Markötter, H.; Manke, I.; Kuhn, R.; Arlt, T.; Kardjilov, N.; Hentschel, M.P.; Kupsch, A.; Lange, A.; Hartnig, C.; Scholta, J.; Banhart, J.: Neutron tomographic investigations of water distributions in polymer electrolyte membrane fuel cell stacks . Journal of Power Sources 219 (2012), p. 120-125

Neutron tomography was applied to study the 3D water distribution in full polymer electrolyte membrane fuel cell (PEMFC) stacks. The water distribution after switch-off of the fuel cell was analyzed over a period of 36 h. We found a slowly increasing water amount in the fuel cell, but only few changes within a time period of 5 h, which is about the time necessary for neutron tomography. In this way, the requirement for successful tomography was obtained. It is demonstrated how the quasi in-situ tomography technique enables us to study the water content in individual flow field channels of three-fold stacks. Flow field as well as stack design issues are addressed by this visualization method showing weak points due to a non-uniform water distribution that can be identified by means of neutron imaging.