B-Site Super-Excess Design Sr₂V_0.4Fe_0.9Mo_0.7O_6-δ-Ni_0.4 as a Highly Active and Redox-Stable Solid Oxide Fuel Cell...

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 Sr₂V_0.4Fe_0.9Mo_0.7O_6-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 Sr₂V_0.4Fe_0.9Mo_0.7O_6-δ-Ni_0.4 (SVFMO-Ni_0.4) 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 (P_max) of Sr₂V_0.4Fe_0.9Mo_0.7O_6-δ-Ni_0.4 (SVFMO-Ni_0.4) increases from 538 to 828 mW cm^-2 at 850 °C with hydrogen as the fuel gas, and the total polarization resistance (R_P) decreases from 0.23 to 0.17 Ω cm². In addition, the long-term operational stability of the SVFMO-Ni_0.4 anode shows no apparent performance degradation for more than 300 h. Compared with SVFMO, the P_max of SVFMO-Ni_0.4 increases from 138 to 464 mW cm^-2 with methane as fuel gas, and the R_P decreases from 1.21 to 0.29 Ω cm².