Effective Electrode Edge Protection for Proton Exchange Membrane Fuel Cell Drive Cycle Operation

Drive cycle (DC) tests employ rapid load cycling which will result in rapidly changing local operating conditions and consequently high non-uniform mechanical stress at the electrode perimeter. In order to better investigate the impact of electrode irregularities on the long-term behavior of the cell, it is necessary to exclude the edge effects of the membrane electrode assemblies (MEAs) as a failure mode. Therefore, an effective electrode edge protection technique using thin protective gaskets and a hot-pressing procedure was developed which dramatically prolonged lifetime. Open circuit voltage (OCV), air polarization curve, and hydrogen crossover limiting current density were monitored during the DC tests. For post-DC ex-situ analysis, an in-house developed pinhole detection apparatus (1) was employed to analyze quantity, size, and location of the failure points of MEAs with and without edge protection. Non-protected MEAs typically developed tears at the electrode perimeter, while the longer-lasting protected MEAs exhibited seemingly random pinhole development.