Gas diffusion backing for fuel cells

摘要

A gas diffusion backing for fuel cells wherein a porous carbonaceous paper or fabric, impregnated with a first fluorinated polymer, bears a microporous coating of a second fluorinated polymer admixed with carbon particles. Also, a process for making the composite wherein the fluorinated polymers are coalesced by heating above their glass transition temperature or melting point is described. A membrane electrode assembly prepared using these gas diffusion backing and a fuel are also provided.