Characterization and Modeling of Gas Crossover and its Impact on the Membrane Degradation of PEMFCs

Abstract

Membrane degradation was investigated by accelerated membrane degradation tests in various gas-supply conditions. Results show that the anode side of the membrane was more deteriorated under H2-O2 supply conditions. However, the cathode side of the membrane was more deteriorated under H2-air supply conditions. Quantitative examination of the oxygen crossover by direct gas mass spectroscopy (DGMS) elucidated that the oxygen crossover depends on the oxygen partial pressure and relative humidity of the supplying gas. Based on membrane degradation and oxygen crossover, we modeled membrane thinning with a simple rate equation with the effect of partial pressure. Calculated values of membrane thinning were consistent with the experimental values.