Composite Nafion/polyvinyl alcohol membranes for the direct methanol fuel cell

The methanol crossover in the direct methanol fuel cell (DMFC) can be reduced by casting a thin film containing the mixture of polyvinyl alcohol (PVA) and Nafion on a commercial perfluorosulfonic membrane (Nafion, Dupont). In addition to the cell polarization testing, a design factor defined as the reciprocal of the multiplication of the methanol permeation current density and membrane area resistance, was used to evaluate the membrane’s performance. Our study has shown that at the weight ratio of 1:1 in PVA and Nafion, the thin film-coated Nafion membrane exhibits low methanol crossover and the membrane conductance can be improved by the sulfonation treatment.