Evaluation of Electrolyte Breakdown Condition in an Anode-Supported SOFC due to Ni-Zirconia Cermet Anode Reoxidation

An emergency shutdown of an SOFC system gives rise to an increase of the anode-side partial pressure of oxygen (p(O-2),a). This leads to electrolyte breakdown due to the anode strain caused by Ni-zirconia cermet reoxidation. We determined the open circuit voltage recovery and drop conditions at various (p(O-2),a)'s and temperatures and clarified the electrolyte breakdown conditions in an anode-supported cell. In addition, we investigated the anode strain under the neighborhood of electrolyte breakdown conditions by dilatometry. The results indicate that the electrolyte was broken when anode strain is over 0.25%.