Coating Distribution Analysis on Gas Diffusion Layers for Polymer Electrolyte Fuel Cells by Neutron and X-ray High-Resolution Tomography

Abstract

Coating load and distribution in gas diffusion layers (GDLs) for polymer electrolyte fuel cells (PEFCs) have a major influence on mass transport losses. To be able to optimize the coating distribution and get more accurate data about the influence of the coating on the PEFC performance, better characterization techniques are necessary. Common analysis techniques are limited to selected sections of the material, or they are not sensitive to small amounts of coating. We propose a new methodology to get a complete description of the coating distribution and the GDL structure by combining high-resolution X-ray tomography with high-resolution neutron tomography. Using an isotopic gadolinium staining method to enhance the neutron and X-ray absorption contrast, lower quantities of coating can be detected. The combination of both imaging techniques allows for a more detailed analysis of the coating distribution.