Preparation and characterization of Pr1−xSrxFeO3 cathode material for intermediate temperature solid oxide fuel cells

A kind of cathode material of Pr1−xSrx FeO3 (x = 0–0.5) for intermediate temperature solid oxide fuel cells (IT-SOFCs) was prepared by the coprecipitation method. Crystal structure, thermal expansion, electrical conductivity and electrochemical performance of the Pr1−xSrxFeO3 perovskite oxide cathodes were studied by different methods. The results revealed that Prl−xSrxFeO3 exhibited similar orthorhombic structure from x = 0.1 to 0.3 and took cubic structure when x = 0.4–0.5. The unit cell volume decreased and the thermal expansion coefficient (TEC) of the materials increased as the strontium content increased. When 0 < x ≤ 0.3, the samples exhibited good thermal expansion compatibility with YSZ electrolyte. The electrical conductivity increased with the increasing of doped strontium content. When x = 0.3–0.5, the electrical conductivities were higher than 100 S cm−1. The conductivity of Pr0.8Sr0.2FeO3 was 78 S cm−1 at 800 °C. Compared with the La0.8Sr0.2MnO3 cathode, Pr0.8Sr0.2FeO3 showed higher polarization current density and lower polarization resistance (0.2038 Ω cm2). The value of I0 for Pr0.8Sr0.2FeO3 at 800 °C is 123.6 mA cm−2. It is higher than that of La0.8Sr0.2MnO3. Therefore, Pr1−xSrxFeO3 can be considered as a candidate cathode material for IT-SOFCs.