Investigation of Cu/F co-doped Sr2Fe1.5Mo0.5O6−δ cathode for solid oxide fuel cells

In this paper, a novel Cu/F co-doping strategy is proposed to modify the electrochemical performance of Sr 2 Fe 1.5 Mo 0.5 O 6– δ (SFM) cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The pristine SFM, Cu-doped Sr 2 Fe 1.4 Cu 0.1 Mo 0.5 O 6− δ (SFCM) and Cu/F co-doped Sr 2 Fe 1.4 Cu 0.1 Mo 0.5 O 5.9− δ F 0.1 (SFCMF) powders were synthesized by acid-glycine combustion method, and the impacts of Cu/F co-doping on the performance of SFM cathode were investigated systematically. It's found that Cu-doped SFCM has higher oxygen vacancy content and electrical conductivity than the pristine SFM and Cu/F co-doped SFCMF cathodes. While the Coulombic force between B-sites metallic ions and oxygen ions are significantly weaken for SFCMF, enhancing the mobility of lattice oxygen. Due to the combined effects of Cu and F doping, SFCMF cathode exhibits the best electrochemical performance among all investigated samples. At 600 °C, the polarization resistant for SFCMF cathode is 1.79 Ω cm 2 , decreased by 43.71 % in contrast to the parent SFM cathode. These results indicate that Cu/F co-doping is an effective strategy to improve the electrochemical properties of perovskite cathode materials.