Numerical Optimization of Triple-Phase Components in Order-Structured Cathode Catalyst Layer of a Proton Exchange Membrane Fuel Cell

Abstract

Proton exchange membrane fuel cell (PEMFC) is generally regarded as a promising energy conversion device due to its low noise, high efficiency, low pollution, and quick startup. The design of the catalyst layer structure is crucial in boosting cell performance. The traditional catalyst layer has high oxygen transmission resistance, low utilization rate of Pt particles and high production cost. In this study, we offer a sub-model for an order-structured cathode catalyst layer coupled to a three-dimensional (3D) two-phase macroscopic PEMFC model. In the sub-model of the cathode catalyst layer, it is assumed that carbon nanowires are vertically arranged into the catalyst layer structure, platinum particles and ionomers adhere to the surface, and water films cover the cylindrical electrode. The impacts of triple-phase contents in the catalyst layer on cell performance are investigated and discussed in detail after the model has been validated using data from existing studies. The results show that when the triple-phase contents ratio of the order-structured cathode catalyst layer is the best, the overall cell power density of the cell can be maximized, that is, the Pt loading of 0.15 mg cm−2, carbon loading of 1.0 mg cm−2, and ionomer volume fraction of 0.2. The above study may provide guidance for constructing the PEMFC catalyst layer with high catalyst utilization and high performance.