B-Site Super-Excess Design Sr2V0.4Fe0.9Mo0.7O6−δ-Ni0.4 as a Highly Active and Redox-Stable Solid Oxide Fuel Cell Anode

In-situ exsolution type perovskites as solid oxide fuel cell (SOFCs) anode materials have received widespread attention because of their excellent catalytic activity. In this study, excessive NiO is introduced to the Sr2V0.4Fe0.9Mo0.7O6-δ (SVFMO) perovskite with the B-site excess design, and in-situ growth of FeNi3 alloy nanoparticles is induced in the reducing atmosphere to form the Sr2V0.4Fe0.9Mo0.7O6-δ-Ni0.4 (SVFMO-Ni0.4) composite anode. Here, with H2 or CH4 as SOFCs fuel gas, the formation of FeNi3 nanoparticles further enhances the catalytic ability. Compared with SVFMO, the maximum power density (Pmax) of Sr2V0.4Fe0.9Mo0.7O6-δ-Ni0.4 (SVFMO-Ni0.4) increases from 538 to 828 mW cm-2 at 850 °C with hydrogen as the fuel gas, and the total polarization resistance (RP) decreases from 0.23 to 0.17 Ω cm2. In addition, the long-term operational stability of the SVFMO-Ni0.4 anode shows no apparent performance degradation for more than 300 h. Compared with SVFMO, the Pmax of SVFMO-Ni0.4 increases from 138 to 464 mW cm-2 with methane as fuel gas, and the RP decreases from 1.21 to 0.29 Ω cm2.