SrCo1−xSbxO3−δ cathode materials prepared by Pechini method for solid oxide fuel cell applications

Abstract In this study, SrCo 1− y Sb y O 3− δ powders were prepared by a modified Pechini method. According to the study results, the cubic Pm3m phase of the SrCo 1− y Sb y O 3− δ ceramics was obtained as 10% of cobalt ions were substituted by antimony ions. Doping of Sb 3+ ions appeared both to stabilize the Pm3m phase of the SrCo 1− y Sb y O 3− δ ceramics and to enhance densification and retard grain growth. The coefficient of thermal expansion of the SrCo 1− x Sb x O 3− δ ceramics increased with the content of the antimony ions, ranging from 10.17 to 15.37 ppm/°C at temperatures lower than the inflection point (ranging from 450 °C to 550 °C) and from 22.16 to 29.29 ppm/°C at higher temperatures. For the SrCo 0.98 Sb 0.02 O 3− δ ceramic, electrical conductivity reached a maximum of 507 S/cm at 450 °C. The ohmic and polarization resistances of the single cell with the pure SrCo 0.98 Sb 0.02 O 3−δ cathode at 700 °C read respectively 0.298 Ω cm 2 and 0.560 Ω cm 2 . The single cell with the SrCo 0.98 Sb 0.02 O 3− δ -SDC composite cathode appeared to reduce the impedances with the R 0 and R P at 700 °C reading respectively 0.109 Ω cm 2 and 0.127 Ω cm 2 . Without microstructure optimization and measured at 700 °C, the single cells with the pure SrCo 0.98 Sb 0.02 O 3− δ cathode and the SrCo 0.98 Sb 0.02 O 3− δ -SDC composite cathode, demonstrated maximum power densities of 0.100 W/cm 2 and 0.487 W/cm 2 . Apparently, SrCo 1− y Sb y O 3− δ is a potential cathode for use in IT-SOFCs.