摘要
Garnet-like Li6.8La3Zr1.8Bi0.2O12 （LLZBO） ＋ x mol.% Al2O3 （x = 0, 1.25, 2.50） lithium ionic electrolytes were prepared by conventional solid state reaction method under two different sintering temperatures of 1000℃ and 1100℃. XPS, induced coupled plasma optical emission spectrometer （ICP-OES）, XRD and AC impedance spectroscopy were applied to investigate the bismuth valance, lithium concentration, phase structure and lithium ionic conductivity, respectively. Electrical measurement demonstrated that ionic conductivity of AI-added LLZBO compounds could be obviously improved when the sample sintering temperature increased from 1000℃ to 1100℃. The highest ionic conductivity 6.3×10-S/cm was obtained in the LLZBO-1.25%AI sample sintered at 1100℃, in consistent with the lowest activation energy 0.45eV for the lithium ion migration. The mechanism related with good ionic conductivity in the AI-added LLZBO sample was attributed to the lattice distortion induced by the partial AI substitution at Zr sites, which is helpful to improve the migration ability of Li ions in lattice.
Garnet-like Li6.8La3Zr1.8Bi0.2O12 （LLZBO） ＋ x mol.% Al2O3 （x = 0, 1.25, 2.50） lithium ionic electrolytes were prepared by conventional solid state reaction method under two different sintering temperatures of 1000℃ and 1100℃. XPS, induced coupled plasma optical emission spectrometer （ICP-OES）, XRD and AC impedance spectroscopy were applied to investigate the bismuth valance, lithium concentration, phase structure and lithium ionic conductivity, respectively. Electrical measurement demonstrated that ionic conductivity of AI-added LLZBO compounds could be obviously improved when the sample sintering temperature increased from 1000℃ to 1100℃. The highest ionic conductivity 6.3×10-S/cm was obtained in the LLZBO-1.25%AI sample sintered at 1100℃, in consistent with the lowest activation energy 0.45eV for the lithium ion migration. The mechanism related with good ionic conductivity in the AI-added LLZBO sample was attributed to the lattice distortion induced by the partial AI substitution at Zr sites, which is helpful to improve the migration ability of Li ions in lattice.
基金
Acknowledgements This work was financially supported by the National Natural Science Foundation of China （Grant Nos. 11374299, 11405203 and 51401203）.
