Markötter, H.; Manke, I.; Haußmann, J.; Arlt, T.; Klages, M.; Krüger, P.; Hartnig, C.; Scholta, J.; Müller, B.R.; Riesemeier, H.; Banhart, J.: Combined synchrotron X-ray radiography and tomography study of water transport in gas diffusion layers. Micro and Nano Letters 7 (2012), p. 689-692

Synchrotron X-ray radiography and tomography investigations of a custom-made polymer electrolyte membrane fuel cell optimized for visualization purposes are presented. The 3D water distribution and transport pathways in the porous carbon fiber gas diffusion layers (GDLs) were investigated. We found that water is not only moving from the GDL into the channel, but can also take the opposite way, i.e. from the channel into free pore space of the GDL. Such movement of water into the opposite direction has been subject of speculations but has so far not yet been reported and might bring new insights into the general water transport behavior, which might give new aspects to the general description of water transport processes and influence modeling assumptions to describe the process taking place in the GDL.