Abstract: A first metal separator of a fuel cell comprises a metal plate, and a first seal member is formed integrally on both surfaces of an outer edge of the metal plate. A first rib having a frame shape is provided around an oxygen-containing gas supply passage or the like of the metal plate. The first rib has a rib surface spaced away from an inner end surface of the metal plate around the oxygen-containing gas supply passage or the like, toward the oxygen-containing gas supply passage or the like.

Abstract: A fuel cell is formed by stacking first cell units and second cell units alternately. An inlet buffer and an outlet buffer are formed on a surface of a first metal separator of the first cell unit. Bosses are provided in the inlet buffer and the outlet buffer of the first metal separator. An inlet buffer and an outlet buffer are formed on a surface of the second metal separator of the first cell unit. Continuous guide ridges are formed in the inlet buffer and the outlet buffer of the second metal separator. The bosses and the continuous guide ridges are provided at positions overlapped with each other in the stacking direction.

Abstract: Coolant supply passages and coolant discharge passages, for example, two respectively thereof, are disposed on upper and lower side portions of a first end plate of a fuel cell stack. Grooves are formed on a surface of the first end plate for establishing communication between each of the coolant supply passages and the coolant discharge passages. Air, which is introduced upwardly of the coolant discharge passages, is discharged to the coolant supply passages.

Abstract: A fuel cell stack includes unit cells. At one side of the unit cells, an oxygen-containing gas supply passage and a fuel gas discharge passage having different opening areas are provided. At the one side of the unit cells, a recess is provided near the fuel gas discharge passage having a relatively small opening area. A cell voltage terminal is provided in the recess such that the cell voltage terminal does not protrude outwardly from the side of the unit cells.

Abstract: A fuel cell stack has fuel cell units. Each of the fuel cell units includes first and second membrane electrode assemblies and first to third separators sandwiching the first and second membrane electrode assemblies. A positioning mechanism is used for positioning the first to third separators in alignment with each other. The positioning mechanism includes a first protruded portion and a second protruded portion. The first protruded portion protrudes from one surface of the second separator for positioning the first separator. The second protruded portion protrudes from the other surface of the second separator for positioning the third separator.

Abstract: A unit cell of a fuel cell includes a membrane electrode assembly and an anode side metal separator and a cathode side metal separator sandwiching the membrane electrode assembly. A plurality of first supply holes and a plurality of second supply holes extend through a channel unit of the anode side metal separator, and the channel unit connects a fuel gas supply passage and a fuel gas flow field. A fuel gas from the fuel gas supply passage flows into the first supply holes, and flows through an inlet connection channel. The fuel gas flows into the second supply holes connected to an end of the inlet connection channel. The fuel gas flows toward the side of the membrane electrode assembly, and then, the fuel gas is supplied to an anode.

Abstract: Each of power generation units of a fuel cell according to the present invention is formed by stacking a first metal separator, a first membrane electrode assembly, a second metal separator, a second membrane electrode assembly, and a third metal separator together. The power generation unit has therein a first oxygen-containing gas flow field, a first fuel gas flow field, a second oxygen-containing gas flow field, and a second fuel gas flow field. The number of flow grooves in the first oxygen-containing gas flow field is different from that of flow grooves in the second oxygen-containing gas flow field, and the number of flow grooves in the first fuel gas flow field is different from that of flow grooves in the second fuel gas flow field.

Abstract: A fuel cell has a unit cell in which a membrane electrode assembly, in which a pair of electrodes are provided on either side of an electrolyte membrane, is provided between a first separator and a second separator. Pin insertion holes are respectively provided in a plurality of portions in an outer periphery of each of the first and the second separators, and the pin insertion holes of the first separators are respectively coaxial with those of the second separator. A leg portion of a cell fastening pin made of resin is inserted through each pair of the coaxial pin insertion holes of the first and the second separators. The unit cell is fastened by fitting a flange portion formed at an end of the leg portion to the first separator, and fitting a hook portion formed at the other end of the leg portion to the second separator.

Abstract: Anodes are provided on a porous resin film, a polymer electrolyte membrane is provided on the anodes, and cathodes are provided on the polymer electrolyte membrane to form a plurality of membrane electrode assemblies as power generation units. An electrically conductive member is connected to the cathode of a membrane electrode assembly, and a metal film is electrically connected to the anode of an adjacent membrane electrode assembly. The electrically conductive member has an expansion connected to the metal film. The cathode of the membrane electrode assembly and the anode of the adjacent membrane electrode assembly are electrically connected by the electrically conductive member and the metal film.

Abstract: This fuel cell stack includes: a coolant-supplying penetration hole and a coolant-discharging penetration hole each communicating with a coolant passage and each penetrates unit fuel cells in a stacking direction. A coolant-supplying penetration hole and a coolant-discharging penetration hole are arranged in a horizontal direction opposing with each other so as to sandwich a power generating region. The fuel cell stack further includes: an air draining penetration hole communicating with the coolant passage and arranged such that at least one part thereof is located at a higher position than an uppermost position of the coolant passage, and penetrates the unit fuel cells in the stacking direction; and a coolant draining penetration hole communicating with the coolant passage and arranged such that at least one part thereof is located at a lower position than a lowermost position of the coolant passage, and penetrates the unit fuel cells in the stacking direction.

Abstract: In this fuel cell, among a pair of separators in which an electrically conductive portion which is made from an electrically conducting material is surrounded by an insulating portion which is made from an insulating material, a cell side terminal is provided in the inner surface of the insulating portion of at least one said separator, and extends from its interior circumferential side to its outer perimeter side, and is able to electrically connect the interior and exterior of the cell. This cell side terminal is made from a metallic plate, and its inner circumferential side end portion contacts the membrane electrode assembly, while its outer perimeter side end portion extends to the outer perimeter side of the insulating portion. This outer perimeter side end portion can be connected to a measurement side terminal.

Abstract: A fuel cell stack includes a first end power generation unit and a first dummy unit, adjacent to a power generation unit provided at one end of a stack body in a stacking direction. The first end power generation unit includes a fourth separator having the same structure as a first separator of the power generation unit, and includes a fifth separator and a sixth separator having the same structure as a second separator and a third separator. In effect, common separators are used for the fifth separator and the sixth separator by changing a pin of a molding die or changing part of a seal die.

Abstract: A fuel cell according to the present invention includes a power generation unit. The power generation unit is formed by stacking a first metal separator, a first membrane electrode assembly, a second metal separator, a second membrane electrode assembly, and a third metal separator. The number of flow grooves in a first oxygen-containing gas flow field is different from the number of flow grooves in a second oxygen-containing gas flow field. The first oxygen-containing gas flow field and the second oxygen-containing gas flow field have the same length, and the flow grooves in the first oxygen-containing gas flow field and the flow grooves in the second oxygen-containing gas flow field have the same depth.

Abstract: Each of power generation units of a fuel cell according to the present invention is formed by stacking a first metal separator, a first membrane electrode assembly, a second metal separator, a second membrane electrode assembly, and a third metal separator together. The power generation unit has therein a first oxygen-containing gas flow field, a first fuel gas flow field, a second oxygen-containing gas flow field, and a second fuel gas flow field. The number of flow grooves in the first oxygen-containing gas flow field is different from that of flow grooves in the second oxygen-containing gas flow field, and the number of flow grooves in the first fuel gas flow field is different from that of flow grooves in the second fuel gas flow field.

Abstract: A first metal separator of one of adjacent power generation cells and a second metal separator of the other of the adjacent power generation cells are directly stacked together to form a coolant flow field. The first metal separator has a press line protruding toward the coolant flow field, between a fuel gas flow field and an inlet buffer. The second metal separator has a press line protruding toward the coolant flow field, between an oxygen-containing gas flow field and an inlet buffer. The press lines contact each other to limit flow of the coolant into a back surface buffer.

Abstract: Each of the fuel cell units making up a fuel cell stack includes a first separator, a second separator, and a third separator. A predetermined number of load receivers are provided integrally on outer ends of the first separator, the second separator, and the third separator. The load receivers of the second separator protrude toward the casing beyond the other load receivers. Resin clips are inserted into the load receivers, such that the first separator, the second separator, and the third separator are fixed together by the resin clips.

Abstract: Auxiliary seals are provided on a surface of a first metal separator, between load receivers and an oxygen-containing gas supply passage, a fuel gas supply passage, an oxygen-containing gas discharge passage, and a fuel gas discharge passage, in relatively wide areas. The cross sectional shape of the auxiliary seal is the same as those of a flow field seal and ring-like seals, and the auxiliary seals are formed independently from the flow field seal and the ring-like seals.

Abstract: A first metal separator of a fuel cell comprises a metal plate, and a first seal member is formed integrally on both surfaces of an outer edge of the metal plate. A first rib having a frame shape is provided around an oxygen-containing gas supply passage or the like of the metal plate. The first rib has a rib surface spaced away from an inner end surface of the metal plate around the oxygen-containing gas supply passage or the like, toward the oxygen-containing gas supply passage or the like.

Abstract: A terminal plate of a fuel cell stack includes an electron conductive area and a passage area. The electron conductive area is connected to an anode. The passage area includes passages for supplying an oxygen-containing gas, a fuel gas, and coolant to a membrane electrode assembly. The electron conductive area is made of composite of foamed metal and insulating resin. The passage area is made of the insulating resin. The electron conductive area and the passage area are combined together by injection molding, for example.

Abstract: This fuel cell stack includes: a coolant-supplying penetration hole and a coolant-discharging penetration hole each communicating with a coolant passage and each penetrates unit fuel cells in a stacking direction. A coolant-supplying penetration hole and a coolant-discharging penetration hole are arranged in a horizontal direction opposing with each other so as to sandwich a power generating region. The fuel cell stack further includes: an air draining penetration hole communicating with the coolant passage and arranged such that at least one part thereof is located at a higher position than an uppermost position of the coolant passage, and penetrates the unit fuel cells in the stacking direction; and a coolant draining penetration hole communicating with the coolant passage and arranged such that at least one part thereof is located at a lower position than a lowermost position of the coolant passage, and penetrates the unit fuel cells in the stacking direction.