Abstract: A power generation cell of a fuel cell includes a membrane electrode assembly, and a first separator and a second separator sandwiching the membrane electrode assembly. First supply holes, first discharge holes, second supply holes and second discharge holes extend through the membrane electrode assembly in a stacking direction. The first supply holes connect a fuel gas supply passage and a fuel gas flow field. The first discharge holes connect a fuel gas discharge passage and the fuel gas flow field. The second supply holes connect an oxygen-containing gas supply passage and an oxygen-containing gas flow field. The second discharge holes connect an oxygen-containing gas discharge passage and the oxygen-containing gas flow field.

Abstract: A fuel cell stack includes a plurality of power generation cells stacked in a direction of gravity. In a cathode side separator of the power generation cell, an oxygen-containing gas discharge passage is connected to an oxygen-containing gas flow field, and a water guide member is provided for the oxygen-containing gas discharge passage for allowing condensed water to be directly dropped in the direction of gravity along the oxygen-containing gas discharge passage. The water guide member is a plate member protruding into the oxygen-containing gas discharge passage and inclined toward the direction of gravity.

Abstract: A seal member is formed integrally on surfaces of a metal separator of a fuel cell. The seal member includes an outer seal and an inner seal provided on a surface of the metal separator. A plurality of closure seals are formed integrally with an inner edge of the inner seal. The closure seals close a space between the inner seal and a protrusion forming a fuel gas flow field.

Abstract: A first separator to which a resin film is joined beforehand is set in a cavity formed between a lower die and an upper die of an injection molding machine. At the time of die locking by moving the upper die toward the lower die, in the case where the total thickness of the resin film and the first separator is larger than a predetermined dimension, the resin film is pressed by the lower die or the upper die, and thus, the resin film is deformed by compression within its elastic deformation range.

Abstract: A separator comprises a first and second metal plates laid over each other. A cooling medium flow passage is integrally provided between the first and second metal plates. The cooling medium flow passage has inlet buffer portions communicating with a cooling medium inlet communication hole, outlet buffer portions communicating with a cooling medium outlet communication hole, and linear flow passage grooves linearly extending in the direction of arrow B and that of arrow C.

Abstract: A fuel cell is formed by sandwiching a membrane electrode assembly between a first separator and a second separator. A fuel gas flow field is formed in the second separator. An inlet buffer is connected to the inlet of the fuel gas flow field, and an outlet buffer is connected to an outlet of the fuel gas flow field. The inlet buffer is deeper than the outlet buffer. Therefore, the pressure loss in the inlet buffer is smaller than the pressure loss in the outlet buffer.

Abstract: A fuel cell system includes an oxidant gas supply apparatus and a fuel gas supplier. The oxidant gas supply apparatus includes first and second open/close valves disposed respectively in oxidant gas supply and discharge lines, and an oxidant gas flow field having a first volume and formed between the first and second open/close valves. The fuel gas supplier includes third and fourth open/close valves disposed respectively in fuel gas supply and discharge lines, and a fuel gas flow field having a second volume and formed between the third and fourth open/close valves. A ratio of the first volume to the second volume is determined such that substantially all oxygen in the oxidant gas remaining in the oxidant gas flow field is consumed by reaction with the fuel gas remaining in the fuel gas flow field when the oxidant gas flow field and the fuel gas flow field are closed.

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: 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 fuel cell includes a membrane electrode assembly and separators sandwiching the membrane electrode assembly. Each of the separators includes first and second metal plates. When the fist and second metal plates are stacked together, an inlet buffer and an outlet buffer are overlapped with each other in the stacking direction. A plurality of bosses in the inlet buffer and a plurality of bosses in the outlet buffer are not overlapped with each other.

Abstract: A fuel cell includes a membrane electrode assembly and first and second metal separators. The first metal separator has first outer protrusions provided outside an oxygen-containing gas flow field. The second metal separator has second outer protrusions provided outside a fuel gas flow field. The first and second protrusions sandwich outer edges of electrode catalyst layers.

Abstract: A fuel cell stack comprising a second metal separator set to have an external dimension larger than a first metal separators, wherein the second metal separator comprises, formed integrally, a first seal member in contact with the peripheral edge of a first electrolyte membrane/electrode structure, a second seal member in contact with the peripheral edge of the first metal separator, and a third seal member in contact with the peripheral edge of an adjoining fourth metal separator. Since the first seal member, the second seal member and the third seal member are integrally formed on one surface of the second separator or one surface of the first separator, a seal-forming step can be carried out at one effort, simply and economically. In addition, use of a triple seal structure containing the first through the third seal members can favorably improve the sealing feature of reaction gas and minimize reaction gas leakage.

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: A fuel cell according to the present invention includes a power generation cell. The power generation cell is formed by sandwiching a membrane electrode assembly between a first metal separator and a second metal separator. An oxygen-containing gas flow field is formed on one surface of the first metal separator, and a coolant flow field is formed on the other surface of the first metal separator. The first metal separator includes a corrugated metal plate. A resin frame member is provided on one surface of the metal plate, and a rubber seal is provided on the other surface of the metal plate. An oxygen-containing gas supply passage, an oxygen-containing gas discharge passage, a coolant supply passage, a coolant discharge passage, a fuel gas supply passage, and a fuel gas discharge passage extend through the metal plate, the resin frame member, and the rubber seal.

Abstract: A unit cell of a fuel cell is formed by stacking a membrane electrode assembly between a first metal separator and a second metal separator in a stacking direction. A frame is provided in an outer end of the membrane electrode assembly. A seal member is formed on the frame. The seal member includes a first seal as a fuel gas seal, a second seal as a coolant seal, and a third seal as an oxygen-containing gas seal. The first seal, the second seal, and the third seal are offset from each other in the stacking direction.

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: A fuel cell stack (10) includes a first sub-stack (12), a second sub-stack (14), and a third sub-stack (16) disposed in the flow direction of an oxidizing gas. An intermediate plate (18a) is interposed between the first and second sub-stacks (12, 14), and an intermediate plate (18b) is interposed between the second and third sub-stacks (14, 16). In this fuel stack (10), the flow of an oxidizing gas is set such that the oxidizing gas flows in series in the direction from the first sub-stack (12) to the third sub-stack (16). Between the sub-stacks additional oxidizing gas supplies (70,74) are provided through which oxidizing gas of lower humidity than the humidity of the oxidizing gas entering the first sub-stack is supplied. This arrangement allows an efficient management of the humidity water content of the oxidizing gas with sufficient moisturizing of the solid polymer membrane whilst avoiding excessive condensation of water vapour within the stack.