Structural, thermal properties and improved ionic conductivity of cerium-doped Li0.5+xLa0.5-xCe2xTi1-xO3 solid electrolyte materials

A series of Ce-doped Li0.5+xLa0.5-xCe2xTi1-xO3(x = 0.0, 0.025, and 0.05) ionic conductive crystalline oxides were produced by a solid-state reaction process. The effect of Ce-doping on the thermal, structural, electrical, and dielectric characteristics of Li0.5La0.5TiO3 was investigated using TGA/DTA, XRD, SEM/EDS, FT-IR spectroscopy, and impedance spectroscopy techniques. The TGA/DTA spectra confirmed the phase transformation and weight loss of the mixed precursors. The XRD and FT-IR analysis revealed that the materials exhibited a cubic system with a perovskite phase, which corresponds to the Pm3m space group. The EDS analysis clearly detected the presence of all elements except Li in the Li0.5+xLa0.5-xCe2xTi1-xO3 materials. The electrical conductivities were found to be 3.9 x 10-5 S/cm for Li0.525La0.475Ce0.05Ti0.975O3, and 3.1 x 10-5 S/cm for Li0.55La0.45Ce0.1Ti0.95O3, which are higher than that of Li0.5La0.5TiO3 (1.7 x 10-5 S/cm). This confirmed that the incorporation of a small quantity of Ce4+ ions can enhance the electrical conductivity of Li0.5La0.5TiO3 sample.