K. S. Chang, K. L. Tung, C. H. Kang, Y. C. Chiang, chung Yuan University, Chung LI, Taiwan
The zirconia-based solid electrolyte doped with various components of dopant was prepared using the atmospheric plasma spray (APS) system for the intermediate temperature solid oxide fuel cell (IT-SOFC) applications. The influence of spray parameters on the in-flight particle was analyzed by the Spray Watch diagnostic system for obtaining the optimized preparation conditions. The surface morphology, phase composition, ohmic resistance, ionic conductivity and activation energy were characterized using field emission scanning electronic microscopy (FE-SEM), X-ray diffraction (XRD) and AC impedance spectroscopy. For the further insight understanding, the positron annihilation spectroscopy (PAS) and molecular dynamic (MD) technique were adopted to analyzed the micro-defect and ionic transport mechanism in a microscopic scale.
Summary: The intermediate-temperature solid electrolyte for solid electrolyte was successfully prepared using the APS system. The plasma gun rate put a major factor that controlled the in-flight particle properties and later change the phase composition and surface morphology of coating layer by the XRD and SEM analyses. The gas mobility, structure stability and free space in the coating layer were strongly affected by the dopant composition, Sc2O3 and Y2O3 concentration by the MD and PAS results. PAS technique and MD simulation proved that themselves as well method for the micro-scale analyses
