Characterization of Thermal and Electronic Conductivities of Catalyst Layers of Polymer Electrolyte Membrane Fuel Cells

This work proposes new and accurate systematic methodologies for ex situ measurements of through-plane thermal and in-plane electronic conductivities of catalyst layers (CLs) of polymer electrolyte membrane fuel cells (PEMFC). The developed methods are based on measurements of different thicknesses/lengths of a CL on different substrates. Suitability of the proposed methods is confirmed through a set of microstructural properties measurements on a typical CL design to ensure the measured CLs would be representative of CLs in a real fuel cell product. Conductivity measurements of two CL designs with different compositions and microstructures confirm capability of the developed procedures to track structural changes in CLs. The present characterization platform is not limited to CLs and may be used for other composite porous materials with similar structures.