Probing ionomer distribution in PEMFC catalyst layers: AFM and DEM enabled microstructure analysis

Proton Exchange Membrane Fuel Cell (PEMFC) catalyst layers have been probed experimentally and theoretically for decades. However, existing microscopy techniques lack the ability to perform quantitative analyses on the catalyst and ionomer distributions of catalyst layers. Since the microstructure of the catalyst layer has an influence on the electrochemical performance, the simulation of catalyst layer microstructures is of great importance. A physics-based simulation model was recently reported to predict the microstructure of the catalyst layer as a function of ink composition. We propose a workflow to characterize catalyst layers with the utilisation of Atomic Force Microscopy. The novelty of the workflow lies in the calculation of a statistical description of the catalyst layer (CL). This statistical metric is then used as a validation metric for a microstructural physics-based simulation model. The resulting simulation workflow can be used to predict the ink composition required to obtain catalyst layers with desired microstructural properties, paving the way towards more efficient PEMFCs.