New Proton Exchange Membranes for Fuel Cells

We propose to develop a new class of proton exchange membranes (PEM) based on polyphenylene polymers. These new PEM's are designed to overcome fuel crossover problems encountered with conventional sulfonated fluoropolymers. Recently, Maxdem has conducted preliminary studies of polyphenylene PEM's and demonstrated the outstanding properties of these materials for proton conductivity. The proton conductivities of some of these polymer materials are much higher than Dupont's Nafionr membranes, even at high temperature (>100¿C). Films with methanol absorption comparable to the commercial products showed better performance in operating direct methanol fuel cells (DMFC). A new approach is proposed in this proposal to minimize the solvent crossover while maintaining high proton conductivity. Further investigation based on the preliminary results is expected to provide PEM's for practical fuel cell applications with unmatched performance and at lower costs than current commercial products. The new PEM's with optimized properties are expected to find immediate applications in both hydrogen and direct methanol fuel cells. BENEFITS: The novel proposed electrolytes would allow major advances in small, light and more efficient fuel cells by providing high conductivity and low fuel crossover. Light weight, high energy density fuel cells are needed for powering electric vehicles and for manportable applications. Both defense (future soldier systems), and civilian (electric cars) applications present large potential markets.