Abstract: A fuel cell includes a membrane electrode assembly and first and second metal plates sandwiching the membrane electrode assembly. The first metal plate has positioning ribs for positioning the outer region of the membrane electrode assembly. The first and second metal plates are positioned in alignment with each other by the first and second insulating bushings attached to first and second positioning holes of the first and second metal plates. Further, the first and second metal plates sandwiching the membrane electrode assembly are fastened together by a plurality of metal clip members.

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 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 and second metal plates. The coolant flow field is connected to inlet buffers and outlet buffers. Protrusions for limiting the flow of a coolant are provided at the inlet buffers and the outlet buffers on upper and lower opposite end positions of the coolant flow field.

Abstract: A fuel cell includes a membrane electrode assembly and first and second metal separators sandwiching the membrane electrode assembly. A first cell voltage terminal for detecting a voltage generated in the membrane electrode assembly is formed integrally with an outer region of the first metal separator. The first cell voltage terminal extends outwardly from the first metal separator. A first seal member covers the outer region of the first metal separator, and includes a first extension seal which covers the first cell voltage terminal to a position near a tip end of the first cell voltage terminal.

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 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 unit cell of a fuel cell stack has a first joint body sandwiched between a first separator and a second separator. The second separator has a first metal sheet having a region where grooves and ridges alternate with each other and a second metal sheet having a region where grooves and ridges alternate with each other, and a leaf spring interposed between the first and second metal sheets. The leaf spring is held against crests of the ridges of the first and second metal sheets. The grooves of the first metal sheet face the ridges of the second metal sheet across the leaf spring, and the ridges of the first metal sheet face the grooves of the second metal sheet across the leaf spring.

Abstract: A fuel cell is reduced in size and weight while the respective communication passages are reliably sealed by the respective sealing members between separators and an electrode assembly. Separators of a fuel cell is provided with communication holes for a reaction gas and cooling medium provided in the outer side of gas sealing members, and with a communication passage that detours around the gas sealing members in the thickness direction of the separators and connects gas communication passages with the reaction gas communication hole. A cooling surface sealing member that seals off the cooling medium communication passage from the reaction gas communication hole is located at a position that is shifted from the communicating passage towards the communication hole side.

Abstract: A cell assembly includes a first unit cell and a second unit cell stacked 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, oxidizing gas passages and fuel gas passages are provided in parallel along the first and second unit cells.

Abstract: A cell stack, in which a plurality of cell units are stacked, is accommodated in a case which has a bottom plate, a first side plate, a second side plate, and a ceiling plate. End plates are arranged at both open ends of the case. The case and the end plates are connected to one another by a hinge mechanism in which pins are engaged into through-holes of tab sections to provide a fuel cell stack.

Abstract: A fuel cell stack is disclosed, so as to prevent the corrosion of the power output terminal plate due to coolant and the occurrence of electric short circuits through the coolant, and to improve the flexibility of selection of the coolant. The fuel cell stack has unit fuel cells, each comprising an anode, a cathode, and an electrolyte which is placed between the anode and the cathode, wherein the unit fuel cells are stacked via separators. A pair of power output terminal plates are provided, one attached to each end face of the stacked unit fuel cells. A coolant supply and drainage passage and a gas supply and exhaust passage are formed through the stacked unit fuel cells and the power output terminal plates in the stacking direction, and the edge of each passage through the power output terminal plates is covered with a grommet having an insulating capability.

Abstract: A fuel cell is provided that is reduced in both size and weight while securing a sealed state of respective flow passages by respective sealing members between separators and an electrode assembly. In this fuel cell, there are provided in each of the separators communication ports for reaction gases and cooling medium that are provided outward from gas sealing members, and communication paths that detour around the gas sealing members in the thickness direction of the separators and connect the reaction gas communication ports with gas flow passages. A cooling surface sealing member that seals off the cooling medium flow passage from the reaction gas communication ports is placed at a position shifted from the communication paths towards the communication holes.

Abstract: A fuel cell that is small and light has separators having communication ports for reaction gases and cooling medium that are provided on an outer side of gas sealing members so as to penetrate each of the separators, and communication paths that detour around the gas sealing members in the thickness direction of the separators and connect the reaction gas communication ports with reaction gas flow passages. Furthermore, support members are provided to support the portions of the separators at which the gas sealing members and the cooling surface sealing member are disposed so as to be offset with respect to each other as viewed in the stacking direction.

Abstract: There is provided a fuel cell that is reduced in both size and weight while securing a sealed state of respective communication paths by respective sealing members between separators and an electrode assembly. In this fuel cell there are provided in each one of separators communication ports for reaction gases and cooling medium that are provided on an outer side of gas sealing members, and communication paths that detour around the gas sealing members in the thickness direction of the separators and connect the reaction gas communication ports with gas communication paths. A cooling surface sealing member that seals off the cooling medium communication path from the reaction gas communication holes is placed at a position shifted from the communication paths towards the communication holes. A convex portion is provided between the reaction gas communication path and the communications ports of one separator, while a concave portion that receives the convex portion is provided in the other separator.

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.

Abstract: A fuel cell includes a plurality of metal clip members for holding outer regions of first and second metal separators at a plurality of positions. Each of the metal clip member includes a side plate and first and second holding portions. The side plate is curved at opposite ends, and the first and second holding portions are extending from the opposite ends of the side plate. The first and second holding portions generates a predetermined elastic force for holding the first and second metal separators. The outer ends of the first and second metal separators are covered by insulating sections, and the insulating sections are held between the first and second holding portions so that the entire unit cell is tightened by the predetermined elastic force.

Abstract: A cell assembly (10) includes a first unit cell (14) and a second unit cell (16) which are stacked to each other. The first unit cell (14) has a first unified body (18), and the second unit cell (16) has a second unified body (20). A plurality of oxidizing gas passages (46, 58) and a plurality of fuel gas passages (56, 52) are provided in the cell assembly (10). The oxidizing gas passages (46)in the first unit cell (14) and the oxidizing gas passages (58) in the second unit cell (16) are communicated in series to each other. The fuel gas passages (56) in the first unit cell (14) and the fuel gas passages (52) in the second unit cell (16) are communicated in series to 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 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.