Analysis of Ionomer-coated Carbon Nanofiber for use in PEM Fuel Cell Catalyst Layers

Abstract

The typical catalyst layer structure for proton exchange membrane (PEM) fuel cells has changed little over the last two decades. A new electrode design with improved control over factors such as ionic and electrical pathways, porosity, and catalyst placement, could allow the application of less expensive catalyst alternatives. In this work, a novel electrode design based on ionomer-coated carbon nanofibers is proposed and studied. Governing equations for this design were established, and a mathematical model was created and solved using MATLAB to predict the performance of the new electrode design. A parametric study was performed to identify the design variables that had the most significant effect on performance. The best performing catalyst layer design studied with this model produces a current density of 1.1 A cm-2 at 600 mV which is better than state-of-the-art cathode designs. The results offer insight into the performance of ionomer-coated carbon nanofiber catalyst layers and can guide the fabrication and testing of these promising catalyst layer structures.