Hybrid Anion and Proton Exchange Membrane Fuel Cells

A novel hybrid fuel cell is described using at least one electrode operating at high pH in an effort to use the high conductivity of Nafion and exploit the electrochemical advantages of high-pH operation. The electrochemical behavior of a hybrid anion exchange membrane (AEM)/proton exchange membrane (PEM) junction and corresponding fuel cell are presented. Two AEM/PEM junctions and fuel cells have been evaluated: AEM anode/PEM cathode and PEM anode/AEM cathode. The AEM cathode/PEM membrane configuration causes proton-hydroxide recombination at the membrane junction, resulting in self-hydration of the membrane. The fuel cell performance improves at lower relative humidity. At 65 °C and 0% relative humidity, the hybrid cell operates at steady state whereas the performance of a conventional PEM cell decreases with time due to dry-out.