Development and performance of anode material based on A-site deficient Sr_2-xFe_1.4Ni_0.1Mo_0.5O_6-δ perovskites for solid oxide fuel cells

Engineering of A-site deficiency in perovskites can be critical for designing new materials with required functional properties. In this article, A-site deficient Sr_2-xFe_1.4Ni_0.1Mo_0.5O_6-δ (x = 0-0.1, Sr_2-xFNM) perovskites have been synthesized and characterized as anode materials for solid oxide fuel cells. X-ray photoelectron spectroscopy data indicate that Sr deficiency changes valence states of B-site cations. The introduction of A-site deficiency has shown to improve the chemical stability of the as-prepared materials under reducing conditions. With increasing of Sr deficiency, the conductivity in 5% H₂/Ar increases markedly, reaching a peak value of 26.6 S cm⁻¹ at x = 0.05. While further increasing of x reduces the conductivity by affecting the mobility of electronic charge carriers. The La_0.9Sr_0.1Ga_0.8Mg_0.2O₃ electrolyte-supported cell with La_0.6Sr_0.4Fe_0.8Co_0.2O₃ cathode and Sr_1.95Fe_1.4Ni_0.1Mo_0.5O_6-δ anode demonstrates a maximum power density of 606 mW cm⁻² at 800 °C operating in H₂. Such designed A-site deficiency perovskite has the potential to be applied as SOFC anode materials.