Toyota Jidosha Kabushiki Kaisha, EI Du Pont De Nemours and Company and | Date: 2011-12-20
This invention relates to solid polymer electrolyte materials for use in one or more electrode of a fuel cell. The solid polymer electrolyte materials comprise one or more ionomer which comprises polymerized units of monomers A and monomers B, wherein monomers A are perfluoro dioxole or perfluoro dioxolane monomers, and the monomers B are functionalized perfluoro olefins having fluoroalkyl sulfonyl, fluoroalkyl sulfonate or fluoroalkyl sulfonic acid pendant groups, CF_(2)CF(O)[CF_(2)]_(n)SO_(2)X. The ionomer of the solid polymer electrolyte material has a number average molecular weight, Mn, of greater than 140,000. Specifically, the ionomers of the invention may find use in the catalyst layer of an electrode because the high molecular weight ionomers mitigate the formation of cracks in the catalyst layer.