Modeling Study for Investigation of Saturation Effect on Cell Performance in PEM Fuel Cells

In the present work, the saturation influence of the cathode catalyst layer (CCL) of proton exchange membrane fuel cell (PEMFC) on cell performance is studied. For this mean, a steady- state, macro-homogeneous catalyst layer (CL) model is used to investigate the effect of various saturation conditions. This model solves the governing equations for the oxygen diffusion; the rate of electrochemical reactions; and transports of protons and electrons through the membrane and solid phases, respectively. The cathode CL contains: membrane, solid, catalyst particles and void spaces. The void spaces are assumed to be various saturation of liquid water (100, 70 and 50%); therefore, the oxygen species must diffuse in liquid- and vapor-water and ionomer phase to reach to the active sites. Simulation results show that cathode CL saturation plays very important role on the PEMFC performance. Improved performances are achieved at saturation levels of CCL 50 to 70%, as oxygen diffuses in vapor much easier than in fully flooded CCL

کلیدواژه ها:

PEM fuel cell ، Catalyst layer ، saturation