SrCo0.85Fe0.1P0.05O3−δ perovskite as a cathode for intermediate-temperature solid oxide fuel cells

Abstract

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, O₂-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.