Nano Ysz Powder Preparation And Characterization Of Hot Water

With the development of energy shortage, a new using technology of green energy-Full Cell, is now gradually developing. It is a device which can transform chemical energy of the fuel into electric energy by electrochemical reaction. So, fuel cells have many advantage such as cleanness, high-efficiency, environment-friendly, etc. The study of solid oxide fuel cell(SOFC) is the most widely and has good development prospect. Yttria stabilized zirconia(YSZ) has excellent chemical and mechanical properties, thermal stability, pure oxygen conduction, and now it still has great potential as electrolyte materials in medium-high temperature SOFC(700-1000℃). Now the study of the film forming technology of YSZ gradually becomes an important direction in promoting the industrialization and practicality of SOFC. In the process of fabrication thin film of SOFC, many of these are based on the preparation of YSZ powder. Some study show that the ionic conductivity and mechanical of the YSZ film are related with the characteristics of the powder, which require the powder possessing small grain size, narrow particle size distribution, particle uniformity and less reunion. Therefore, studying the preparation of YSZ having excellent properties becomes research focus.In view of this background, the paper mainly studies the optimization of the preparation process about YSZ. The method is coprecipitation-two step hydrothermal. And using X-ray diffraction(XRD), transmission electron microscopy(TEM), scanning electron microscope(SEM), infrared spectrum analysis(FT-IR), particle siza testing analysis etc.The chapter3of the paper prepared cubic phase YSZ which had good dispersion and the particle size were about6nm by artificial dropping method. Compared with one step hydrothermal, the two step hydrothermal had more smaller particle size about6nm, better dispersion, complete morphology and uniform size. Also we optimized the parameters of nanopowder YSZ, and individual analysis each factor in effects of phase and morphology of YSZ. The optimized process was as follows: cation concentration was0.05mol/L, the pH value was12, selected ethanol as dispersant and1:1deionized water as mother liquor, selected K2CO3/KOH(molar ratio1:1) as composite mineralizer, hydrothermal temperature was200℃, hydrothermal time was24h. Under the control of these factors, the powder was pure cubic phase, complete morphology of the particle and good dispersion.The chapter4of the paper optimized the preparation of YSZ by hydrothermal based on the chapter3. With pump-inlet type titration the experiment obtained pure cubic phase YSZ, which had good dispersion and complete particle morphology. Compared with artificial dropping method, the pump-inlet type titration realized small scale automation and saved some human and material resources, also obtained more large powder. Then we optimized the parameters of nanopowder YSZ by the pump-inlet type titration and had optimum process as follows:optimum reaction time was8h, optimum stirring speed was900r/min, optimum pump-inlet speed was0.5/1.5, optimum reaction temperature was70℃, optimum aging time was12h. Under the control of these factors, the powder was pure cubic phase, complete morphology of the particle and good dispersion.