Composite electrolytes ceramic Li₇La₃Zr₂O₁₂/glassy Li₂O-Y₂O₃-SiO₂

Highlights: • We synthesized Li₇La₃Zr₂O₁₂-x wt% 40.2Li₂O·5.7Y₂O₃·54.1SiO₂ (x = 1–10) composites. • Density of the composite samples is higher than one of the sintered Li₇La₃Zr₂O₁₂. • The composition with x = 5 has high total conductivity, 2.5 × 10⁻⁵ S cm⁻¹ at 25 °C. - Abstract: We have investigated the effect of lithium yttrium-silicate glass 40.2Li₂O·5.7Y₂O₃·54.1SiO₂ on the density and total conductivity of tetragonal Li₇La₃Zr₂O₁₂. An optimal sintering temperature (1200 °C) was selected on the basis of a composite with 1 wt% of the glass having the highest density and total conductivity after annealing at this temperature. A series of composites Li₇La₃Zr₂O₁₂-x wt% 40.2Li₂O·5.7Y₂O₃·54.1SiO₂ (x = 1–10) was prepared. The samples were characterized by X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. The data revealed that the sintering additive interacted with Li₇La₃Zr₂O₁₂, causing the glass to crystallize during annealing. The conductivity of the composites was studied using complex impedance spectroscopy over a temperature range of 20–250 °C. The composite with x = 5 exhibited the highest total conductivity at room temperature: 2.5 × 10⁻⁵ S cm⁻¹.