Patent ID: 8785072

Claim:
A fuel cell stack comprising: a plurality of membrane-electrode assemblies; first and second end plates respectively positioned outside outermost ones of the membrane-electrode assembles; and a plurality of separators respectively positioned between the membrane-electrode assemblies and between the outermost ones of the membrane-electrode assemblies and the first and second end plates, for supplying at least one of a fuel or an oxidizing agent to the membrane-electrode assemblies, wherein the first end plate includes an oxidizing agent inlet, an oxidizing agent outlet, and a moisture supplying flow path connecting the oxidizing agent inlet and the oxidizing agent outlet, the moisture supplying flow path having at least one portion formed inside the first end plate and having a cross-section spaced apart from each outer surface of the first end plate, and wherein the moisture supplying flow path includes a first end portion adjacent to the oxidizing agent outlet and a second end portion adjacent to the oxidizing agent inlet, the first end portion being larger than the second end portion and being a different distance away from a surface of the first end plate facing away from the second end plate than the second end portion.