Strontium and iron-doped barium cobaltite prepared by solution combustion synthesis: exploring a mixed-fuel approach for tailored intermediate temperature solid oxide fuel cell cathode materials

Abstract

Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3–d (BSCF) powders were prepared by solution combustion synthesis using single and double fuels. The effect of the fuel mixture on the main properties of this well-known solid oxide fuel cell cathode material with high oxygen ion and electronic conduction was investigated in detail. Results showed that the fuel mixture significantly affected the area-specific resistance of the BSCF cathode materials, by controlling the oxygen deficiency and stabilizing the Co 2? oxidation state. It was demonstrated that high fuel-to-metal cations molar ratios and high reducing power of the combustion fuel mixture are mainly responsible for the decreasing of the area-spe-cific resistance of BSCF cathode materials. Moreover, a new metastable monoclinic phase with Ba 0.5 Sr 0.5 CO 3 composition was discovered in the as-burned BSCF pow-ders, enlarging the existing information on the BSCF phase formation mechanism.