Аннотация
The article provides a comparative assessment of the structural and electrochemical properties of lithium aluminum titanium phosphate (LATP) solid electrolytes with different lithium contents LATP (Li1.3-1.5AlxTi2-x(PO4)3). LATP polycrystals with NASICON-type structure were synthesized by the molten flux method, which included mixing LiNO3, Al2O3, TiO2, NH4H2PO4 and CO(NH2)2 precursors, followed by staged heating at 170°C, 500°C, and 800°C, pressing, and final sintering at 800°C for 4 hours. X-ray diffraction analysis confirmed the formation of the main LATP crystalline phase, while an increase in lithium concentration led to the appearance of secondary phases such as Li4P2O7, AlPO4, and TiP2O7, which affected ionic conductivity. Electrochemical impedance spectroscopy showed that LATP (Li1.4) exhibits the highest ionic conductivity (1.66-1.85 × 10-4 S/cm at 25°C) compared to Li1.3 and Li1.5 samples due to its higher structural density and optimal phase composition. The temperature dependence analysis revealed that increasing temperature enhances lithium-ion mobility, confirming thermally activated ion transport. Therefore, the Li1.4Al0.4Ti1.6(PO4)3 composition demonstrates the most promising characteristics as a solid electrolyte for all-solid-state lithium batteries.