Composite Nafion Membranes for Polymer Electrolyte and Direct Methanol Fuel Cells

Abstract In the last years, Direct Methanol Fuel Cells (DMFCs) are gaining momentum as electrochemical power generators for application in electric cars. The choice of such low polluting technology is preferred with respect to similar energy systems, like batteries or hydrogen fed fuel cells, because of higher simplicity of design and suitable energy density. Nevertheless, a few problems inherent to the use of this technology are connected with the present electrolyte membranes. The electrolytes commonly utilized in DMFC systems are based on perfluorosulfonic polymers (Nafion and Dow); these dehydrate when the fuel cell is working at high temperatures and allow a large methanol cross-over. Dehydration and cross-over are detrimental effects for a proper fuel cell operation.