A review of the chemical compatibility between oxide electrodes and electrolytes in solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are solid-state environmentally friendly power generation devices with high energy conversion efficiency. Their commercialization has been affected by long-term stability problems. In recent years, to solve the long-term stability problems of traditional Ni-based cermet anodes, increasing attention has been given to oxide ceramic anodes due to their excellent impurity poisoning resistance, carbon deposition resistance and excellent structural stability in both oxidizing and reducing atmospheres. In addition, the cathode material of SOFCs is also composed of oxide ceramic materials with high conductivity and good catalytic activity for the oxygen reduction reaction (ORR). However, there are some problems, such as interface reactions or the interdiffusion of elements between oxide electrodes and oxide electrolytes at high temperature, which are the key issues affecting the long-term stability of SOFCs. In recent years, many studies have proposed relevant mechanisms and solutions. For example, in perovskite oxide materials with ABO3 structures, the elemental ratio of A/B and cation deficiency at A-sites and B-sites can significantly affect the high temperature chemical compatibility between the oxide electrodes and electrolytes. In this review, the interface compatibility between oxide electrodes and ceramic electrolytes in SOFCs, interfacial reactions, interdiffusion and corresponding suppression mechanisms are reviewed.