Balance the conductivity and enhance chemical stability of BaCe0.3Fe0.7O3–δ by tuning A-site cation deficiency

Abstract

Triple-conducting perovskites are the focus of extensive research and have emerged as high-performance cathode materials for proton-conducting solid oxide fuel cells (H–SOFCs). Notably, BaCe0.36Fe0.64O3-δ (BCF36) has recently garnered attention for its ability to provide suitable oxygen ion conductivity and proton conductivity, all through skillful composition tuning. Here, A-site deficient BaCe0.3Fe0.7O3-δ (D-BCF30) is prepared to further boost the cathode activity. The composition content is modified by introducing Ba cation deficiency according to XRD and calculation results. Remarkably, the single cell equipped with D-BCF30 cathode demonstrates a significantly enhancement in performance, featuring a high power density of 1425 mW cm−2 and a low polarization resistance of 0.045 Ω cm2 at 700 °C compared to stoichiometric BCF30. Moreover, the cell operation durability has markedly improved which is further substantiated through experiments and density functional theory (DFT) calculations, suggesting a promising avenue to improve performance and stability of H–SOFCs.