Impact of gas diffusion layer spatial variation properties on water management and performance of PEM fuel cells

摘要

In this study, a three-dimensional multi-phase model is developed to numerically investigate the effect of gas diffusion layer spatial variation properties on water management and performance of proton exchange membrane fuel cells. The research mainly focuses on the influence of non-uniform porosity distribution in through plane direction under different operating pressure and anode inlet humidity. Besides, the non-uniform distribution of wettability is also discussed. The results demonstrate that the spatial variation porosity and wettability distribution could affect the saturation profile of liquid water inside the cathode gas diffusion layer and catalyst layer. In addition, higher operating pressure leads to better performance and lower membrane water content, especially for the fuel cells with spatially variable porosity and wettability distribution. Under the operating condition without cathode inlet humidification, higher anode inlet humidity causes higher membrane water content. Finally, the wettability distribution in gas diffusion layer also influences the fuel cells water management and performance, but the influence mechanism of spatially variable wettability is more indirect than porosity.