Ferritic stainless steel is one of the most promising interconnects for medium and low temperature solid oxide fuel cell (SOFC) due to the excellent properties such as good corrosion resistance, high electrical conductivity and high thermal conductivity. However, at 600-800 operating temperature of SOFC, the chromium-containing stainless steel has problems such as increased interface resistance caused by high-temperature oxidation and Cr element poisoning cathode material. The selection of metal interconnects and the mechanism of Cr poisoning cathodes were briefly described in terms of the types and preparation methods of protective coatings for interconnects. Then, the protective effects of active element oxide coatings, rare earth perovskite coatings and spinel coatings on the interconnects as well as the new research progress in recent years were mainly reviewed. The commonly used preparation methods and characteristics of the surface coatings for SOFC metal interconnect were also summarized. The effect mechanism and application limitations of rare earth element oxide coatings on alloy oxide film were introduced. The advantages and disadvantages of common perovskite coatings were concluded, such as La1–xSrxCrO3, La1–xSrxCoO3, La1–xSrxMnO3, etc. The effects of doping on the performance of perovskite coatings were also analyzed. The effects of transition metal element doping and rare earth element doping on the conductivity of Mn-Co and Cu-Mn spinel coatings and the matching of thermal expansion coefficient as well as the bonding of the coatings were reviewed. Element doping improved the conductivity of spinel coatings and increased the resistance to Cr poisoning to a certain extent, but there were still some issues required to be further resolved, such as the amount of element doping, the long-term stability of coating, etc. Finally, the problem of protective coatings for metal interconnects and the focus of future research work were prospected.Ferritic stainless steel is one of the most promising interconnects for medium and low temperature solid oxide fuel cell (SOFC) due to the excellent properties such as good corrosion resistance, high electrical conductivity and high thermal conductivity. However, at 600-800 operating temperature of SOFC, the chromium-containing stainless steel has problems such as increased interface resistance caused by high-temperature oxidation and Cr element poisoning cathode material. The selection of metal interconnects and the mechanism of Cr poisoning cathodes were briefly described in terms of the types and preparation methods of protective coatings for interconnects. Then, the protective effects of active element oxide coatings, rare earth perovskite coatings and spinel coatings on the interconnects as well as the new research progress in recent years were mainly reviewed. The commonly used preparation methods and characteristics of the surface coatings for SOFC metal interconnect were also summarized. The effect mechanism and application limitations of rare earth element oxide coatings on alloy oxide film were introduced. The advantages and disadvantages of common perovskite coatings were concluded, such as La1–xSrxCrO3, La1–xSrxCoO3, La1–xSrxMnO3, etc. The effects of doping on the performance of perovskite coatings were also analyzed. The effects of transition metal element doping and rare earth element doping on the conductivity of Mn-Co and Cu-Mn spinel coatings and the matching of thermal expansion coefficient as well as the bonding of the coatings were reviewed. Element doping improved the conductivity of spinel coatings and increased the resistance to Cr poisoning to a certain extent, but there were still some issues required to be further resolved, such as the amount of element doping, the long-term stability of coating, etc. Finally, the problem of protective coatings for metal interconnects and the focus of future research work were prospected.Ferritic stainless steel is one of the most promising interconnects for medium and low temperature solid oxide fuel cell (SOFC) due to the excellent properties such as good corrosion resistance, high electrical conductivity and high thermal conductivity. However, at 600-800 operating temperature of SOFC, the chromium-containing stainless steel has problems such as increased interface resistance caused by high-temperature oxidation and Cr element poisoning cathode material. The selection of metal interconnects and the mechanism of Cr poisoning cathodes were briefly described in terms of the types and preparation methods of protective coatings for interconnects. Then, the protective effects of active element oxide coatings, rare earth perovskite coatings and spinel coatings on the interconnects as well as the new research progress in recent years were mainly reviewed. The commonly used preparation methods and characteristics of the surface coatings for SOFC metal interconnect were also summarized. The effect mechanism and application limitations of rare earth element oxide coatings on alloy oxide film were introduced. The advantages and disadvantages of common perovskite coatings were concluded, such as La1–xSrxCrO3, La1–xSrxCoO3, La1–xSrxMnO3, etc. The effects of doping on the performance of perovskite coatings were also analyzed. The effects of transition metal element doping and rare earth element doping on the conductivity of Mn-Co and Cu-Mn spinel coatings and the matching of thermal expansion coefficient as well as the bonding of the coatings were reviewed. Element doping improved the conductivity of spinel coatings and increased the resistance to Cr poisoning to a certain extent, but there were still some issues required to be further resolved, such as the amount of element doping, the long-term stability of coating, etc. Finally, the problem of protective coatings for metal interconnects and the focus of future research work were prospected. © 2022, Chongqing Wujiu Periodicals Press. All rights reserved.
