Effects of B-site ion (Nb⁵⁺) substitution on the microstructure and ionic conductivity of Li_0.5La_0.5TiO₃ solid electrolytes

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 Li_0.5La_0.5TiO₃ 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.

Keywords:

• LLTO
• solid electrolyte
• ion substitution
• microstructure
• conductivity

Additional information

Funding

This work was financially supported by the Ministry of Science and Technology of China (MOST) (Grant No. 2013CB934700) and the Key Research and Development Project of Sichuan Province, China (Grant No. 2017GZ0396).