Abstract
An experimental study using a sub-scale single cell was carried out to investigate the issues of concentration overvoltage due to oxygen transport under high current density operation of proton exchange membrane fuel cell. The result shows that the oxygen mole fraction drop in the cathode occurred mainly in the substrate of GDLs and the contribution of it to the overall diffusion is obtained as 60%. In addition, observation of porous structure of GDL by scanning electron microscope shows that the oxygen diffusion in GDLs is strongly affected by porous structure.
