SnO2/TiO2共掺杂氧化钽基固体电解质的制备和性能研究

Preparation and Properties of SnO/TiO Co-doped Tantalum Oxide Based Solid Electrolytes

采用草酸盐共沉淀法制备出具有三斜结构的共掺杂固体电解质Ta1-x-yTixSnyO2.5-δ(x=0.077,y=0~0.053)材料。利用X射线衍射分析、扫描电子显微镜、差热分析、阻抗分析等方法对该固体电解质进行了热性能和电性能分析,研究发现经Sn^4+和Ti^4+共掺杂之后,将氧化钽基电解质的高温三斜相稳定到了室温,在其结构中因掺杂产生更多氧空位从而提高了氧化钽基电解质的电导率。在973 K条件下,固体电解质Ta0.89Ti0.077Sn0.033O2.5-δ的离子电导率为0.76×10^-1 S/cm,活化能为0.696 eV,同时该共掺杂固体电解质具有较低的热膨胀系数3.78×10^-6 K^-1,属于低膨胀材料,具有良好的热稳定性和热循环性能。

The co-doped solid electrolyte Ta1-x-yTixSnyO2.5-δ(x=0.077,y=0-0.053) material with triclinic structure was prepared by oxalate coprecipitation method. The thermal and electrical properties of the solid electrolyte were analyzed by X-ray diffraction analysis(XRD), Scanning electron microscope(SEM), Differential thermal analysis(DTA), Electrochemical impedance spectroscopy analysis(EIS). The study found that after co-doping with Sn^4+/Ti^4+, the high temperature triclinic phase of tantalum oxide-based electrolyte was stabilized to room temperature, and more oxygen vacancies were generated due to doping in its structure, thus improving the conductivity of tantalum oxide-based electrolyte. At working temperature of 973 K, the solid electrolyte Ta0.89Ti0.077Sn0.033O2.5-δ has an ion conductivity of 0.76×10^-1 S/cm and activation energy of 0.696 eV. The co-doped solid electrolyte has a low thermal expansion coefficient of 3.78×10^-6 K^-1, which is a low-expansion material, and the solid electrolyte has good thermal stability.