Summary: | 碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 98 === The aim of this study was to develop bismuth-based solid electrolytes with high ionic conductivity for intermediate temperature (500~800oC) SOFC (solid oxide fuel cell) instead of conventional YSZ electrolytes showing very low ionic conductivity during 500~800oC.
In this study, a series of Bi1-XNbxO1.5+δ powders were fabricated hydrothermally by altering the mineralizers, reaction temperature and holding time. The precursor of bismuth nitrate and niobium oxide were fabricated nano size Bi1-XNbXO1.5+δ powders.
The specimen were characterized by X-ray diffraction、scanning electron microscopy、 electrical conductivity. The morphology were spherical, can effectively control the powders morphology and mean powder size were 80~100 nm. Analysis of Bi3NbO7 cubic fluorite structure by XRD. Bi0.79Nb0.21O1.5+δ powders into dense pellets at sintered temperature 800oC/2 h, Bi0.79Nb0.21O1.5+δ had the highest conductivity by DC 4-wire resistance measurement. The conductivity was 0.35 Scm-1 at 800oC.
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