Current distribution uniformity enhancement and analysis in PEMFC through local adjustment with heterogeneously arranged gas diffusion layer: An experimental and numerical study

Abstract

Current distribution uniformity in a polymer electrolyte membrane fuel cell (PEMFC) is improved by heterogeneously arranged gas diffusion layer (GDL). A segmented PEMFC experimental setup is established to measure current distribution and local electrochemical impedance spectroscopy (EIS). In segmented PEMFC experiments, the current distribution and local EIS are measured, demonstrating that heterogeneously arranged GDL induces changes in PEMFC internal parameters and enhance the uniformity of current distribution. In addition, a PEMFC numerical model, including a mass transport model and an electrochemical reaction model, is developed and validated. The model provides a detailed analysis of internal parameters that are challenging to measure in-situ, specifically investigating local variations induced by heterogeneously arranged GDL. Experimental and numerical results demonstrate that various parameters in PEMFC are influenced by the characteristics of GDL used. In addition, the trends in current distribution changes due to heterogeneously arranged GDL are categorized into three cases based on the water content in PEMFC. Although the trend in current distribution changes varies with the water content in PEMFC, heterogeneously arranged GDL exhibits the most uniform current distribution under most operating conditions. Specifically, when the relative humidity of supplied hydrogen and air are 100% and 50%, respectively, and the current load is 32A, heterogeneously arranged GDL shows approximately 51.7% and 6.1% improved current distribution uniformity compared to the two other GDLs that are not heterogeneously arranged GDL.