The present invention relates to solid polymer electrolyte membranes (SPEMs) which include a co-processed mixture of a substrate polymer and an ion-conducting material membrane, or more preferably include a membrane comprising a polymer blend of a substrate polymer and an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells.
STATEMENT OF GOVERNMENT RIGHTS
 This invention was made with Government support under Contract No.65112-001-03 3D awarded by the Department of Energy. The Government has certain rights in this invention.