Method of making a resilient seal for membrane electrode assembly (MEA) in an electrochemical fuel cell

An improved method of making a membrane electrode assembly ("MEA") for an electrochemical fuel cell is provided, which MEA comprises coextensive ion exchange membrane and electrode layers and a resilient fluid impermeable integral seal comprising a sealant material impregnated into the porous electrode layers in sealing regions of the MEA. The MEA is made from a multi-layer material by impregnating sealing regions with a flow processable sealant material, curing same, and cutting through said multi-layer material in said sealing regions. In preferred embodiments, the integral seal circumscribes the electrochemically active area of the MEA. The integral seal preferably also extends laterally beyond the edge of the MEA, thereby envelopping the peripheral region including the side edge of the MEA. An integral seal may also be provided around any openings, such as manifold openings, that are formed in the MEA. Preferably the sealant material is a flow processable elastomer applied to the MEA using an injection molding process prior to being cured. In preferred embodiments the seal has a plurality of spaced parallel raised ribs with cross ribs extending therebetween at spaced intervals. The raised ribs and cross ribs provide compartmentalized seals that provide improved protection against fluid leaks in a fuel cell assembly.