Membrane electrode assembly for an electrochemical fuel cell

摘要

An improved membrane electrode assembly ("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 the sealing regions. The integral seal preferably circumscribes the electrochemically active area of the MEA. The integral seal preferably also extends laterally beyond the edge of the MEA. An integral seal may also be provided around any openings, such as external manifold openings formed outside the MEA. Preferably, the uncured sealant material is a flow processable elastomer applied using an injection molding process. 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.