Understanding Degradation Phenomena in HT-PEM Fuel Cells Using Micro-Computed Tomography

An extended and reliable lifetime of high temperature proton exchange membrane fuel cells is inevitable for the commercialization of this technology in the near future. Therefore, components of the high temperature-proton exchange membrane fuel cell (HT-PEMFC), such as the bipolar plates (BPPs) and the membrane electrode assembly (MEA), are investigated regarding degradation phenomena during constant cell operation with use of contaminated air in the cathode feed. µ-computed tomography (µ-CT) is applied to visualize morphological changes due to this operation and to analyse each component individually on the micro meter scale. The thickness of each MEA layer is determined and correlated to results from electrochemical measurements. Furthermore the open porosity of the bipolar plates is determined and compared to phosphoric acid retention of the cell.