A Novel Sol-Gel Method for Large-Scale Production of Nanopowders: Preparation of Li $_{1.5}$ Al $_{0.5}$ Ti $_{1.5}$ (PO $_{4}$ ) $_{3}$ as an Example

Sol–gel synthesis is an extensively used method for the preparation of nanopowders. However, complicated or expensive precursors, and the necessity of using organic solvent and/or heat assistance limit the method to laboratory-scaled level. An aqueous-based sol–gel method with spontaneous sol and gel formation is developed in this study. It can be applied on a large scale to synthesize compounds with Ti4+ and PO43− as major components with low cost. Al-substituted LiTi2(PO4)3 (LATP) has been widely investigated as a promising candidate for solid electrolyte in Li-ion or Li-air batteries. Major challenges such as unsatisfactory phase purity, low sintering activity, and high production costs are faced during the fabrication of LATP. In this study, as a sample application, Li1.5Al0.5Ti1.5(PO4)3 (LATP05) is conveniently prepared on a large scale by the novel sol–gel method with high phase purity, active densification behavior and high conductivity