Progress in metal corrosion mechanism and protective coating technology for interconnect and metal support of solid oxide cells

Solid oxide cell (SOC) is an important technology for hydrogen energy utilization. Durability and reliability of metal components including interconnect and metal support of metal-supported SOC are key requirements for the massive production of SOCs. Metal corrosion and electrode poisoning caused by elements diffusion under high-temperature working conditions are two main issues. This review concentrates on the anti-corrosion technology of interconnects and metal supports. First, the characteristics of stainless-steel materials commonly used in SOCs and the corrosion mechanisms under oxidizing, reducing, and dual atmospheres are introduced. Relevant elements interdiffusion and metal creep degradation are presented. Then, typical protective coating materials incorporating reactive element oxides, perovskites, and spinels are reviewed. Two composite coatings having a mixture or bilayer structure are discussed. Deposition processes involving electroplating, electrophoresis, magnetron sputtering, pulsed laser deposition, electron beam evaporation, screen printing, sol-gel coating, and plasma spraying are summarized and compared. Finally, challenges and future research directions are highlighted.