Evolution of the sintering ability, microstructure, and cell performance of Ba_0.8Sr_0.2Ce_0.8-x-yZr_yIn_xY_0.2O_3-δ (x = 0.05, 0.1 y = 0, 0.1) proton-conducting electrolytes for solid oxide fuel cell

Ba_0.8Sr_0.2Ce_0.8-x-yZr_yIn_xY_0.2O_3-δ (x = 0.05, 0.1 y = 0, 0.1) proton-conducting oxides are prepared using a solid state reaction process. The effect of indium contents on the microstructures, chemical stability, electrical conductivity, and sintering ability of these Ba_0.8Sr_0.2Ce_0.8-x-yZr_yIn_xY_0.2O_3-δ oxides were systemically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and two probe conductivity analysis. The results reveal that the Ba_0.8Sr_0.2Ce_0.8-x-yZr_yIn_xY_0.2O_3-δ oxides are cubic perovskite crystal structure without second phase. Surface morphology of 1450°C, 4 h sintered oxides shows a dense microstructure. The optimum conductivity of Ba_0.8Sr_0.2Ce_0.8-x-yZr_yIn_xY_0.2O_3-δ oxide is 0.011 S/cm measured at 800°C. Chemical stability of the oxides to resist CO2 at 600°C is effectively improved by doping 0.1 at%indium or more. In addition, the laminated electrolyte and anode layers which fabricated by tape casting were co-sintered at 1450°C for 4 h. The sintered half-cell coated with Pt paste as cathode was used for IV curve performance testing. The performance of the single cell of anode supported protonsolid oxide fuel cell (P+-SOFC) have powder density of 139.8mW/cm at 800°C. Therefore, the Ba_0.8Sr_0.2Ce_0.8-x-yZr_yIn_xY_0.2O_3-δ ceramic is suggested to be a potential electrolyte material for P+-SOFC applications.