Modeling and sensitivity analysis of high temperature PEM fuel cells by using Comsol Multiphysics

• The effect of inlet gas velocities of hydrogen and air on high temperature PEM fuel cell performance.
• The effect of conductivity of polymeric membrane on high temperature PEM fuel cell performance.
• Modeling of high temperature PEM fuel cell by Comsol Multiphysics.

The objective of this study is to observe the effect of the critical design parameters, velocities of inlet gases (hydrogen and air) and the conductivity of polymer membrane, on the performance of a high temperature PEM fuel cell. A consistent and systematic mathematical model is developed in order to study the effect of these parameters. The model is applied to an isothermal, steady state, three-dimensional PEM fuel cell in order to observe concentration profiles, current density profiles and polarization curves. The model includes the transport of gases in anode and cathode gas flow channels, diffusion in the catalyst layers, the transport of water and hydronium ion in the polymer electrolyte and in the catalyst layers, and the transport of electrical current in the solid phase. The model is considered as having a single flow channel. The simulation is performed by using licensed Comsol Multiphysics 5.0, Fuel Cells &Batteries Module. The results compare well with the experimental polarization data obtained at 160 °C for ohmic and activation regions. The best match with the experimental data is obtained when the inlet hydrogen gas velocity is 0.133 m/s whereas inlet air velocity is 1.3 m/s for proton conductivity of 10 S/m.