(185b) Prediction of Gas Diffusion Layer Transport Properties and Their Effect on the Performance of PΕΜ Fuel Cells

The effective diffusivity and viscous permeability of the anode and cathode gas diffusion layers (GDL) of the fuel cell are key parameters that determine the rate of mass transport and viscous flow of hydrogen, oxygen, and water vapor through the cell, thereby influencing the supply of reactants to the catalyst layers and the overall performance of the fuel cell. However, a review of recent literature shows that these critical parameters have not received the deserved attention in most fuel cell modeling studies. We present experimentally supported numerical predictions for these properties, and we use them in a two-dimensional mathematical model for a PEM fuel cell, accounting for viscous flow, mass transfer and electrochemical reactions within the gas channels, gas diffusion layers, anode and cathode catalyst layers, and the polymer electrolyte membrane. Our results suggest that the GDL permeabilty values routinely used in the literature may lead to significant errors in the fuel cell modeling predictions, overestimating the current and power density by 100% or more. Additional deviations up to 15% are due to the commonly used effective diffusivity approximations. A PEMFC unit is currently under development to test our predictions, aiming to optimize the operating conditions of the fuel cell and help determine the types of GDL and catalyst materials that will enhance the overall process efficiency.