FUEL CELL STACK

A method for use in manufacturing a fuel cell stack includes assembling a membrane electrode assembly to have a membrane between a first gas diffusion layer and a second gas diffusion layer. A bypass blocker is located at a space between a first gas diffusion layer of the membrane electrode assembly and a seal. The blocker is deformed on the seal and deformation is avoided of the blocker at the space such that the blocker inhibits a bypass flow of a reactant through the space between the gas diffusion layer and the seal in a direction of flow of the reactant during operation of the fuel cell. The membrane electrode assembly is located between a first fluid flow plate and a second fluid flow plate.