Abstract: A fuel cell includes: an electrolyte membrane-electrode structure in which electrodes are provided on both surfaces of an electrolyte membrane and a frame member is joined to the outer peripheral portion of the electrolyte membrane; and a pair of separators for sandwiching the electrolyte membrane-electrode structure, wherein an overlapping portion of the outer peripheral portion of the electrode and the inner peripheral portion of the frame member is disposed in a flow field section in which flow field grooves for allowing a reactant gas to flow along the electrode surface of the electrolyte membrane-electrode structure are formed, and is disposed so as not to extend into buffers between the flow field section and passages.

Abstract: In a power generation cell, cathode flow field grooves forming a gas flow field of a cathode separator arranged to face an MEA are formed of first cathode flow field grooves blocked on an outlet side and second cathode flow field grooves blocked on an inlet side. The first cathode flow field grooves and the second cathode flow field grooves are arranged adjacent to each other in the flow field width direction.

Abstract: A fuel cell includes: an electrolyte membrane-electrode structure in which electrodes are provided on both surfaces of an electrolyte membrane and a frame member is joined to the outer peripheral portion of the electrolyte membrane; and a pair of separators for sandwiching the electrolyte membrane-electrode structure, wherein an overlapping portion of the outer peripheral portion of the electrode and the inner peripheral portion of the frame member is disposed in a flow field section in which flow field grooves for allowing a reactant gas to flow along the electrode surface of the electrolyte membrane-electrode structure are formed, and is disposed so as not to extend into buffers between the flow field section and passages.

Abstract: A separator for a fuel cell forms a stacked unit of a power generating cell stacked body. The separator is made up from a connected body of a first bipolar plate and a second bipolar plate that are stacked on each other, and is provided with positioning parts. The positioning parts are disposed at positions overlapping in the stacking direction with respect to each of the first bipolar plate and the second bipolar plate. A first positioning edge portion of the first bipolar plate and a second positioning edge portion of the second bipolar plate are at different positions from each other in a separator surface direction.

Abstract: A resin frame equipped membrane electrode assembly includes an MEA having different sizes of components, and a resin frame member. A resin melt portion is provided for the resin frame member. The inside of a first gas diffusion layer is impregnated with resin as a part of the resin melt portion. A thin portion is provided at an outermost peripheral portion of the resin frame member through a step at an outermost peripheral portion of the resin melt portion, and the thin portion is thinner in a thickness direction than the resin melt portion.

Abstract: A resin frame equipped membrane electrode assembly includes an MEA having different sizes of components, and a resin frame member. A resin melt portion is provided for the resin frame member. The inside of a first gas diffusion layer is impregnated with resin as a part of the resin melt portion. A thin portion is provided at an outermost peripheral portion of the resin frame member through a step at an outermost peripheral portion of the resin melt portion, and the thin portion is thinner in a thickness direction than the resin melt portion.

Abstract: A fuel cell includes a membrane electrode assembly and a metal separator. The membrane electrode assembly includes an electrolyte membrane, first and second electrodes, and a resin frame member. The resin frame member is provided on an outer peripheral portion of the membrane electrode assembly. The metal separator is stacked on the membrane electrode assembly in a stacking direction and includes a reactant gas channel, a reactant gas manifold, and a flat portion. The resin frame member of the membrane electrode assembly has an outer shape to be disposed further inward than the reactant gas manifold and includes a connection channel portion that is disposed outward from an electrode surface and that connects the reactant gas manifold and the reactant gas channel to each other. The flat portion is provided in contact with the connection channel portion.

Abstract: A manufacturing method includes providing a cell stack including fuel cells and has a first end and a second end. A first end plate is provided at the first end of the cell stack. The first end plate has a first end plate through hole. A second end plate is provided at the second end of the cell stack. A connecting member is provided to connect the first end plate and the second end plate. A first knock is inserted into the first end plate through hole and into a first connecting member installing hole. A first seal is located between the first knock and the first end plate in the first end plate through hole. The first end plate is moved in the stacking direction to contact the connecting member. A fastening member is inserted into the first knock.

Abstract: A resin frame equipped membrane electrode assembly includes an MEA having different sizes of components, and a resin frame member. A resin melt portion is provided for the resin frame member. The inside of a first gas diffusion layer is impregnated with resin as a part of the resin melt portion. A thin portion is provided at an outermost peripheral portion of the resin frame member through a step at an outermost peripheral portion of the resin melt portion, and the thin portion is thinner in a thickness direction than the resin melt portion.

Abstract: A method for preparing a fuel cell membrane electrode assembly, where the membrane electrode assembly includes a solid polymer electrolyte membrane and a first electrode and a second electrode provided on both sides of the solid polymer electrolyte membrane. The first electrode and the second electrode each include an electrode catalyst layer and a gas diffusion layer. The method includes forming the first electrode and the second electrode on both sides of the solid polymer electrolyte membrane, providing a preformed resin frame member around the solid polymer electrolyte membrane, overlapping an outer marginal portion of the first electrode and an inner marginal portion of the resin frame member with each other and applying heat and pressure to the overlapped portions of the first electrode and the resin frame member to join the resin frame member around the solid polymer electrolyte membrane.

Abstract: A fuel cell stack includes a stacked body including a plurality of power generation cells stacked in a stacking direction. Insulation members and end plates are provided to sandwich the stacked body therebetween in the stacking direction. A coolant passage is provided between each of the insulation members and each of the end plates. The coolant passage includes a first coolant passage and a second coolant passage. A surface area of a region in which the first coolant passage is provided is larger than a surface area of a region in which the second coolant passage is provided. A flow rate of the coolant flowing through the first coolant passage is larger than a flow rate of the coolant flowing through the second coolant passage.

Abstract: A resin-framed membrane electrode assembly for a fuel cell includes a stepped membrane electrode assembly and a resin frame member. The stepped membrane electrode assembly includes a solid polymer electrolyte membrane, an anode electrode, and a cathode electrode. The resin frame member surrounds an outer periphery of the solid polymer electrolyte membrane and includes an inner protruding portion that protrudes from an inner peripheral base portion toward the cathode electrode and that has a thickness. The inner protruding portion has an adhesive application portion to which an adhesive is applied so as to surround a part of the inner protruding portion. The part is in contact with the stepped membrane electrode assembly. A thickness of a cathode diffusion layer is larger than a thickness of an anode diffusion layer.

Abstract: A method for preparing a fuel cell membrane electrode assembly, where the membrane electrode assembly includes a solid polymer electrolyte membrane and a first electrode and a second electrode provided on both sides of the solid polymer electrolyte membrane. The first electrode and the second electrode each include an electrode catalyst layer and a gas diffusion layer. The method includes forming the first electrode and the second electrode on both sides of the solid polymer electrolyte membrane, providing a preformed resin frame member around the solid polymer electrolyte membrane, overlapping an outer marginal portion of the first electrode and an inner marginal portion of the resin frame member with each other and applying heat and pressure to the overlapped portions of the first electrode and the resin frame member to join the resin frame member around the solid polymer electrolyte membrane.

Abstract: A manufacturing method includes providing a cell stack including fuel cells and has a first end and a second end. A first end plate is provided at the first end of the cell stack. The first end plate has a first end plate through hole. A second end plate is provided at the second end of the cell stack. A connecting member is provided to connect the first end plate and the second end plate. A first knock is inserted into the first end plate through hole and into a first connecting member installing hole. A first seal is located between the first knock and the first end plate in the first end plate through hole. The first end plate is moved in the stacking direction to contact the connecting member. A fastening member is inserted into the first knock.

Abstract: A fuel cell includes a membrane electrode assembly, a separator, a reactant gas channel, a reactant gas manifold, and a buffer portion. The buffer portion includes a first buffer region and a second buffer region. The second buffer region is located in a vicinity of the reactant gas manifold and is deeper than the first buffer region in a stacking direction. Embossed portion groups are arranged in a plurality of rows in the second buffer region between the reactant gas manifold and the first buffer region. Each of the embossed portion groups includes a plurality of embossed portions. A disposition density of the plurality of embossed portions of one of the embossed portion groups in a vicinity of the reactant gas manifold is lower than a disposition density of the plurality of embossed portions of another of the embossed portion groups in a vicinity of the first buffer region.

Abstract: A resin frame equipped membrane electrode assembly includes an MEA having different sizes of components, and a resin frame member. A resin melt portion is provided for the resin frame member. The inside of a first gas diffusion layer is impregnated with resin as a part of the resin melt portion. A thin portion is provided at an outermost peripheral portion of the resin frame member through a step at an outermost peripheral portion of the resin melt portion, and the thin portion is thinner in a thickness direction than the resin melt portion.

Abstract: A fuel cell stack includes a stacked body including a plurality of power generation cells stacked in a stacking direction. Insulation members and end plates are provided to sandwich the stacked body therebetween in the stacking direction. A coolant passage is provided between each of the insulation members and each of the end plates. The coolant passage includes a first coolant passage and a second coolant passage. A surface area of a region in which the first coolant passage is provided is larger than a surface area of a region in which the second coolant passage is provided. A flow rate of the coolant flowing through the first coolant passage is larger than a flow rate of the coolant flowing through the second coolant passage.

Abstract: A fuel cell stack includes a first power generation unit and a second power generation unit. Wave-like first fuel gas flow passages of the first power generation unit and wave-like first fuel gas flow passages of the second power generation unit are set to mutually different phases. The ends of the first fuel gas flow passages form linear flow passage grooves that linearly extend in the wavelength direction from the center of the width of the wave-form amplitude.

Abstract: A fuel cell stack includes a first power generation unit and a second power generation unit. Wave-like first fuel gas flow passages of the first power generation unit and wave-like first fuel gas flow passages of the second power generation unit are set to mutually different phases. The ends of the first fuel gas flow passages form linear flow passage grooves that linearly extend in the wavelength direction from the center of the width of the wave-form amplitude.

Abstract: A fuel cell includes a membrane electrode assembly and a metal separator. The membrane electrode assembly includes an electrolyte membrane, first and second electrodes, and a resin frame member. The resin frame member is provided on an outer peripheral portion of the membrane electrode assembly. The metal separator is stacked on the membrane electrode assembly in a stacking direction and includes a reactant gas channel, a reactant gas manifold, and a flat portion. The resin frame member of the membrane electrode assembly has an outer shape to be disposed further inward than the reactant gas manifold and includes a connection channel portion that is disposed outward from an electrode surface and that connects the reactant gas manifold and the reactant gas channel to each other. The flat portion is provided in contact with the connection channel portion.