A simple preparation process of lithium titanium aluminum phosphate solid electrolyte with ultra-high ionic conductivity

Lithium Aluminum Titanium Phosphate (LATP) solid electrolyte has many advantages such as high ionic conductivity, good air stability, and low raw material cost, which has great potential for industrial development. However, the existing preparation process still can not meet the needs of industrialization well. We propose a novel simple solid-liquid mixing process to prepare LATP. By optimizing the reactants and adopting the "vacuum self-mixing" process, in the case of removing the mixing step, a high-performance LATP solid electrolyte with high purity is also obtained, the total ionic conductivity of the which at room temperature is as high as 1.7 ​mS/cm, the bulk conductivity is as high as 7.2 ​mS/cm, both reaching the highest value in published literature, the obtained sheet density is also as high as 99.4%. The process also avoids the problems of material sticking to the pot and low sintering yield in the traditional sintering process, which will provide a more convenient technological route for the industrialization of LATP solid electrolyte. The introduction of highly active raw materials not only eliminates the mixing step, but also the conductivity of the obtained LATP electrolyte reaches the highest value since reports. [Display omitted] •A novel method was used to prepare a high-purity LATP solid electrolyte.•High-purity LATP phase was still obtained under the non-mixing process.•The bulk ionic conductivity at room temperature reached 7.2 ​mS/cm.•The total ion conductivity at room temperature reached 1.7 ​mS/cm.•The ionic conductivity have reached the highest value reported in public.