gas diffusion layer has suffered significant degradation. In order to address this, in a membrane electrode assembly including a hydrogen ion conductive polymer electrolyte membrane, a pair of catalyst layers arranged on both surfaces of the polymer electrolyte membrane, and a pair of gas diffusion layers, each including a fibrous substrate, arranged on the outer surfaces of the catalyst layers, a thickness TA of a center portion that faces the catalyst layer and a thickness TB of a peripheral portion surrounding the center portion are set to satisfy a expression (1): 0.7?TB/TA?0.9.

Abstract: A method for manufacturing a membrane-electrode assembly of the present invention includes: a reinforcing member disposing step of disposing a reinforcing member (104A, 104B), whose frame portion is formed to surround an opening of the reinforcing member, on a polymer electrolyte membrane (102) such that the frame portion covers a peripheral portion of at least one surface of the polymer electrolyte membrane; a catalyst layer applying step of applying a coating of a catalyst layer (109A, 109B) on at least an entire surface of the polymer electrolyte membrane (102) which surface is exposed from the opening of the reinforcing member (104A, 104B); and a gas diffusion layer disposing step of disposing a gas diffusion layer (114A, 114B) such that the gas diffusion layer covers the catalyst layer (109A, 109B).

Abstract: The present invention provides a catalyst-coated membrane and a membrane-electrode assembly that can easily and surely achieve a polymer electrolyte fuel cell having excellent durability, in which the decomposition/degradation of a polymer electrolyte membrane can be suppressed, and a decrease in initial characteristics can be prevented sufficiently for a long period of time even when the polymer electrolyte fuel cell is frequently started and stopped. In the catalyst-coated membrane that includes an anode catalyst layer, a cathode catalyst layer, and a hydrogen ion conductive polymer electrolyte membrane interposed between the anode catalyst layer and the cathode catalyst layer, a peripheral area of at least one of the anode catalyst layer and the cathode catalyst layer is provided with a decrease portion in which the mass of the electrode catalyst per unit area of the catalyst layer decreases from the inner side toward the outer side.

Abstract: To provide a polymer electrolyte membrane having excellent size stability and excellent mechanical strength that can sufficiently prevent the size change due to the swelling condition, the displacement of the polymer electrolyte membrane and the formation of wrinkles during the production of the polymer electrolyte fuel cell, and can prevent damage during the production and operation of the polymer electrolyte fuel cell. In a composite electrolyte membrane including a porous reinforcement layer made of a resin and an electrolyte layer made of a polymer electrolyte and laminated at least one main surface of the reinforcement layer, the direction having a high tensile modulus of elasticity in the reinforcement layer is substantially corresponded with the direction having a high rate of size change in the electrolyte layer.

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 conventional polymer membrane electrode assembly, particularly when operated for a long period of time, a portion of the polymer electrolyte membrane to be in contact with the gas diffusion layer has suffered significant degradation. In order to address this, in a membrane electrode assembly including a hydrogen ion conductive polymer electrolyte membrane, a pair of catalyst layers arranged on both surfaces of the polymer electrolyte membrane, and a pair of gas diffusion layers, each including a fibrous substrate, arranged on the outer surfaces of the catalyst layers, a thickness TA of a center portion that faces the catalyst layer and a thickness TB of a peripheral portion surrounding the center portion are set to satisfy a expression (1): 0.7?TB/TA?0.9.

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: To provide a polymer electrolyte membrane having excellent size stability and excellent mechanical strength that can sufficiently prevent the size change due to the swelling condition, the displacement of the polymer electrolyte membrane and the formation of wrinkles during the production of the polymer electrolyte fuel cell, and can prevent damage during the production and operation of the polymer electrolyte fuel cell. In a composite electrolyte membrane including a porous reinforcement layer made of a resin and an electrolyte layer made of a polymer electrolyte and laminated at least one main surface of the reinforcement layer, the direction having a high tensile modulus of elasticity in the reinforcement layer is substantially corresponded with the direction having a high rate of size change in the electrolyte layer.

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: A fuel cell system is disclosed, including a fuel cell configured to generate an electric power using a fuel gas and an oxidizing gas supplied to the fuel cell, and a total enthalpy heat exchanger configured to heat and humidify the oxidizing gas using heat and water exhausted from the fuel cell, wherein the total enthalpy heat exchanger is capable of removing impurities contained in the oxidizing gas from the oxidizing gas.