Patent ID: 7432008

Claim:
An electrochemical cell comprising: a membrane electrode assembly; a first reactant flow field plate for providing a first reactant flow field disposed on one side of the membrane electrode assembly; a first seal disposed between the first reactant flow field plate and the membrane electrode assembly for impeding leakage of process fluids of the electrochemical cell; a first gas diffusion layer disposed between the first reactant flow field plate and the membrane electrode assembly for diffusing reactant from the first reactant flow field to the membrane electrode assembly, the first gas diffusion layer including: a first side facing the first reactant flow field plate and a second side facing the membrane electrode assembly; a porous body for diffusing the reactant from the reactant flow field to the membrane electrode assembly; and an edge portion surrounding the porous body, the edge portion abutting the first seal and the membrane electrode assembly; wherein on the first side of the first gas diffusion layer a thickness of the edge portion is reduced in relation to the porous body to provide a step between the porous body and the edge portion, the step for engaging the first seal; and wherein the first seal has a thickness corresponding with a height of the step, such that the second side of the first gas diffusion layer provides a substantially flat surface for supporting the membrane electrode assembly to impede substantial distortion of the membrane electrode assembly at the first seal.