The Ca element effect on the enhancement performance of Sr2Fe1.5Mo0.5O6−δ perovskite as cathode for intermediate-temperature solid oxide fuel cells

In this paper, the partial substitution of atomic elements from the A site of a perovskite is investigated in order to develop cathode materials for solid oxide fuel cell (SOFC) applications. Herein, Sr2−xCaxFe1.5Mo0.5O6−δ (SCFM), compounds were investigated by characterizing structural properties, chemical compatibility, electrical properties, electrochemical performance and stability. Thermal expansion coefficients were found to decrease when increasing the Ca content. X-ray photoelectron spectroscopy analysis suggests that Ca doping significantly affects the Fe2+/Fe3+ and Mo6+/Mo5+ ratios. For a doping level of x = 0.4, the sample showed the lowest interface polarization (Rp), the highest conductivity and a maximum power density of 1.26 W cm−2 at 800 °C. These results suggest that SCFM cathode materials are excellent candidates for intermediate temperature solid oxide fuel cells applications.