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 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: An oxygen-containing gas flow field for supplying an oxygen-containing gas from an oxygen-containing gas supply passage to an oxygen-containing gas discharge passage is formed on a first metal plate. The oxygen-containing gas flow field includes oxygen-containing gas flow grooves as serpentine flow grooves having two turn regions T1, T2. The oxygen-containing gas flow grooves have substantially the same length. The oxygen-containing gas flow grooves are connected to an inlet buffer and an outlet buffer at opposite ends. The inlet buffer and the outlet buffer have a substantially triangular shape, and are substantially symmetrical with each other.

Abstract: A power generation cell includes a membrane electrode assembly and first and second metal separators sandwiching the membrane electrode assembly. Ridge members are formed integrally on the second metal separator, and these ridge members contact a first seal member of the first metal separator under pressure to form an inlet connection channel and an outlet connection channel. The coolant supply passage and the coolant flow field are connected through the inlet connection channel and the coolant discharge passage and the coolant flow field are connected through the outlet connection channel.

Abstract: A fuel cell includes a membrane electrode assembly, and first and second separators. A first insulating bushing is attached to a first positioning hole of a first separator, and a second insulating bushing is attached to a second positioning hole of the second separator. An inner wall of the first insulating bushing is fitted to an outer wall of the second insulating bushing for positioning the first and second separators such that the first and second separators are insulated from each other.

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: A coolant flow field is formed on a surface of a second metal separator. Further, a rubber bridge dividing the coolant flow field and a coolant supply passage is formed on the surface. The rubber bridge includes a plurality of channels connecting the coolant flow field and the coolant supply passage, a plurality of grooves between the channels, and a partition closing the grooves to prevent the flow of a coolant in the respective grooves.

Abstract: A fuel cell includes a plurality of fuel cell units, each fuel cell unit including an electrode assembly formed by disposing electrodes on both sides of an electrolyte, a pair of separators that sandwich the electrode assembly, and gas sealing members that are disposed at an outer peripheral portion of the electrode assembly, and that seal respective reaction gas flow passages that are formed between each separator and the electrode assembly. In one of the separators of each of the fuel cell units, a through path is formed that penetrates the separator in the thickness direction thereof, and the through path formed in one of the separators, of one of the fuel cell units and the through path formed in one of the separators of adjacent one of the fuel cell units are offset with each other as viewed in the thickness direction of the separators.

Abstract: Flow guides forming an inlet channel are formed on a surface of a metal separator of a fuel cell. The flow guides overlap a section of an outer seal provided on the other surface of the metal separator. When a load is applied to the flow guides and the overlapping section in a stacking direction of the fuel cell, the flow guides and the overlapping section are deformed substantially equally in the stacking direction to the same extent. The line pressure of the flow guides and the line pressure of the overlapping section are substantially the same. The seal length L1 of the flow guides and the seal length L2 of the overlapping section are substantially the same.

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 power generation cell includes a membrane electrode assembly, with an anode side metal separator and a cathode side metal separator sandwiching the membrane electrode assembly. Flow field walls are provided within the coolant flow field for preventing coolant from flowing into an area corresponding to an oxygen-containing gas inlet buffer, while allowing the coolant to flow into an area corresponding to an oxygen-containing gas outlet buffer. Likewise, flow field walls contact each other for preventing the coolant from flowing into an area corresponding to a fuel gas inlet buffer, while allowing the fuel gas to flow into an area corresponding to a fuel gas outlet buffer.

Abstract: A cell assembly is formed by stacking a first unit cell and a second unit cell to each other. The first unit cell includes a first unified body, and the second unit cell includes a second unified body. In the cell assembly, the first and second unit cells have structures different from each other.

Abstract: In a power generation unit of a fuel cell stack, bosses of a first metal separator and bosses of a second metal separator are provided to sandwich a first membrane electrode assembly at first sandwiching positions on both sides of the first membrane electrode assembly, oppositely to each other in a stacking direction. Bosses of a second metal separator and bosses of a third metal separator are provided to sandwich a second membrane electrode assembly at second sandwiching positions on both sides of the second membrane electrode assembly, oppositely to each other in the stacking direction. Bosses of the first metal separator and bosses of the third metal separator protrude toward a coolant flow field, and contact each other at positions offset from the first and second sandwiching positions.

Abstract: An oxygen-containing gas flow field for supplying an oxygen-containing gas from an oxygen-containing gas supply passage to an oxygen-containing gas discharge passage is formed on a first metal plate. The oxygen-containing gas flow field includes oxygen-containing gas flow grooves as serpentine flow grooves having two turn regions T1, T2. The oxygen-containing gas flow grooves have substantially the same length. The oxygen-containing gas flow grooves are connected to an inlet buffer and an outlet buffer at opposite ends. The inlet buffer and the outlet buffer have a substantially triangular shape, and are substantially symmetrical with each other.

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: Flow guides forming an inlet channel are formed on a surface of a metal separator of a fuel cell. The flow guides overlap a section of an outer seal provided on the other surface of the metal separator. When a load is applied to the flow guides and the overlapping section in a stacking direction of the fuel cell, the flow guides and the overlapping section are deformed substantially equally in the stacking direction to the same extent. The line pressure of the flow guides and the line pressure of the overlapping section are substantially the same. The seal length L1 of the flow guides and the seal length L2 of the overlapping section are substantially the same.

Abstract: A fuel cell includes a plurality of fuel cell units. Each fuel cell unit includes an electrode assembly having electrodes and an electrolyte, a pair of separators, and gas sealing members. At least two of the fuel cell units include at least two electrode assemblies and at least three separators. In each of the separators, reaction gas communication ports are provided. In one of the separators of one of the stacked fuel cell units that is located at the end in a direction of stacking, through paths are formed. In one of the separators of one of the stacked fuel cell units that is located at the other end in the direction of stacking, reaction gas communication paths are formed. Both the through paths and the reaction gas communication paths are formed in all separators that are located between two fuel cell units that are located at the ends.

Abstract: An oxygen-containing gas flow field for supplying an oxygen-containing gas from an oxygen-containing gas supply passage to an oxygen-containing gas discharge passage is formed on a first metal plate. The oxygen-containing gas flow field includes oxygen-containing gas flow grooves as serpentine flow grooves having two turn regions T1, T2. The oxygen-containing gas flow grooves have substantially the same length. The oxygen-containing gas flow grooves are connected to an inlet buffer and an outlet buffer at opposite ends. The inlet buffer and the outlet buffer have a substantially triangular shape, and are substantially symmetrical with each other.

Abstract: A fuel cell includes a membrane electrode assembly and first and second metal separators for sandwiching the membrane electrode assembly. In the membrane electrode assembly, a surface area of a gas diffusion layer is larger than a surface area of a gas diffusion layer. A seal member is provided at a position corresponding to an outer marginal region of the gas diffusion layer. The seal member includes a main seal inserted between a solid polymer electrolyte membrane and the first metal separator, and an a flow field wall inserted between the gas diffusion layer and the first metal separator for defining a part of an oxygen-containing gas flow field.

Abstract: A first separator has an outlet side first connection channel connecting a first fuel gas flow field and a fuel gas discharge passage, and a second separator includes an outlet side second connection channel connecting a second fuel gas flow field and the fuel gas discharge passage. The outlet side first connection channel and the outlet side second connection channel include outer passages and outer passages arranged in the same plane formed by facing the first separator and the second separator. The outer passages and the outer passages are formed alternately and independently in the same plane.

Abstract: A fuel cell includes a membrane electrode assembly, and first and second separators. A first insulating bushing is attached to a first positioning hole of a first separator, and a second insulating bushing is attached to a second positioning hole of the second separator. An inner wall of the first insulating bushing is fitted to an outer wall of the second insulating bushing for positioning the first and second separators such that the first and second separators are insulated from each other.