Non-isothermal multi-dimensional direct methanol fuel cell model with micro-porous layers mitigating water/methanol crossover

Abstract

A two-phase three-dimensional direct methanol fuel cell (DMFC) model with the capability of saturation jump is developed in order to investigate the effect of micro-porous layers (MPL) on the water/methanol crossover in a DMFC. It is found that hydrophobic MPL on the cathode side helps cathode catalyst layer reserve water whereas hydrophobic MPL on the anode side blocks liquid flow to the cathode side, which effectively reduces water/methanol crossover. As the water transport in a DMFC occurs in two-phase, energy equation considering the heat-pipe effect with latent heat is solved together. Calculation result revealed thermal conductivity of gas diffusion layer has a strong influence on both temperature and water transport. Finally, a large-scale simulation of 28 cm2 cell is conducted to examine current density and fuel concentration distribution.