SrCo_0.85Fe_0.1P_0.05O_3-δ perovskite as a cathode for intermediate-temperature solid oxide fuel cells

In this paper a phosphorus doped perovskite, SrCo_0.85Fe _0.1P_0.05O_3-δ (SCFP), is evaluated as a cathode material for intermediate-temperature solid oxide fuel cells. It is observed that the phosphorus dopant can prevent the Sr-Co-Fe-O system from oxygen vacancy ordering and stabilise the crystallite structure of the oxide in the 3C perovskite phase at high temperature as proved by XRD, TGA, O ₂-TPD and electrical conductivity characterization. SCFP shows excellent chemical compatibility with Sm_0.2Ce_0.8O _1.9 (SDC) electrolyte even at 1200 °C. The oxygen reduction reaction (ORR) activity is investigated on a dense SDC pellet in a symmetrical cell configuration, and the area specific resistance (ASRs) of SCFP is as low as 0.097 Ω cm² at 589 °C, which is comparable to the performance of the benchmark cathode BSCF. The stabilised structure for SCFP also improves the stability of the ORR activity at high temperature.