Synthesis and Characterization of Ba_0.96Sr_0.04Ce_0.7Zr_0.3O₃ Solid Oxide Fuel Cell Electrolyte by Citrate EDTA Complexing Sol-Gel Process

Abstract

Abstract. This paper reports on the effect of Strontium doping on BaCe 0.7 Zr 0.3 O 3 electrolyte prepared using the citrate-EDTA complexing sol-gel process at temperature T=1000°C. The phase formation and evolution with the temperature has been studied by X-ray diffraction (XRD), thermal analysis (TG-DTA). The morphology of the sintered powder at T=1300°C is examined by SEMScanning Electron Microscopy, EDAX -Energy-dispersive X-ray spectroscopy analysis, FTIR -Fourier transforms infrared spectrometer, FTRS -Raman measurements. The crystallite size of the ceramic powders calculated from Scherrer equation is 28nm and the diffraction peak shifted to higher angles. Microstructure of the sintered powder revealed that the average grain size is in the range of 2 m. The incorporation of Sr is found to suppress the formation of CeO 2 like second phase and enhance the grain growth in sintered oxides. Dense ceramic materials were obtained at 1300°C and the relative density is 80% of the theoretical density. FTIR and Raman measurements reveal the complete single phase formation of the orthorhombic perovskite structure. The ionic conductivity of the pellet is investigated from room temperature to 400°C and is found to be 1.1x10 -4 S/cm (400°C). The conductivity increased as temperature increases with an activation energy of 0.48eV and hence this composition qualifies to be a promising electrolyte.

Theoretical investigation of structural, electronic, dielectric and optical characteristics of cubic perovskite BaCeO3

“…BaCeO 3 perovskite is especially important since it could have relatively high proton and hole conductivity at high temperatures [6,7]. The crystal structure of BaCeO 3 changes with temperature in three steps [8]: orthorhombic Pmcn -orthorhombic Incn -rhombohedral F32/n -cubic Pm3m at transitional temperatures 563, 673 and 1173 K, respectively [9,10]. Studies of the use of differently doped barium cerates in a fuel cell are well conducted and relate the properties with their stability and transport mechanisms.…”