Influence of Ga-Ge doping on the structural and electrical properties of Li7La3Zr2O12 solid electrolytes

Abstract

In order to replace the conventional liquid electrolytes by solid electrolytes, high room temperature ionic conductivity is required. To achieve such high ionic conductivity, the series Li7-3xGaxLa3Zr1.9Ge0.1O12 was prepared by solid-state reaction method. The content of Ge was kept constant at 0.10 atoms per formula unit (a.p.f.u), and the Ga has been varied from 0 to 0.40 a.p.f.u. The conducting cubic phase was identified using X-ray diffraction study, whereas the physical and structural studies were performed using density measurements and scanning electron microscopy (SEM) analysis, respectively. Electrical conductivity results revealed that the 0.20 Ga ceramic sample possessed the highest room temperature Li ion conductivity of 5.09 × 10-4 S/cm with minimum activation energy of 0.25 eV. The high room temperature ionic conductivity makes the 0.20 Ga ceramic sample a suitable solid electrolyte for all-solid-state lithium-ion batteries (ASSLIBs).