Patent ID: 8710108

Claim:
A method of making a proton conducting polymer electrolyte comprising a proton conducting ionomer and a polymetaloxane copolymer additive, the method comprising: (a) copolymerizing a plurality of metal oxide monomers with cross-linking functional groups and a plurality of metal oxide monomers with other functional groups, in random or block sequence to form the metaloxane copolymer exhibiting the cross-linking functional groups and the other functional groups, wherein: the metal oxide monomers with the cross-linking functional groups comprise: a first metal bonded to at least two oxygen atoms and selected from the group consisting of Si, Ti, Zr, Ce, Ta, and Cr; and the cross-linking functional groups bonded to the first metal and comprising a functional end group containing nitrogen or oxygen and characterized by a chemical structure selected from the group consisting of —NH 2 , ═NH, -(aliphatic)-OH, -(aryl)-OH, wherein R is a hydrocarbon group; and wherein the metal oxide monomers with the other functional groups comprise: a second metal bonded to at least two oxygen atoms and selected from the group consisting of Si, Ti, Zr, Ce, Ta, and Cr; and the other functional groups bonded to the second metal are selected from the group consisting of: i) proton carrier functional groups comprising a functional end group selected from the group consisting of —PO 3 H 2 , —COOH, —SO 3 H, and —SO 2 NHSO 2 CF 3 , ii) metal chelating functional groups comprising a functional end group selected from the group consisting of phosphonic acid, bipyridine, phenanthroline, and derivatives thereof, and iii) free radical scavenger functional groups comprising a functional end group selected from the group consisting of aminophenyl, hydroxyphenyl and derivatives thereof, (b) mixing an amount of (i) the polymetaloxane copolymer following copolymerization, or (ii) a mixture of the metal oxide monomers prior to copolymerization, with an amount of the proton conducting ionomer; and (c) heating the mixture such that a polymetaloxane copolymer is formed and the polymetaloxane copolymer and the proton conducting ionomer are covalently bonded or acid-base complexed together at the cross-linking functional groups of the polymetaloxane copolymer.