Three Dimensional Computational Study on Proton Exchange Membrane Fuel Cell by Operation Conditions

Abstract

A single-phase, fully three-dimensional simulation model for a proton exchange membrane(PEM) fuel cell was used to examine the interdigitated flow field with electrochemical reaction and ion, electron, and water transport(electro-osmotic drag flux and back diffusion flux) through the polymer membrane. The numerical results showed that the fuel cell with an interdigitated flow field resulted in better performance than a fuel cell with a conventional flow field due to its strong convective transport across gas diffusion layer(GDL). However, the pressure drop in an interdigitated flow field is much greater than in conventional flow field. To investigate the effect of relative humidity on the performance of a PEM fuel cell, the humidification condition was set to 100% at the anode flow field and was changed by 0-100% at the cathode flow field. Maximum power density was obtained for a 70% humidified condition at the cathode where the oxygen concentration is moderately high while maintaining high ion conductivity at the polymer membrane.

Keywords

• proton exchange membrane fuel cell
• conventional flow field
• interdigitated flow field
• relative humidity