A seal structure is provided that follows fluctuations in a gap between a pair of fuel cell separators without generating a large tightening force. A pair of separators facing each other with an electrolyte membrane as a mating member interposed therebetween have beads which form a flow path for fluid between the beads and the electrolyte membrane in close contact with the electrolyte membrane. A seal which seals the pair of separators causes the beads 14 of the pair of these separators to overlap each other in a nested manner. A seal material having elasticity is provided between side walls of the respective beads which face each other. When the gap between the pair of separators fluctuates, the seal material deforms in a shearing direction.

a fuel battery includes a membrane-electrode assembly (MEA) in which a catalyst layer and a gas diffusion layer are stacked on each of opposite surfaces of a polymer electrolyte membrane; and separators between which the membrane-electrode assembly is interposed, wherein each of the separators includes a rib and a groove on a surface that is in contact with the gas diffusion layer, the rib and the groove forming a gas flow path through which a reaction gas to be used for power generation flows, when a thickness of the gas diffusion layer is defined as h, and a width of a portion of the rib that is in contact with the gas diffusion layer is defined as Rw, 0.29 Rw≤h≤0.55 Rw is satisfied, the gas diffusion layer includes conductive particles, conductive fibers, and a polymer resin, and average fiber length Fl and average fiber diameter Fd of the conductive fibers satisfy Fl<Rw/2 and Fd<h/100.

a fuel battery includes a membrane-electrode assembly (MEA) in which a catalyst layer and a gas diffusion layer are stacked on each of opposite surfaces of a polymer electrolyte membrane; and separators between which the membrane-electrode assembly is interposed, wherein each of the separators includes a rib and a groove on a surface that is in contact with the gas diffusion layer, the rib and the groove forming a gas flow path through which a reaction gas to be used for power generation flows, when a thickness of the gas diffusion layer is defined as h, and a width of a portion of the rib that is in contact with the gas diffusion layer is defined as Rw, 0.29 Rw≤h≤0.55 Rw is satisfied, the gas diffusion layer includes conductive particles, conductive fibers, and a polymer resin, and average fiber length Fl and average fiber diameter Fd of the conductive fibers satisfy Fl<Rw/2 and Fd<h/100.

A first outer peripheral seal in a first metal separator of a fuel cell stack includes a first peripheral metal bead. A first bypass stopper is provided in a space between a first end ridge and a first outer peripheral seal. The first bypass stopper prevents bypassing of an oxygen-containing gas by blocking part of the space. A gap is provided between the first bypass stopper and the first metal bead of a first outer peripheral seal. The gap separates the first bypass stopper from the first metal bead.

A first outer peripheral seal in a first metal separator of a fuel cell stack includes a first peripheral metal bead. A first bypass stopper is provided in a space between a first end ridge and a first outer peripheral seal. The first bypass stopper prevents bypassing of an oxygen-containing gas by blocking part of the space. A gap is provided between the first bypass stopper and the first metal bead of a first outer peripheral seal. The gap separates the first bypass stopper from the first metal bead.

A formed substrate assembly includes an air flow form plate, a fuel flow form plate, and an anode. The fuel flow form plate is positioned over the air flow form plate. The fuel flow form plate partially defines a plurality of first channels. The fuel flow form plate also defines a plurality of second channels. The plurality of second channels defines a plurality of apertures, where a portion of the apertures extend from the plurality of second channels to the plurality of first channels. The anode is positioned over the fuel flow form plate. The anode partially defines the plurality of first channels such that the fuel flow form plate and the anode define the plurality of first channels. The portion of the plurality of apertures is configured to channel a flow of fuel from the plurality of second channels to the plurality of first channels.

A formed substrate assembly includes an air flow form plate, a fuel flow form plate, and an anode. The fuel flow form plate is positioned over the air flow form plate. The fuel flow form plate partially defines a plurality of first channels. The fuel flow form plate also defines a plurality of second channels. The plurality of second channels defines a plurality of apertures, where a portion of the apertures extend from the plurality of second channels to the plurality of first channels. The anode is positioned over the fuel flow form plate. The anode partially defines the plurality of first channels such that the fuel flow form plate and the anode define the plurality of first channels. The portion of the plurality of apertures is configured to channel a flow of fuel from the plurality of second channels to the plurality of first channels.

A multiple perforation plate for fuel cell separators includes virtual flow path hole central lines spaced apart from each other at a constant interval in a length direction corresponding to a flow direction of reaction gas and formed in a width direction perpendicular to the flow direction of the reaction gas, a plurality of flow path holes formed at a constant interval on the flow path hole central lines in the width direction, and expansion parts formed at both sides of a middle point of each of the flow path holes in the width direction so as to have a greater width in the length direction than that of other points of each of the flow path holes.

A multiple perforation plate for fuel cell separators includes virtual flow path hole central lines spaced apart from each other at a constant interval in a length direction corresponding to a flow direction of reaction gas and formed in a width direction perpendicular to the flow direction of the reaction gas, a plurality of flow path holes formed at a constant interval on the flow path hole central lines in the width direction, and expansion parts formed at both sides of a middle point of each of the flow path holes in the width direction so as to have a greater width in the length direction than that of other points of each of the flow path holes.

A separator assembly for an air-cooled fuel cell includes: a cathode separator and an anode separator, each of which having a cooling surface bonded to each other to face each other. The separator assembly further includes a plurality of first gaskets having a ring shape configured to surround and seal a plurality of inlet manifolds and a plurality of outlet manifolds are disposed on a cooling surface of any one separator among the cooling surface of the cathode separator and the cooling surface of the anode separator. The plurality of first gaskets are configured to allow cooling air for cooling the cooling surface to flow between first gaskets adjacent to each other.