Abstract: A separator for a fuel cell includes protrusions spaced apart from each other. The protrusions are configured to contact a power generation portion. The separator includes a gas passage that extends between two adjacent ones of the protrusions. The gas passage includes ribs that protrude toward the power generation portion. The ribs include first ribs spaced apart from each other in an arrangement direction of the protrusions and a second rib located between adjacent ones of the first ribs in the arrangement direction. A downstream end of each of the first ribs includes a separated portion separated from the power generation portion. An upstream end of the second rib includes an inclined portion inclined so as to become closer to the power generation portion toward a downstream side. At least part of the inclined portion is located downstream of at least part of the separated portion.

Abstract: A separator for a fuel cell includes protrusions that extend in parallel and are spaced apart from each other. The protrusions are configured to contact a power generation portion. The separator includes a gas passage that extends between two adjacent ones of the protrusions along the protrusions. The gas passage is configured to allow reactant gas to flow through the gas passage. The gas passage includes at least one rib that protrudes toward the power generation portion and extends in an extending direction of the gas passage. A downstream end of the rib includes a gradually-changing portion that gradually becomes farther from the power generation portion toward a downstream side.

Abstract: A separator for a fuel cell includes protrusions and gas passage portions. The protrusions each include a contact surface configured to contact a power generation portion. The gas passage portions are each arranged between two adjacent ones of the protrusions. An upstream side and a downstream side are defined with reference to a direction in which reactant gas flows through the gas passage portions. The protrusions each include a downstream end. The contact surfaces of the protrusions each include a first groove extending along an extending direction of the protrusions. The downstream end of each of the protrusions includes a separation surface. The separation surface is continuous with the contact surface on the downstream side and separated from the power generation portion. The separation surface includes a second groove that is continuous with the first groove.

Abstract: A fuel cell stack includes stacked cells, each including a sheet-shaped power generation portion, two separators, a gas passage defining plate that includes a gas passage portion through which reactant gas flows, and a frame member that includes a supply port and a discharge port. The gas passage portion includes opposing portions extended in a flow direction of the reactant gas and arranged in parallel in an orthogonal direction. A main passage is defined between each opposing portion and the power generation portion. The gas passage portion includes a first passage portion adjacent to the supply port in the flow direction and a second passage portion adjacent to the first passage portion in the orthogonal direction. The main passages of the second passage portion each have a larger cross-sectional flow area than the main passages of the first passage portion.

Abstract: A fuel cell stack includes stacked cells, each including a sheet-shaped power generation portion, two separators, a gas passage defining plate that includes a gas passage portion through which reactant gas flows, and a frame member that includes a supply port and a discharge port. The gas passage portion includes opposing portions extended in a flow direction of the reactant gas and arranged in parallel in an orthogonal direction and wavy portions each having a wavy cross- sectional shape orthogonal to the orthogonal direction. The gas passage portion includes a first passage portion adjacent to the supply port in the flow direction and a second passage portion adjacent to the first passage portion in the orthogonal direction. The connection passages of the second passage portion each have a larger cross-sectional flow area than the connection passages of the first passage portion.

Abstract: A gas flow passage formation plate includes a plurality of projections arranged in a first direction and a second direction. The projections project toward a membrane electrode assembly. The gas flow passage formation plate further includes a gas flow passage, a water flow passage, and a plurality of openings. The gas flow passage is formed by a portion of the gas flow passage formation plate at a side opposing the membrane electrode assembly including regions between two adjacent projections. The water flow passage is formed by a portion of the gas flow passage formation plate at a side opposing a partition plate including the inside of the projections. The openings are each formed in a side wall of the projection connecting inside and outside of the projection. Each opening is arranged at only one location in one projection.

Abstract: A gas channel forming plate is arranged between a membrane electrode assembly and a flat separator base. The gas channel forming plate includes gas channels arranged on a surface that faces the membrane electrode assembly, water channels each formed on the back side of the protrusion between an adjacent pair of the gas channels, communication passages that connect the gas channels and the water channels to each other, and guide portions formed by causing an inner wall surface of a gas channel to protrude inward in the gas channel. The guide portions are formed such that the upstream edge of each communication passage is arranged in a range in which, in the velocity vector of the gas flowing in the gas channel, the directional component directed from the side corresponding to the membrane electrode assembly toward the flat separator base has a positive value.

Abstract: A gas flow passage formation plate includes a plurality of projections arranged in a first direction and a second direction. The projections project toward a membrane electrode assembly. The gas flow passage formation plate further includes a gas flow passage, a water flow passage, and a plurality of openings. The gas flow passage is formed by a portion of the gas flow passage formation plate at a side opposing the membrane electrode assembly including regions between two adjacent projections. The water flow passage is formed by a portion of the gas flow passage formation plate at a side opposing a partition plate including the inside of the projections. The openings are each formed in a side wall of the projection connecting inside and outside of the projection. Each opening is arranged at only one location in one projection.

Abstract: A gas flow passage formation plate includes projections arranged in a first direction and a second direction orthogonal to the first direction. The gas flow passage formation plate includes a gas flow passage formed by a portion of the gas flow passage formation plate at a side opposing a membrane electrode assembly including regions between adjacent projections, a water flow passage formed by a portion of the gas flow passage formation plate at a side opposing a partition plate including inside of the projections, and openings each formed in a side wall of the projection connecting inside and outside of the projection. In a state in which the openings sandwich the gas flow passage, the openings are arranged so as not to oppose and overlap each other in a direction orthogonal to a direction in which gas flows.

Abstract: A gas flow passage-forming member is disposed between a membrane electrode and gas diffusion layer assembly and a separator of a fuel cell, and the gas flow passage-forming member is configured to form a gas flow passage. The gas flow passage-forming member has a corrugated shape such that groove portions and ridge portions are provided on each of a front side and a back side of the gas flow passage-forming member. The groove portions each serve as the gas flow passage. The gas flow passage-forming member has communication holes providing communication between the front side and the back side, and the communication holes are provided in a region downstream of an upstream region in a gas flow direction. The upstream region is a non-communication region with no communication hole.

Abstract: A gas flow passage-forming member is disposed between a membrane electrode and gas diffusion layer assembly and a separator of a fuel cell, and the gas flow passage-forming member is configured to form a gas flow passage. The gas flow passage-forming member has a corrugated shape such that groove portions and ridge portions are provided on each of a front side and a back side of the gas flow passage-forming member. The groove portions each serve as the gas flow passage. The gas flow passage-forming member has communication holes providing communication between the front side and the back side, and the communication holes are provided in a region downstream of an upstream region in a gas flow direction. The upstream region is a non-communication region with no communication hole.

Abstract: A gas channel forming plate is arranged between a membrane electrode assembly and a flat separator base. The gas channel forming plate includes gas channels arranged on a surface that faces the membrane electrode assembly, water channels each formed on the back side of the protrusion between an adjacent pair of the gas channels, communication passages that connect the gas channels and the water channels to each other, and guide portions formed by causing an inner wall surface of a gas channel to protrude inward in the gas channel. The guide portions are formed such that the upstream edge of each communication passage is arranged in a range in which, in the velocity vector of the gas flowing in the gas channel, the directional component directed from the side corresponding to the membrane electrode assembly toward the flat separator base has a positive value.

Abstract: To achieve a flat member for fuel cells in which the grain size of titanium is optimized to suppress local elongation and to reduce the siding distance to a punching die, enabling a reduction in ablation of the punching die. The flat member for fuel cells is an expand passage 10a or a separator 10b, and punched out portions 13, 14 are formed in the flat member by, for example, punch pressing. The flat member includes titanium or an alloy of titanium, and the titanium has an average grain size of 15.9 ?m or less.

Abstract: Each of collectors 22 of an electrode structure 20, which partially constitutes a polymer electrolyte fuel cell, is formed from a metal lath MR having a large number of through-holes. A stopping portion 22a in which the through-holes are reduced in diameter is formed at a peripheral end portion of the collector 22. The peripheral end portion of the collector 22 is folded; subsequently, the folded peripheral end portion is pressed, thereby forming the stopping portion 22a. A resin seal portion 23 for sealing introduced fuel gas and oxidizer gas is formed integrally with the stopping portions 22a by insert molding which is performed such that an injected molten resin encloses the stopping portions 22a. The resin seal portion 23 formed integrally with the stopping portions 22a can reliably prevent inflow of the molten resin toward central portions of the collectors 22.