Degradation studies of ceria-based solid oxide fuel cells at intermediate temperature under various load conditions

Abstract Despite several disadvantages with the electronic conduction of ceria, researchers report the high performance of ceria-based solid oxide fuel cells (SOFCs) at intermediate temperatures with advanced cathode materials. However, it appears the long-term stability of ceria-based SOFCs in the anode-supported cell configuration have still not been proved experimentally at practical operating conditions. In particular, the chemical expansion of ceria electrolytes can cause potentially irreversible failure of SOFCs under large P O 2 gradients. Hence, we investigate the degradation behavior of NiO-Nd0.1Ce0.9O2-δ anode-supported cells with Nd0.1Ce0.9O2-δ electrolyte in dynamic electrical modes, load trip (0.7–0 A cm−2), load cycle (0.2–0.12 A cm−2), and constant load operation (0.2 A cm−2), at 650 °C. We identify the specific degradation phenomenon of ceria-based cells by analyzing the electrochemical characteristics in post-mortem investigations after durability testing under various electrical load conditions. Additionally, we suggest a possible operation strategy to mitigate the performance degradation of cells under various electrical stresses through understanding of the main degradation mechanism.