Study of Ge-doped garnet type Li7La3Zr2O12 as solid electrolyte for Li-ion battery application

The series Li7-4xGexLa3Zr2O12 has been synthesized using conventional solid-state reaction method by substituting Germanium (Ge) at the Li site with the varying content of Ge (x) from 0.05 to 0.20. The conducting cubic phase is confirmed using XRD analysis. The surface morphology and elemental distribution have been studied with the help of SEM characterization. The densities of the samples were calculated. For the confirmation of functional groups present, IR spectroscopy has been studied. The modulus and ac conductivity studies have also been examined. A complex impedance study has been carried out in the frequency range 20 Hz to 20 MHz .The highest ionic conductivity has been observed for 0.10 Ge. The minimum activation energy of 0.56 eV is associated with the highest conductivity value of 7.23 x 10(-6) S/cm at room temperature. The increment in ionic conductivity by one order at room temperature makes 0.10 Ge containing ceramic sample a promising candidate as a solid electrolyte.