Abstract
To develop a high performance direct methanol fuel cell (DMFC), a novel electrolyte membrane is needed. This electrolyte membrane should be durable up to 130t to improve the catalytic reaction, and the methanol crossover should be reduced. Reported membranes are reviewed in this article, and our own approach is shown. Our approach is to design a pore-filling type polyelectrolyte membrane, where the polyelectrolyte is filled into the pores of a porous substrate, and the membrane swelling is suppressed by the substrate matrix. Proton conductivity was achieved through the filling electrolyte polymer. Methanol permeation was controlled by the swelling of the electrolyte polymer, and the mechanical strength at high temperature was maintained by the substrate. From this concept, a high proton conductivity was shown to exist with reduced membrane methanol permeability, and in addition, a heat-resistance was also achieved.
