Sr-free orthorhombic perovskite Pr0.8Ca0.2Fe0.8Co0.2O3-δ as a high-performance air electrode for reversible solid oxide cell

Reversible solid oxide cells (RSOCs) as clean and efficient electrochemical conversion and storage devices have received much attention. PrFeO3-δ has been investigated to obtain excellent performance when it is used as air electrode for RSOCs. In this work, we investigate a novel PrFeO3-δ based orthorhombic perovskite oxide Pr0.8Ca0.2Fe0.8Co0.2O3-δ and use it as the air electrode of RSOCs. The electrochemical performance of this cell with Pr0.8Ca0.2Fe0.8Co0.2O3-δ electrode is presented in detail. The highest power density at 850 °C can reach 1.762 W cm−2 in fuel cell mode using hydrogen as fuel. And the electrolysis current density of 2.23 A cm−2 at 850 °C can be achieved under the condition of 50 vol % absolute humidity at 1.3 V in electrolysis cell mode. Moreover, during a long-term operation of up to 200 h, this cell can remain stable and shows good reversibility in two modes. These results demonstrate that the perovskite Pr0.8Ca0.2Fe0.8Co0.2O3-δ is promising air electrode for RSOCs.