Characterization of Bipolar Ion Exchange Membrane for Polymer Electrolyte Fuel Cells

Abstract

A new polymer electrolyte fuel cell with a bipolar membrane was proposed with a view to increasing the performance of low temperature PEFCs. The bipolar membrane consists of an acid and a basic ion-exchange layers. The acid layer contacts to the anode and the basic layer contacts to the cathode. The observed open circuit voltage with the proposed cell was 0.882 V. The result implies that the modification of a bipolar membrane fuel cell may leads to a high performance fuel cell. It was observed that the OH⁻ ion conductivity with a basic ion-exchange membrane Neosepta was comparable to the conductivity of H⁺ in Nafion membrane. In the bipolar membrane, however, the measured conductivity was 1 order lower than that of Nafion membrane. This result would be caused by the existence of a resistance layer between the acid and the basic polymer layers. The polarization characteristics were measured by considering the MEA preparation methods. We achieved the polarization performance for the bipolar electrolyte fuel cell using screen-printing MEA preparation method. The highest power density was 0.026 W cm⁻².