液相法によるリチウムイオン伝導性酸化物の低温合成

采用溶胶-凝胶法在低温下制备了锂石榴石类氧化物Li7-xLa3Zr2-xNbxO12(LLZNbO，x=0-1)。采用LiO_2-B_2O_3-SiO_2玻璃和BaO-B_2O_3-SiO_2玻璃添加剂促进陶瓷电解液在低温下保持立方相稳定的烧结。53LiO_2·31B_2O_3·12SiO_2(摩尔%)(LiO_2-B_2O_3-SiO_2玻璃)或35BaO·10CaO·5Al_2O_3·15B_2O_3·10SiO_2(摩尔%)(BaO-B_2O_3-SiO_2玻璃)被压制成球团，在900℃下烧结，加入玻璃添加剂后，相对密度达到86%。而用LiO_2-B_2O_3-SiO_2玻璃烧成的复合材料为单一立方相，加入4%的LiO_2-B_2O_3-SiO_2玻璃，30℃时的离子电导率为8×10~(-5)S/cm。该材料的电导率比报道的固相反应材料低20%，但所采用的热处理工艺比传统的固相反应工艺所需的温度低约300℃。这为LLZNbO固体电解液在全固态电池中的进一步应用做出了重要贡献。

Lithium garnet-type oxides Li7-xLa3Zr2-xNbxO12 (LLZNbO, x=0-1) were prepared by a sol-gel process at low temperatures. Then, glass additives, LiO2-B2O3-SiO2 glass and BaO-B2O3-SiO2 glass, were used to stimulate the sintering of the ceramic electrolyte retaining the cubic phase stable at low temperatures.The cubic garnet phase was formed by a heat-treatment of sol-gel derived precursor powders at 600 - 700 degree C. The presursor powders and glass additives, 53LiO2･31B2O3･12SiO2 (mol%) (LiO2-B2O3-SiO2 glass) or 35BaO･10CaO･5Al2O3･15B2O3･10SiO2 (mol%) (BaO-B2O3-SiO2 glass) were pressed into pellets and sintered at 900 degree C.The relatative density of 86% was achieved by the sintering with glass additives at 900 degree C. In the composites sintered with the BaO-B2O3-SiO2 glass, the presence of La2Zr2O7 was detected at concentration higher of 4 wt%, while the single cubic phase was obtained for the composites sintered with the LiO2-B2O3-SiO2 glass.The ionic conductivity of the obtained composite was 8x10^-5 S/cm at 30 degree C using 4 wt.% of LiO2-B2O3-SiO2 glass. The conductivity is 20% lower than the material reported by the solid state reaction process, but the heat treatment used is about 300 degree C lower than that required by the conventional solid state reaction process. This represents an important contribution to further application of the LLZNbO solid electlolyte to all-solid-state battery.