Abstract
During cold startup of polymer electrolyte fuel cell (PEFC), water freezing in a cathode porous electrode is a critical barrier to achieve high power density, because ice particles in the catalyst layer (CL) and gas diffusion layer (GDL) block oxygen transport to the active reaction sites. In this study, we investigate water behavior inside a cathode electrode of PEFC at low temperature operations using an optical diagnostic, and show the effect of the mechanism of water freezing on the characteristic of cell voltage. The results showed that ice formation in cathode electrode during cold startup is largely affected by GDL structure.
