Investigation of cobalt-free perovskite Sr2FeTi0.75Mo0.25O6−δ as new cathode for solid oxide fuel cells

The performance of Sr 2 FeTi 0.75 Mo 0.25 O 6− δ (SFTM) as a potential cathode material has been investigated in this study. The SFTM material with a cubic perovskite structure, has a good chemical compatibility with the Ce 0.8 Sm 0.2 O 1.9 (SDC) electrolyte at 1100   °C for 10   h. The electrical conductivity of the SFTM sample reaches a maximum value of 2.31   S   cm −1 at 500   °C. SFTM shows an average thermal expansion coefficient (TEC) of 13.6   ×   10 −6   K −1 in the temperature range of 30–1000   °C in air, which is close to that of the typical electrolyte material. The polarization resistance ( R p ) of a SFTM cathode on a SDC electrolyte reaches a value of 0.14   Ω   cm 2 at 800   °C. Peak power density of a single-cell with the SFTM cathode on a 300   μm-thick SDC electrolyte reaches 394   mW   cm −2 at 800   °C. These results indicate that SFTM is a potential cathode material for solid oxide fuel cells.