A highly active and stable cobalt-free Iron-based perovskite cathode for solid oxide electrochemical cells.

The limited activity and durability of iron-based perovskite electrodes have significantly hindered their application in solid oxide electrochemical cells (SOCs). Herein, Mn and P co-doped SrFeMnPO (SFMP, x = 0, 0.05, 0.10, 0.15) perovskites were prepared and systematically investigated as cathode materials for both solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs). The results demonstrate that Mn and P co-doping effectively regulates the grain size of SrFeO (SF) materials, promotes the generation of oxygen vacancies, and enhances the adsorption and dissociation of oxygen, thus significantly improving the electrochemical performance. At 800 °C, SFMP exhibited an R of 0.078 Ω cm, representing a 43.48 % reduction compared to SF, while its output performance improved by 140.43 %, reaching 938.02 mW cm. The SOEC cell with the SFMP electrode demonstrated excellent CO electrolysis capabilities, achieving a current density of 1.73 A cm at 800 °C and 1.5 V. Furthermore, both SOFC and SOEC cells incorporating the SFMP electrode exhibited outstanding performance stability. These findings suggest that co-doping with metal and non-metal cations serves as a promising approach to improve the electrode performance for both SOFCs and SOECs.