Phase-Contrast X-ray Images of Ice and Water on Carbon Paper for Fuel Cells Measured by Diffraction-Enhanced Imaging Technique

To develop a novel observation system for water accumulation and freezing in gas diffusion layers (GDLs) of polymer electrolyte fuel cells (PEFCs), phase-contrast X-ray imaging using the diffraction-enhanced imaging (DEI) technique was performed at temperatures between 233 and 293 K. The use of high-energy X-rays of 35 keV in the DEI technique enabled the visualization of ice and meltwater in carbon paper sandwiched by two Al plates of 0.50 mm thickness. It was proven that the DEI technique using a temperature-controlled chamber enables in situ observation of ice and water in GDLs under different temperature conditions, which is critical for achieving high performance PEFCs.