Effect of micro-porous layer on PEM fuel cells performance: Considering the spatially variable properties

Abstract

As the key components that provide path for reactant and water transportation, the impact of gas diffusion layer (GDL) and micro-porous layer (MPL) on the performance of proton exchange membrane fuel cells (PEMFCs) has been extensively investigated. However, as a non-uniform porous medium, the study considering real spatially variable properties of GDL and MPL is really insufficient. In order to investigate the role of MPL with real spatially variable properties on PEMFCs performance and water management, a three-dimensional multi-phase model, which couples the catalyst layer agglomerate sub-model, is developed. It is found the uniform medium assumption for GDL and MPL might overstate the fuel cells performance when the output voltage is higher than 0.5V, especially under the high inlet relative humidity (RH). Besides, the spatially variable properties cause non-uniform distribution of liquid water and there are some saturation peaks in the middle or sides of GDL. Finally, the impact of inlet RH under different types of GDL and MPL is also discussed. From the perspective of the real spatially variable properties of GDL and MPL, this research provides a new approach to explore the influence mechanism of MPL.