Sulfonated polyphosphazenes for proton-exchange membrane fuel cells
AssigneeThe Administrators of the Tulane Educational Fund
InventorsPeter N. Pintauro, Hao Tang
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Abstract
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 poly[bis(3-methylphenoxy)phosphazene] as the base polymer, with sulfonated ion-exchange groups, for direct liquid-feed methanol fuel cells.
Claims29
A high proton conductance, solid polymer electrolyte membrane for use in a proton exchange membrane fuel cell, said membrane comprising:
- a sulfonated phosphazene polymer, the sulfonated phosphazene polymer being chemically or physically cross-linked, wherein chemical cross-links are formed between the main chains of the sulfonated phosphazene polymer, wherein the sulfonated phosphazene polymer has an ion-exchange capacity between about 0.8 and 1.9 mmole per gram of dry polymer, and wherein the cross-links are formed in a dry polymer film by means of ultraviolet light and a photo-initiator.
The membrane according to claim to 1, wherein the photo-initiator is benzophenone.
A high proton conductance, solid polymer electrolyte membrane for use in a proton exchange membrane fuel cell, said membrane comprising:
- a sulfonated phosphazene polymer, the sulfonated phosphazene polymer being chemically or physically cross-linked, wherein physical cross-links are created by blending the sulfonated phosphazene polymer with at least one substantially non-sulfonated polymer.
A hydrogen or direct liquid-feed methanol fuel cell, comprising:
- an anode, a cathode, and a sulfonated phosphazene polymer electrolyte membrane operating in a hydrated state, wherein the polymer electrolyte membrane exhibits low fuel permeability.
A hydrogen or direct liquid-feed methanol fuel cell, comprising:
- an anode, a cathode, and a sulfonated phosphazene polymer electrolyte membrane operating in a hydrated state, wherein the sulfonated phosphazene polymer is chemically or physically cross-linked.
An tonically conductive membrane, said membrane comprising:
- a phosphazene polymer containing acidic functional groups, wherein the polyphosphazene polymer is blended with one or more polymers having substantially no acidic functional groups, and wherein the concentration of the acidic functional groups is between about 0.8 mmole per gram of dry polymer and about 1.9 mmole per gram of dry polymer.
Dependencies are inferred from the claim text.