LSF films formed on YSZ electrolytes via polymeric precursor deposition for solid oxide fuel cell anode applications

Different materials have been applied as anode in solid oxide fuel cell (SOFC). Perovskite structured materials are promising as an alternative electrode material to Ni. Here, we investigated perovskite-structured mixed ionic and electronic conducting material, lanthanum strontium ferrite (LSF), which has typically been used as a cathode material. LSF has also shown potential for an anode in SOFC. LSF films with two different compositions, La_0.6Sr_0.4FeO₃ (6LSF) and La_0.8Sr_0.2FeO₃ (8LSF) were fabricated by a polymeric precursor method. The effects of the phase content, surface chemistry, and microstructure on the anode performance were investigated. It was found that a mixture of the Ruddlesden–Popper phase, SrCO₃ phases, and rhombohedral perovskite exists in both cell structures. Both cells had Ruddlesden–Popper and SrCO₃ phases at their surface, in addition to the rhombohedral perovskite. Symmetrical half-cell measurements showed that the polarization resistance of 6LSF (0.34 Ω cm²) is lower than that of 8LSF (0.47 Ω cm²), mostly because of its highly porous microstructure as a result of slower A-site diffusion rates induced by higher Sr content. The symmetrical 6LSF fuel and air electrodes exhibited ASR_electrode values of 0.34 and 0.14 Ω cm², respectively, at 800 ˚C.