ZHANG Xuebai, JIN Yingmin, JIANG Yunjian, ZONG Xin, LI Yumeng, XIONG Yueping
(School of Chemical Engineering and Chemistry, Harbin Institute of Technology, Harbin 150000, Heilongjiang, China)

Abstract: Solid oxide electrolysis cell (SOEC) is an energy conversion device that can directly convert electric energy into chemical energy stored in fuel gas, with high energy conversion efficiency. The combination of SOEC and solid oxide fuel cell (SOFC) can solve the problem of intermittent power generation from emerging clean energy such as wind energy and solar energy. When the power generation reaches peak, the excess power could be stored in fuels with SOEC, while the power is supplemented with SOFC at the ravine. Hydrogen is a suitable energy carrier because of its high energy density, cleanness and environmental friendliness. Single SOEC is composed of an air electrode, an electrolyte and a fuel electrode. In the process of hydrogen production through SOEC electrolysis, the slow oxygen precipitation kinetic rate of air electrode seriously affects the production rate of hydrogen, while the degradation of the air electrode also leads to the attenuation of SOEC after long-term operation. Therefore, the performance of the air electrode is very important for the application of SOEC. The research progress of air electrode in SOEC steam electrolysis is reviewed from two aspects: oxygen ion conductor electrolyte SOEC (O-SOEC) and proton conductor SOEC (H-SOEC). The air electrode materials of O-SOEC and H-SOEC are systematically sorted out, the electrochemical properties and stability of different materials are compared, the effective strategies to improve the performance and stability of the air electrode are summarized, and the development of SOEC air electrode is prospected.
Key words: solid oxide electrolysis cell; air electrode; steam electrolysis; electrochemical performance; stability