Redox - Cycling - a tool for artificial electrochemical aging of solid oxide cells

In this work a procedure for accelerated stress tests of Solid Oxide Cell (SOC) by artificial aging of the anode via redox cycling is presented. This approach eliminates the interrelation of different degradation processes and ensures a clear picture of the anode degradation on the total cell performance. The level of oxidation is monitored in situ on bare anode samples by impedance measurements of the Ni network resistance changes during oxidation/reduction cycling which ensures governing of the oxidation level with high reproducibility by selection of appropriate experimental conditions. Once fixed on bare anode samples, the selected redox cycling regime is further applied in full cell configuration. The developed methodology is evaluated by comparative analysis of current-voltage and impedance measurements of artificially aged and calendar aged button cells. The results for 8 redox cycles are comparable to those obtained for more than 600 hours operation in standard conditions.