Facile synthesis and electrochemical properties of high lithium ionic conductivity Li1.7Al0.3Ti1.7Si0.4P2.6O12 ceramic solid electrolyte

Abstract The solid state electrolytes based on NASICON structure are widely researched for high-energy solid-state lithium batteries due to its non-flammability, high conductivity, wide electrochemical window and easy process ability. In this paper, Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 (x = 0.3 and y = 0.4) ceramic electrolyte has been successfully synthesized by the solution-based method at calcining temperature as low as 650 °C. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and electrochemical impedance spectroscopy (EIS). The effect of preparation conditions on the morphology, crystallinity and ionic conductivity of Li 1.7 Al 0.3 Ti 1.7 Si 0.4 P 2.6 O 12 have been studied in detail. The results showed that the Li 1.7 Al 0.3 Ti 1.7 Si 0.4 P 2.6 O 12 powders have rhombohedral NASICON-type structure, and the Li 1.7 Al 0.3 Ti 1.7 Si 0.4 P 2.6 O 12 pellet sintered at 1000 °C for 6 h exhibits the highest total lithium-ion conductivity (1.33 × 10 −3  S cm -1  at room temperature) and the lowest activate energy (0.25 eV). Therefore, the solution-based method will be a significant route for the industrialization preparation of Li 1.7 Al 0.3 Ti 1.7 Si 0.4 P 2.6 O 12 .