Enhanced ionic conductivity of titanium doped Li7La3Zr2O12 solid electrolyte

Solid electrolyte Li7La3Zr2-xTixO12 (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 Li7La3Zr2O12 (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 Li7La3Zr2-xTixO12 pellet is stable with lithium metal.