Solid state synthesis of extra phase-pure Li4Ti5O12 spinel

Abstract

Extra phase-pure Li4Ti5O12 spinel with particle sizes less than 500 nm was synthesized by solid state reaction of mechanochemicaly activated mixture of nano anatase and Li2CO3 for a very short annealing time, 4 h at 800°C. Structural and microstructural properties, the mechanism of solid state reaction between anatase and Li2CO3 as well as thermal stability of prepared spinel were investigated using XRPD, SEM and TG/DSC analysis. The mechanism of reaction implies decomposition of Li2CO3 below 250ºC, formation of monoclinic Li2TiO3 as intermediate product between 400 and 600°C and its transformation to Li4Ti5O12 between 600-800ºC. The spinel structure is stable up to 1000ºC when it is decomposed due to Li2O evaporation.