Abstract: A fuel cell stack includes a stacked body, a first terminal plate, a first insulator, a first end plate, a second terminal plate, a second insulator, a second end plate, a fluid manifold, a fluid channel, a fluid hole, a first connection passage, and a second connection passage. The stacked body includes a plurality of separators and a membrane electrode assembly. The plurality of separators and the membrane electrode assembly are stacked in a stacking direction. The membrane electrode assembly includes an electrolyte membrane and a pair of electrodes sandwiching the electrolyte membrane therebetween. The stacked body has a first end and a second end opposite to the first end in the stacking direction. The first terminal plate, the first insulator, and the first end plate are disposed at the first end of the stacked body.

Abstract: A fuel cell includes a power generation unit. A first resin frame member is provided in an outer portion of a first membrane electrode assembly of the power generation unit. The first metal separator has a heating portion subjected to spot heating from a surface of the first metal separator for allowing the first resin frame member to be melted partially. The first metal separator and the first membrane electrode assembly are welded together by a plurality of welding portions to form a first structural body.

Abstract: A fuel cell includes a cathode side separator. An oxygen-containing gas flow field is formed on a surface of the cathode side separator. The oxygen-containing gas flow field includes an inlet channel having a plurality of flow grooves connected to the oxygen-containing gas supply passage, an outlet channel having a plurality of flow grooves connected to the oxygen-containing gas discharge passage, and an intermediate channel having flow grooves with both ends connected to the inlet channel and the outlet channel respectively. The flow grooves of the outlet channel are longer than the flow grooves of the inlet channel, and the flow grooves of the outlet channel are narrowed toward the oxygen-containing gas discharge passage.

Abstract: A fuel cell includes a cathode side separator. An oxygen-containing gas flow field is formed on a surface of the cathode side separator. The oxygen-containing gas flow field includes an inlet channel having a plurality of flow grooves connected to the oxygen-containing gas supply passage, an outlet channel having a plurality of flow grooves connected to the oxygen-containing gas discharge passage, and an intermediate channel having flow grooves with both ends connected to the inlet channel and the outlet channel respectively. The flow grooves of the outlet channel are longer than the flow grooves of the inlet channel, and the flow grooves of the outlet channel are narrowed toward the oxygen-containing gas discharge passage.

Abstract: A fuel cell includes a membrane electrode assembly, and a first separator and a second separator sandwiching the membrane electrode assembly. The membrane electrode assembly has a resin frame member, and an inlet buffer is provided on the resin frame member adjacent to the fuel gas supply passage. The inlet buffer includes a first buffer area adjacent to the fuel gas supply passage and a second buffer area adjacent to a fuel gas flow field. The opening dimension of the first buffer area in a stacking direction is larger than the opening dimension of the second buffer area in the stacking direction.

Abstract: A fuel cell includes a solid polymer electrolyte membrane, and a cathode separator and an anode separator sandwiching a solid polymer electrolyte membrane therebetween. The fuel cell includes an oxidant gas channel including a plurality of wave-shaped channel portions extending in a horizontal direction. Part of one of the plurality of wave-shaped channel portions that is disposed at the lower end in the vertical direction protrude downward from a planar region of electrode catalyst layers, i.e. a power generation region, in the vertical direction.

Abstract: A fuel cell stack includes a plurality of fuel cells each including a first separator, a second separator and a membrane electrode assembly. A first reactant gas manifold of the first separator has an elongated opening extending along a ridge line of a first buffer portion and has an end wall surface that is located at an end of the first reactant gas manifold of the first separator near a middle portion of the first buffer portion and that is a convex curved surface. The convex curved surface and the first buffer portion are connected to each other through a channel that is bent or curved.

Abstract: A fuel cell stack has an asymmetrical triangular inlet buffer. An inlet connection channel connects a coolant supply passage on the upper side and the inlet buffer, and an inlet connection channel connects a coolant supply passage on the lower side and the inlet buffer. The number of flow grooves in the inlet connection channel is different from the number of flow grooves in the inlet connection channel.

Abstract: A cell unit of a fuel cell includes a first separator, a first membrane electrode assembly, a second separator, a second membrane electrode assembly, and a third separator. Resin connecting sections are provided in the outer circumferential ends of the first separator, the second separator, and the third separator. A coupling pin is molded integrally with the resin connecting section of the first separator. A first hole and a second hole are formed on both sides of the coupling pin for selectively inserting a rebuilt pin into either of the first and second holes. A hole for inserting the coupling pin is formed at the center, and the first hole and the second hole are formed on both sides of the hole, in each of the resin connecting sections of the second and third separators.

Abstract: A fuel cell includes a membrane electrode assembly, a first separator, and a second separator. The second separator has a fuel gas flow field connected to a fuel gas supply passage and a fuel gas discharge passage. The fuel gas flow field includes a plurality of corrugated flow grooves and a flat flow field. The corrugated flow grooves extend in the horizontal direction, respectively, and are arranged in the direction of the gravity. The flat flow field is provided within a power generation area, at the lowermost position in the direction of the gravity, and extends in the horizontal direction.

Abstract: A fuel cell includes an electrolyte-electrode assembly, a frame member, a first separator, and a second separator. The frame member is provided to face a first surface of the second separator and includes a resin wall which forms a periphery of a first reactant gas passage. The resin wall has a thin-walled portion which overlaps with a cooling medium connecting portion in a stacking direction and which protrudes toward the first reactant gas passage in the stacking direction by a first dimension from a surface of the frame member. Another portion of the resin wall protrudes toward the second separator in the stacking direction by a second dimension from the surface of the frame member. The first dimension is smaller than the second dimension.

Abstract: A power generation unit of a fuel cell includes a first metal separator, a first membrane electrode assembly, a second metal separator, a second membrane electrode assembly, and a third metal separator. A bypass limiting section is provided at an end of the coolant flow field for preventing a coolant from bypassing the coolant flow field. The bypass limiting section includes a corrugated section formed integrally with the first metal separator and a corrugated section formed integrally with the third metal separator adjacent to the first metal separator, and contacting the corrugated section.

Abstract: A fuel cell includes a membrane electrode assembly, a first separator, and a second separator. The membrane electrode assembly includes a first electrode, a second electrode, a resin frame member, and an electrolyte membrane. The resin frame member includes a first surface, a second surface, a first buffer portion, and a second buffer portion. The first buffer portion is provided on the first surface of the resin frame member. The second buffer portion is provided on the second surface of the resin frame member. The second buffer portion is independent from the first buffer portion.

Abstract: A fuel cell is formed by sandwiching a membrane electrode assembly between a first separator and a second separator. An outlet connection channel connecting a fuel gas flow field with a fuel gas discharge passage is provided in the first separator. The outlet connection channel has a plurality of discharge holes extending through the first separator. The discharge holes are arranged in the direction of gravity. The discharge hole at the lowermost position has an opening elongated downward to have an opening area larger than opening areas of the other discharge holes above and adjacent to the discharge hole at the lowermost position.

Abstract: A fuel cell includes a membrane electrode assembly and a separator. The separator includes a water accumulation portion including at least one of a buffer portion, a lowermost channel groove, a channel junction portion, and a bypass channel. The buffer portion is connected to a reactant gas channel through which a reactant gas is to flow along a power generation surface of the membrane electrode assembly. The channel groove is provided in the reactant gas channel and located at a lowest position in the reactant gas channel in a direction of gravity when the membrane electrode assembly and the separator are in an upright position. Channel grooves of the reactant gas channel are joined in the channel junction portion. The membrane electrode assembly includes a water impermeable layer which is disposed outside of a power generation region and which faces the water accumulation portion.

Abstract: A unit cell of a fuel cell is formed by sandwiching a membrane electrode assembly between a first metal separator and a second metal separator. The membrane electrode assembly includes a solid polymer electrolyte membrane having a reinforcement member on both surfaces of the outer end of the solid polymer electrolyte membrane. Frame members are provided on the reinforcement member outside an anode, and a fuel gas inlet channel and a fuel gas outlet channel are formed by the frame members, at positions corresponding to a fuel gas inlet buffer and a fuel gas outlet buffer.

Abstract: An electrolyte membrane/electrode structure constituting a fuel cell comprises a solid polymer electrolyte membrane, an anode side electrode and a cathode side electrode sandwiching the solid polymer electrolyte membrane. The anode side electrode is provided with an electrode catalyst layer and a gas diffusion layer abutting on one side of the solid polymer electrolyte membrane and exposing the outer circumference thereof in the shape of a frame, and the cathode side electrode is provided with an electrode catalyst layer and a gas diffusion layer abutting on the other side of the solid polymer electrolyte membrane. A reinforcing sheet member is arranged on the frame-shaped surface of the solid polymer electrolyte membrane projecting from the outer circumference of the gas diffusion layer.

Abstract: A fuel cell includes a membrane electrode assembly, and a first separator and a second separator sandwiching the membrane electrode assembly. The membrane electrode assembly has a resin frame member, and an inlet buffer is provided on the resin frame member adjacent to the fuel gas supply passage. The inlet buffer includes a first buffer area adjacent to the fuel gas supply passage and a second buffer area adjacent to a fuel gas flow field. The opening dimension of the first buffer area in a stacking direction is larger than the opening dimension of the second buffer area in the stacking direction.

Abstract: A fuel cell unit configuring a fuel cell is provided with a first separator, a first electrolyte film/electrode body, a second separator, a second electrolyte film/electrode body, and a third separator. Resin guide members are provided on the outer periphery of the first separator, the second separator, and the third separator. The resin guide members have outer peripheral ends which protrude outwards, and in the aforementioned resin guide members are formed concave reliefs which are spaced inwards from the aforementioned outer peripheral ends.

Abstract: A cell unit of a fuel cell includes a first membrane electrode assembly, a first metal separator, a second membrane electrode assembly, and a second metal separator. Resin frame members are provided at outer ends the first and second membrane electrode assemblies. A dual seal provided on the resin frame member includes an outer seal member and an inner seal member. A front end of the outer seal member contacts the resin frame member, and a front end of the inner seal member contacts the outer end of the first metal separator. The outer seal member and the outer seal member have the same height.