Sulfonated polyphosphazenes for proton-exchange membrane fuel cells

摘要

The subject matter of this invention deals with sulfonated polyphosphazene-based cation-exchange membranes for proton-exchange membrane fuel cells where the polyphosphazene is crosslinked, non-crosslinked, suitably blended with one or more additional polymers, and/or impregnated into the void volume of an inert microporous membrane support and where the membranes operate in a hydrated state that is characterized by a high proton conductance and low water and methanol permeation rates. In particular, the invention relates to the use of polybis(3-methylphenoxy)phosphazene as the base polymer, with sulfonated ion-exchange groups, for direct liquid-feed methanol fuel cells.