Enhanced ionic conductivity of titanium doped Li7La3Zr2O12 solid electrolyte

Abstract Solid electrolyte Li 7 La 3 Zr 2- x Ti x O 12 ( x  = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) ceramics have been prepared via a conventional solid-state reaction. X-ray diffraction (XRD) analysis confirms that all samples formed a single phase with cubic garnet structure within the limit of instrument measurement, and with increasing Ti content from x  = 0 to 0.5, the intensity of diffraction peaks exhibits a tendency of weakening. It is found that Ti doping in Li 7 La 3 Zr 2 O 12 (LLZ) can lead to the increase of the densification, which is favorable to improve the ionic conductivity. Finally, optimized conductivity has been obtained for the sample with x  = 0.3 for lithium ion battery: the total ionic conductivity reaches a maximum of about 4.16 × 10 −4  S cm −1 at 30 °C with an activation energy of about 0.48 eV. XRD analysis and cyclic voltammetry experiments on cells indicate the Li 7 La 3 Zr 2- x Ti x O 12 pellet is stable with lithium metal.