Abstract: A separator of a fuel cell stack, which has flat surfaces that face MEAs, includes a cathode-side plate, an anode-side plate and an intermediate plate. The intermediate plate has a plurality of oxidant gas supply channel openings that communicate with an oxidant gas supply manifold and oxidant gas supply holes of the cathode-side plate, and a plurality of oxidant gas exhaust channel openings that communicate with an oxidant gas exhaust manifold and oxidant gas exhaust holes of the anode-side plate. The width and spacing of the oxidant gas exhaust channel openings are set to be larger than those of the oxidant gas supply channel openings.

Abstract: A fuel cell (100) that generates power without discharging fuel gas includes: an electrolyte membrane (810); an anode (820) provided on one side of the electrolyte membrane; and a fuel-gas passage portion (840) provided on the outer side of the anode to form a fuel-gas supply passage through which fuel gas is supplied to the anode. The gas permeability of at least one of the electrolyte membrane and the anode in a thickness direction thereof varies from position to position in a direction the fuel-gas supply passage extends.

Abstract: A fuel cell system includes a fuel cell and a process executing unit. The fuel cell includes a plurality of flow channel-defining members and a plurality of membrane-electrode assemblies. The flow channel-defining member is combined with the membrane-electrode assembly and defines a flow channel for supplying a reactant gas to the membrane-electrode assembly. The process executing unit executes a process for increasing the amount of water held in each of the plurality of flow channel-defining members, so as to reduce variation in the amount of water among each of the plurality of flow channel-defining members. In this way, the variation in the amount of water can be reduced.

Abstract: This separator is equipped with a first plate 33 and a second plate 32. The first plate 33 has a first hole 3341 through which reaction gas flows. The second plate 32 is to be stacked with the first plate 33, and has a second hole 3241 through which the reaction gas flows. The second hole 3241 overlaps with the first hole 3341 at the first part 3231, and is in fluid communication with the first hole 3341. The second plate 32 has a partition part 323 that divides the part 3247 of the second part which does not overlap the first hole 3341 among the second holes 3241 into a plurality of flow path parts 56. The separator 30 is further equipped with an oscillating portion 325. The oscillating portion 325 is connected to the partition part 323. The oscillating portion 325 is arranged at a position such that part of the oscillating portion 325 overlaps with the first hole 3341 of the first plate 33. The oscillating portion 325 is provided so as to be shaken by the reaction gas that flows inside the first hole 3341.

Abstract: A separator of a fuel cell stack, which has flat surfaces that face MEAs, includes a cathode-side plate, an anode-side plate and an intermediate plate. The intermediate plate has a plurality of oxidant gas supply channel openings that communicate with an oxidant gas supply manifold and oxidant gas supply holes of the cathode-side plate, and a plurality of oxidant gas exhaust channel openings that communicate with an oxidant gas exhaust manifold and oxidant gas exhaust holes of the anode-side plate. The width and spacing of the oxidant gas exhaust channel openings are set to be larger than those of the oxidant gas supply channel openings.