Synthesis of Ba_0.3Ca_0.7Co_0.8Fe_0.2O_3-δ composite material as novel catalytic cathode for ceria-carbonate electrolyte fuel cells

ABSTRACT This work reports a new composite Ba_xCa_1-xCo_yFe_1-yO_3-δ (BCCF) cathode material for advanced and low temperature solid oxide fuel cells (SOFCs). The BCCF-based composite material was synthesized by sol gel method and investigated as a catalytic cathode for low temperature (LT) SOFCs. XRD analysis of the as-prepared material revealed the dominating BCCF perovskite structure as the main phase accompanied with cobalt and calcium oxides as the secondary phases resulting into an overall composite structure. Structure and morphology of the sample was observed by Field Emission Scanning Electron Microscope (FE-SEM). In particular, the Ba_0.3Ca_0.7Co_0.8Fe_0.2O_3-δ (BCCF37) showed a maximum conductivity of 143 S cm^-1 in air at 550 °C measured by DC 4 probe method. The BCCF at the optimized composition exhibited much higher electrical conductivities than the commercial Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) perovskite cathode material. A maximum power density of 325 mW cm^-2 at 550 °C is achieved for the ceria-carbonate electrolyte fuel cell with BCCF37 as the cathode material.