Abstract: A fuel cell includes: a membrane electrode gas diffusion layer assembly in which a membrane electrode assembly is sandwiched by a pair of gas diffusion layers; an insulating member formed into a frame shape, and being in contact with an outer peripheral portion of the membrane electrode gas diffusion layer assembly; and first and second separators sandwiching the membrane electrode gas diffusion layer assembly and the insulating member.

Abstract: Stacked unit cells 100 of a fuel cell each comprise a membrane electrode assembly 10, a pair of gas separators 40 and 50, and a first sealing portion 26 provided between the pair of gas separators. The fuel cell further comprises a second sealing portion provided between adjacent ones of the unit cells, a first manifold in which reaction gas flows, and a second manifold in which a coolant flows. One of the first sealing portion and the second sealing portion is an adhesive sealing portion, and another one of the first sealing portion and the second sealing portion is formed of a gasket. The adhesive sealing portion and the gasket are provided along the outer circumference of the manifold, in the fuel cell as viewed in a stacking direction. The gasket and the adhesive sealing portion are arranged in this order from a side closer to the manifold.

Abstract: A fuel cell includes: a membrane electrode gas diffusion layer assembly in which a membrane electrode assembly is sandwiched by a pair of gas diffusion layers; an insulating member formed into a frame shape, and being in contact with an outer peripheral portion of the membrane electrode gas diffusion layer assembly; and first and second separators sandwiching the membrane electrode gas diffusion layer assembly and the insulating member.

Abstract: A fuel cell includes a power generating body including a membrane electrode assembly, a resin frame placed around the power generating body, and a pair of separators laminated on the resin frame so as to sandwich the power generating body and the resin frame. The resin frame has a resin-frame-side manifold in which reaction gas flows in a direction passing through the resin frame, an opening that holds the power generating body, and a gas introduction channel formed through the resin frame between the resin-frame-side manifold and the opening. Each separator has a separator-side manifold through which the reaction gas flows, and which is provided at a position corresponding to the resin-frame-side manifold in a lamination direction, and the gas introduction channel has a gas introduction part that extends into the separator-side manifold, when viewed in the lamination direction.

Abstract: A fuel-cell unit cell comprises an MEGA plate with a resin frame, and two separators. There is formed a gas manifold hole in an outer edge portion of the resin frame. There is provided a gas-flow-path forming portion with a recessed-and-protruded shape on the first surface of the resin frame for forming gas flow paths between the gas manifold hole and the first surface of the MEGA. There is also formed a fusion-bonding portion for surrounding a periphery of the gas manifold hole to cut off gas circulation between the gas manifold hole and the second surface of the MEGA and for bonding the resin frame and the second separator with each other, on the second surface of the resin frame so as to pass across a backside of the gas-flow-path forming portion. The fusion-bonding portion is formed from a first resin, and the gas-flow-path forming portion is formed from a second resin higher in melting point than the first resin.

Abstract: A fuel-cell unit cell comprises an MEGA plate with a resin frame, and two separators. There is formed a gas manifold hole in an outer edge portion of the resin frame. There is provided a gas-flow-path forming portion with a recessed-and-protruded shape on the first surface of the resin frame for forming gas flow paths between the gas manifold hole and the first surface of the MEGA. There is also formed a fusion-bonding portion for surrounding a periphery of the gas manifold hole to cut off gas circulation between the gas manifold hole and the second surface of the MEGA and for bonding the resin frame and the second separator with each other, on the second surface of the resin frame so as to pass across a backside of the gas-flow-path forming portion. The fusion-bonding portion is formed from a first resin, and the gas-flow-path forming portion is formed from a second resin higher in melting point than the first resin.

Abstract: A fuel-cell unit cell comprises an MEGA plate with a resin frame, and two separators. There is formed a gas manifold hole in an outer edge portion of the resin frame. There is provided a gas-flow-path forming portion with a recessed-and-protruded shape on the first surface of the resin frame for forming gas flow paths between the gas manifold hole and the first surface of the MEGA. There is also formed a fusion-bonding portion for surrounding a periphery of the gas manifold hole to cut off gas circulation between the gas manifold hole and the second surface of the MEGA and for bonding the resin frame and the second separator with each other, on the second surface of the resin frame so as to pass across a backside of the gas-flow-path forming portion. The fusion-bonding portion is formed from a first resin, and the gas-flow-path forming portion is formed from a second resin higher in melting point than the first resin.

Abstract: A relation of X×?T×CTEt<L×t is satisfied, where X represents a distance between a circumferentially innermost position of a bonded portion of a resin frame bonded to first projections of separators and a circumferentially inner end of the resin frame; L represents a distance between the circumferentially inner end of the resin frame and a circumferentially outermost position of a held portion of a membrane electrode gas-diffusion-layer assembly that is interposed and held between second projections of the separators: ?T represents a temperature difference from a low temperature T1 of ?40° C. to a high temperature T2 of 100° C. CTEf represents an average coefficient of linear expansion of the resin frame within a range of the low temperature T1 to the high temperature T2; t represents a breaking elongation of the electrolyte membrane at the low temperature T1; and the distances X, L represents dimensions at the high temperature T2.

Abstract: Stacked unit cells 100 of a fuel cell each comprise a membrane electrode assembly 10, a pair of gas separators 40 and 50, and a first sealing portion 26 provided between the pair of gas separators. The fuel cell further comprises a second sealing potion provided between adjacent ones of the unit cells, a first manifold in which reaction gas flows, and a second manifold in which a coolant flows. One of the first sealing portion and the second sealing portion is an adhesive sealing portion, and another one of the first sealing portion and the second sealing portion is formed of a gasket. The adhesive sealing portion and the gasket are provided along the outer circumference of the manifold, in the fuel cell as viewed in a stacking direction. The gasket and the adhesive sealing portion are arranged in this order from a side closer to the manifold.

Abstract: A fuel cell includes a power generating body including a membrane electrode assembly, a resin frame placed around the power generating body, and a pair of separators laminated on the resin frame so as to sandwich the power generating body and the resin frame. The resin frame has a resin-frame-side manifold in which reaction gas flows in a direction passing through the resin frame, an opening that holds the power generating body, and a gas introduction channel formed through the resin frame between the resin-frame-side manifold and the opening. Each separator has a separator-side manifold through which the reaction gas flows, and which is provided at a position corresponding to the resin-frame-side manifold in a lamination direction, and the gas introduction channel has a gas introduction part that extends into the separator-side manifold, when viewed in the lamination direction.

Abstract: A fuel-cell unit cell comprises an MEGA plate with a resin frame, and two separators. There is formed a gas manifold hole in an outer edge portion of the resin frame. There is provided a gas-flow-path forming portion with a recessed-and-protruded shape on the first surface of the resin frame for forming gas flow paths between the gas manifold hole and the first surface of the MEGA. There is also formed a fusion-bonding portion for surrounding a periphery of the gas manifold hole to cut off gas circulation between the gas manifold hole and the second surface of the MEGA and for bonding the resin frame and the second separator with each other, on the second surface of the resin frame so as to pass across a backside of the gas-flow-path forming portion. The fusion-bonding portion is formed from a first resin, and the gas-flow-path forming portion is formed from a second resin higher in melting point than the first resin.

Abstract: A relation of X×?T×CTEt<L×t is satisfied, where X represents a distance between a circumferentially innermost position of a bonded portion of a resin frame bonded to first projections of separators and a circumferentially inner end of the resin frame; L represents a distance between the circumferentially inner end of the resin frame and a circumferentially outermost position of a held portion of a membrane electrode gas-diffusion-layer assembly that is interposed and held between second projections of the separators: ?T represents a temperature difference from a low temperature T1 of ?40° C. to a high temperature T2 of 100° C. CTEf represents an average coefficient of linear expansion of the resin frame within a range of the low temperature T1 to the high temperature T2; t represents a breaking elongation of the electrolyte membrane at the low temperature T1; and the distances X, L represents dimensions at the high temperature T2.

Abstract: A proton conductor includes a main constituent element. A part of the main constituent element is substituted by a transition metal. Valence of the transition metal is variable between valence of the main constituent element and valence lower than the valence of the main constituent element.