Highly Stable and Efficient Perovskite Ferrite Electrode for Symmetrical Solid Oxide Fuel Cells.

Here, we report a new perovskite oxide with formula Sm0.8Sr0.2Fe0.8Ti0.15Ru0.05O3-δ (SSFTR), which exhibits a great potential as a symmetrical electrode material with satisfying stability in both reducing and oxidizing environments. Moreover, SSFTR exhibits good redox and thermal cycle stability. The electrolyte-supported (Sm0.2Ce0.8O1.9, SDC) symmetrical cell with SSFTR electrodes possesses a peak power density of 271 mW·cm-2 at 800 °C in wet H2. Moreover, the peak power density is remarkably improved to 417 mW·cm-2 when applying A-site-deficient perovskite oxide Sm0.7Sr0.2Fe0.8Ti0.15Ru0.05O3-δ as the symmetrical electrode, benifiting by the in situ-exsolved Ru nanoparticles with excellent electrocatalytic activity, since A-site deficiency can provide additional driving force for the exsolution of B-site cations upon reduction. As an ingenious approach, this exsolution of electrocatalytically active nanoparticles on the surface of electrode may be applicable to the development of other excellent performance electrodes for symmetrical SOFCs and other electrochemical systems.