Electrochemical properties of La(0.5)Sr(0.5)Fe(0.95)Mo(0.05)O(3−δ) as cathode materials for IT-SOEC

Solid oxide electrolysis cells (SOECs) are a new type of high-efficiency energy conversion device that can electrolyze CO(2) efficiently and convert electricity into chemical energy. However, the lack of efficient and stable cathodes hinders the practical application of CO(2) electrolysis in SOECs. Herein, a novel perovskite oxide La(0.5)Sr(0.5)Fe(0.95)Mo(0.05)O(3−δ) (LSFMo) is synthesized and used as a cathode for SOECs. The introduction of Mo significantly improves the CO(2) tolerance of the material in a reducing atmosphere and solves the problem of SrCO(3) generation in the La(0.5)Sr(0.5)FeO(3−δ) material. Mo ion doping promotes the conductivity in a reducing atmosphere and increases the oxygen deficiencies of the material, which lowers the ohmic resistance (R(s)) of the material and significantly improves the CO(2) adsorption and dissociation in the middle-frequency of polarization resistance (R(p)). For example, R(p) decreases from 0.49 to 0.24 Ω cm(2) at 800 °C under 1.2 V. Further, the reduction of R(s) and R(p) increases the performance improvement, and the current density is increased from 1.56 to 2.13 A cm(−2) at 800 °C under 2 V. Furthermore, LSFMo shows reasonable short-term stability during the 60 h stability test.