Capturing the Microstructural Complexities of PEMFC Catalyst Layers and Local Transports Therein Using Network Modeling Approach

Abstract

The microstructural characteristics of the catalyst layer are critical for understanding the effect of local transport processes (water, reactant gas, and proton transport) in catalyst layers on overall PEMFC performance. Here, we present a network architecture that uses structured networks to capture the morphological heterogeneity of PEMFC catalyst layers. Using the poroelastic theory of swelling, it depicts how the ionomer within the catalyst layers absorbs water and expands in volume with respect to humidity which dictates the shift in porosity and pore size distribution of the catalyst layers. Local transport behavior (flooding, reactant gas, and proton starvation at the reaction sites) under different PEMFC operating conditions are analyzed by applying transport equations to the generated networks.