Phase formation of a garnet-type lithium-ion conductor Li7 - 3xAlxLa3Zr2O12
Phase formation of a garnet-type lithium-ion conductor Li7 - 3xAlxLa3Zr2O12
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DOI：
10.1016/j.ssi.2015.04.011
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发表时间：
2015-09-01
影响因子：
3.2
通讯作者：
Imanishi, Nobuyuki
中科院分区：
文献类型：
--
作者：
Matsuda, Yasuaki;Sakamoto, Kimie;Imanishi, Nobuyuki
采用高温X射线衍射方法研究了Li 7 - 3xAlxLa 3 Zr 2 O 12的相形成过程。在室温下，在x = 0至0.20的范围内获得了四方相，并且在x = 0.25时形成了立方相。晶格常数在x = 0 ~ 0.20范围内呈线性变化，这与系统组成的变化相一致。Al ~（3+）的溶解度极限为x = 0.25。对于x = 0，在640 ° C下观察到四方相和立方相之间的可逆相变。在相变温度下离子电导率的显著增加与锂离子有序/无序的结构变化相一致。此外，相变温度随着x的增加而降低，并且立方相从室温到900 ℃稳定在x = 0.25。离子电导率随x的增加而增加，当x = 0.25时，在25 ℃下获得的最高离子电导率为3.1 x 10（-4）S cm（-1）。Al ~（3+）取代引入了锂空位，对四方相和立方相之间的相变有很大影响。结果表明，控制锂空位是获得快速锂导电相的关键。(C)2015 Elsevier B. V.版权所有。
The phase formation of Li7 - 3xAlxLa3Zr2O12 was investigated by high temperature X-ray diffraction measurements. The tetragonal phase was obtained in the range of x = 0 to 0.20 and the cubic phase was formed at x = 0.25 at room temperature. A linear change of the lattice parameters was observed from x = 0 to 0.20, which is in good agreement with the systematic composition change. The solubility limit of Al3+ was determined to be x = 0.25. The reversible phase transition between the tetragonal phase and the cubic phase was observed at 640 degrees C for x = 0. The marked increase of ionic conductivity at the phase transition temperature is consistent with the structural change of the ordering/disordering of lithium ions. In addition, the phase transition temperature decreased with increasing x, and the cubic phase was stabilized at x = 0.25 from room temperature to 900 degrees C. The ionic conductivity increased with x and the highest ionic conductivity of 3.1 x 10(-4) S cm(-1) at 25 degrees C was obtained for x = 0.25. Al3+ substitution introduces lithium vacancies, which has a strong influence on the phase transition between the tetragonal and cubic phases. The results obtained here suggest that control of the lithium vacancies is the key to obtain a fast lithium-conducting phase. (C) 2015 Elsevier B.V. All rights reserved.