Simulation on cathode catalyst layer in proton exchange membrane fuel cell: Sensitivity of design parameters to cell performance and oxygen distribution

The microstructure tuning of the cathode catalyst layer (CCL) is crucial for proton exchange membrane fuel cell (PEMFC) performance. However, a great number of studies have been devoted to the qualitative analysis of CCL design parameters and there is a lack of quantitative studies. In this paper, a cross-dimensional PEMFC agglomerate model is developed to investigate the sensitivities of the CCL design parameters to cell performance and oxygen distribution. Although the results exhibit that the impact of Pt loading on cell performance accounts for 50.7%, the total impact of the Pt radius and I/C ratio (I/C) is as high as 44.9% under the current density of 1000 mA cm(-2). In addition, the variation in I/C directly affects the CCL porosity and thickness of the ionomer on the Pt surface, which determines the oxygen distribution. Typically, under a current density of 1000 mA cm(-2), the impacts of I/C on the average and standard deviation of oxygen concentration account for 42.3% and 51.3%, respectively. The sensitivities of the parameters evolve with the increase in the current density. Pt loading and I/C dominate the cell performance, respectively, with 1200 mA cm(-2) as the demarcation point. This study points out the optimization direction for the design of high-performance CCL. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.