Effects of <i>B</i>-site ion (Nb<sup>5+</sup>) substitution on the microstructure and ionic conductivity of Li<sub>0.5</sub>La<sub>0.5</sub>TiO<sub>3</sub> solid electrolytes
Yue Jiang, Yi Huang, Zhiwei Hu, Yuxi Zhou, Jiliang Zhu, Xiaohong Zhu
Abstract
Nb-doped lithium lanthanum titanate (LLTO) ceramic electrolytes were fabricated by the conventional solid-state reaction method. Effects of Nb5+ substitution on the microstructure and ionic conductivity of LLTO were investigated systematically. It is found that the 4 at.% Nb-doped Li0.5La0.5TiO3 sintered at 1350 °C for 12 h shows the minimum amount of pores in microstructure and the highest total conductivity, 1.04 × 10−4 S/cm, being 1.6 times of that without Nb addition. Therefore, it is proved experimentally that a proper amount of Nb doping could be an effective and facile approach to improve the LLTO’s microstructure and total conductivity, thus making Nb-doped LLTO a good solid electrolyte candidate for use in lithium-ion batteries.