Sol-gel synthesis and structural study of a lithium titanate phase Li _3xLa _2/3.x □_1/3-2x TiO₃ as solid electrolyte

Abstract

Perovskite lithium lanthanum titanate (LLTO) was prepared as an inorganic solid electrolyte material for lithium ion batteries applications using sol-gel method. Three different compositions of : (a) 3x=0.3 (Li 0.3La 0.57TiO3), (b) 3x=0.5 (Li 0.5La 0.5TiO3) were prepared and calcined at 1000°C for 6h, and (c) 3x=0.1 (Li 0.1La 0.63TiO3) prepared and calcined at 1100°C for 6h. The effects of lithium content and calcination temperature on the structure of the perovskite powders were studied. The synthesized powders were characterized by X-ray diffraction analysis. Results indicate that the Li 0.3La 0.57TiO3 was crystallized in tetragonal structure of space group P4/mmm. On the other hand, Rietveld refinement analysis for the LLTO samples confirmed the formation of the Li 0.3La 0.57TiO3 crystalline phase in the tetragonal P4/mmm space group, the Li 0.5La 0.5TiO3 phase in the tetragonal P4/mmm space group, and Li 0.1La 0.63TiO3 phase in orthorhombic Pmmm space group.