Clean and Sustainable Power to X to Power by Reversible Symmetrical Solid Oxide Cells with Highly Active Ferrite Perovskite Electrodes

Reversible symmetrical solid oxide cell (RSSOC) exhibits considerable potential for direct power to X and X to power at low cost and enhanced reliability. The electrode with promising electrocatalytic activity is vital to promote its overall performance. Thus, this work explores the La0.6Ca0.4Fe0.8Co0.2O3-δ (LCFC) perovskite oxide for RSSOC. The results demonstrate that the LCFC exhibits promising conductivity (203 S·cm–1) and thermal expansion coefficient (14.3 × 10–6 K–1) as the air electrode. Moreover, the reduced LCFC (fuel electrode) with in situ exsolved Co–Fe alloy nanoparticles exhibits excellent CO2 adsorption ability and sufficient oxygen vacancies. The performance of the LCFC electrode can be significantly enhanced with the good compatibility air electrode and highly active fuel electrode. The cell in the SOFC mode demonstrates outstanding peak power densities of 0.962 and 0.673 W·cm–2 operated with H2 and CO at 800 °C, respectively, while in the SOEC mode, the current densities of 1.631 and 1.574 A·cm–2 can be obtained at 1.5 V with 50% H2O–50% H2 and pure CO2, respectively. The cell also exhibits excellent short-term stability in both the SOFC and SOEC modes. All of the results confirm the feasibility of the LCFC material used for the implementation of RSSOC.