Determination of the non-Arrhenius behaviour of the bulk conductivity of fast ionic conductors LLTO at high temperature

Li3xLa2/3 − xTiO3 (where x = 0.08, 0.1, and 0.12) lithium ionic conductors were investigated by impedance spectroscopy in broad frequency and temperature ranges. Three relaxation processes, corresponding to lithium ion migration in the bulk and grain boundaries of the ceramics and electrode polarization, were observed in the impedance spectra. Temperature dependences of the bulk ionic conductivity of all the investigated ceramics show non-Arrhenius behaviour. The experimental data have also been analyzed by using the dielectric spectra and applying Cole–Cole function for data fitting. Several relaxations of Li+ ions in the bulk of LLTO ceramics have been found.