Synthesis and Study of Conductivity of Al-Substituted Li7La3Zr2O12

Abstract

The method of solid-phase sintering was used to synthesize samples of lithium-conducting Li_6.4Al_0.2La₃Zr₂O₁₂ solid electrolyte with a garnet structure. Higher technological efficiency of the method of synthesis was achieved owing to using low-melting nitrate crystalline hydrates of ZrO(NO₃)₂ · 2H₂O and La(NO₃)₃ · 6H₂O as initial substances: formation of the melt considerably intensified the interaction, caused a decrease in the duration and energy consumption of the method, and provided the presence of only a single phase of powdered solid electrolyte with a high Li-ion conductivity. The excess of the lithium-containing component (Li₂CO₃) in the mix was varied to compensate lithium losses in the course of the high-temperature treatment. Specific ionic conductivity of Li_6.4Al_0.2La₃Zr₂O₁₂ was determined using the impedance spectroscopy technique and was 2 × 10^–4 S/cm at the room temperature.