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 the outer ends of the first and second membrane electrode assemblies. Coolant connection channels including a plurality of grooves is formed in each of the resin frame members. The grooves of the coolant connection channels of the cell unit and grooves of coolant connection channels of a cell unit that is adjacent to the cell unit in the stacking direction are offset from each other, and are not overlapped with each other in the stacking direction.

Abstract: A fuel cell stack includes a plurality of power generation units, a reactant gas channel, and a coolant channel. The plurality of power generation units are stacked in a stacking direction to provide a stacked body and each includes a first separator, a first electrolyte electrode assembly, a second separator, a second electrolyte electrode assembly, and a third separator. The first electrolyte electrode assembly is provided on the first separator. The second separator is provided on the first electrolyte electrode assembly. The second electrolyte electrode assembly is provided on the second separator. The first electrolyte electrode assembly and the second electrolyte electrode assembly each include an electrolyte and a pair of electrodes sandwiching the electrolyte therebetween. The third separator is provided on the second electrolyte electrode assembly.

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 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 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 fuel cell stack. A fuel cell stack, an example of the fuel cell stack, is configured by alternately overlaying first electricity generating units and second electricity generating units in the horizontal direction. The first electricity units are each provided with a first fuel gas flow path, a first oxidant gas flow path, a second fuel gas flow path, and a second oxidant gas flow path, and the flow paths are set to the same phase in the overlaying direction. The second electricity generating units are each provided with a first fuel gas flow path, a first oxidant gas flow path, a second fuel gas flow path, and a second oxidant gas flow path which are set to the same phase in the overlaying direction and are set to a phase different from the phase of the flow paths of the first electricity generating units.

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 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 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 coolant supply passage, a coolant discharge passage, and an air-releasing passage extend through first and second metal plates of a metal separator in a stacking direction of the first and second metal plates. The coolant supply passage and the coolant discharge passage are provided at vertically middle positions of opposite horizontal ends of the separator. A coolant flow field is connected between the coolant supply passage and the coolant discharge passage. The air-releasing passage for releasing air from the coolant flow field is formed above the coolant discharge passage. At least part of the air-releasing passage is positioned above the top of the coolant flow field.

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 the outer ends of the first and second membrane electrode assemblies. Coolant connection channels including a plurality of grooves is formed in each of the resin frame members. The grooves of the coolant connection channels of the cell unit and grooves of coolant connection channels of a cell unit that is adjacent to the cell unit in the stacking direction are offset from each other, and are not overlapped with each other in the stacking direction.

Abstract: A fuel cell includes an electrolyte electrode assembly, an inner seal member, an outer seal member, a metal separator, and a cell voltage monitor terminal. The electrolyte electrode assembly includes an electrolyte, a pair of electrodes, and a resin frame member. The inner seal member extends around an electrode surface. The outer seal member extends around an outer periphery of the inner seal member. The inner seal member and the outer seal member are disposed on the resin frame member. The cell voltage monitor terminal is embedded in the resin frame member. The cell voltage monitor terminal includes an exposed portion provided between the inner seal member and the outer seal member. The exposed portion is in contact with the metal separator adjacent to the exposed portion.

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. A resin frame member is provided integrally with an outer circumference of the first membrane electrode assembly. An oxygen-containing gas supply passage, a fuel gas supply passage, a coolant supply passage, an oxygen-containing gas discharge passage, a fuel gas discharge passage, and a coolant discharge passage extend through the resin frame member in a stacking direction. At each of both ends of the resin frame member in a longitudinal direction, a pair of projections are provided. The projections protrude toward both sides in a lateral direction.

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. Frames are provided at outer circumferences of the first and second membrane electrode assemblies. An oxygen-containing gas supply passage and a fuel gas supply passage, and an oxygen-containing gas discharge passage and a fuel gas discharge passage are provided in one pair of opposite sides of the frames, and a pair of coolant supply passages and a pair of coolant discharge passages are provided in the other pair of opposite sides of the frames at distances from one another.

Abstract: An assembling operation of a fuel cell is effectively simplified. With the simple and economical structure, the desired sealing function is achieved. The fuel cell (10) includes a membrane electrode assembly (14) and first and second metal separators (16, 18) sandwiching the membrane electrode assembly (14). Connection channels (28a, 28b) are provided on the first metal separator (16). The connection channels (28a, 28b) connect the oxygen-containing gas supply passage (20a) and the oxygen-containing gas discharge passage (20b) to the oxygen-containing gas flow field (26). The membrane electrode assembly (14) has first overlapping portions (66a, 66b) overlapped on the connection channels (28a, 28b) for sealing the connection channels (28a, 28b). The first overlapping portions (66a, 66b) comprise, in effect, a gas diffusion layer.

Abstract: A fuel cell is formed by stacking a membrane electrode assembly and separators alternately. Each of the separators includes first and second metal plates. A coolant flow field is formed between the first metal plate of the fuel cell and the second metal plate of the adjacent fuel cell. A folded section is provided around a coolant supply passage by folding the second metal plate. The folded section forms an inlet which enlarges the sectional area of an opening as a fluid passage between the coolant supply passage and the coolant flow field.