This page contains our work related to single cells of 53 cm2 area. This research is primarily concerned with characterizing flooding and drying conditions within the cell under dead ended anode operation. To this end, data was collected at the NIST Center for Neutron Research to visualize water flooding with an image collection rate of 1 Hz. A Nafion 111-IP membrane was used with carbon cloth gas diffusion layers and graphite impregnated end plates. A wide range of temperatures, current densities, stoichiometries, and gas stream relative humidities were tested. Image masks were employed to determine the spatial distribution of the liquid water and differentiate between anode and cathode flooding and plugging. Below is an example of the imaging data before and following an anode purge.
Large and repeatable transients were observed in the cell voltage and liquid water buildup, indicating a direct relationship between water mass accumulation in the anode channel and voltage degradation. A simple one-dimensional model is used to relate active area reduction to voltage degradation, and shows good correlation in predicting the cell voltage.
Publications featuring this model can be found in the Journal of the Electrochemical Society. See the ‘Publications’ tab for a full citation.