A numerical study of proton exchange membrane fuel cell performances affected by various porosities of gas difussion layer materials

One of the factors that can increase the surface transfer property for gas diffusivity apart from the membrane material in PEMFC is the porosity of the gas diffusion layer material affecting species mass distribution at the electrodes. The present study simulates the performance of PEMFC by investigating the effect of GDL porosities in some commercial ELAT-TEK-1200W (e=0.31), and SIGRACET 25BA (e=0.63), also an organic material coconut coir (e=0.88) numerically. It was carried out using COMSOL Multiphysics 5.3a in the form of species mass concentrations plotted in the surface contour and cut points at the electrodes in the elapsed time transiently. Afterward, the results were used to determine the PEMFC performance by calculating some losses; activation, ohmic, and mass concentration polarization. The results showed that the PEMFC performance was only influenced by the mass polarization. It means that the power density is strongly influenced by the concentration of species in the anode and the cathode. The mass concentration is strongly influenced by the distribution of species; H₂, O₂, and H₂O formed during the reaction. The highest H₂ concentration at the anode occurs in the GDL using ELAT-TEK-1200W having the smallest porosity producing the highest power density compared to other GDL materials. It makes an easier diffusion process between H₂ and O₂ species to work properly. However, coconut coir as an organic material can be a promising GDL in the future because of its performance compared to the others.