Insights into the Effects of Co-Regulated Factors on Li_1.3Al_0.3Ti_1.7(PO₄)₃ Solid Electrolyte Preparation: Sources, Calcination Temperatures, and Sintering Temperatures

Abstract

The ionic conductivity, phase components, and microstructures of LATP depend on its synthesis process. However, their relative importance and their interactions with synthesis process parameters (such as source materials, calcination temperature, and sintering temperature) remain unclear. In this work, different source materials were used to prepare LATP via the solid-state reaction method under different calcination and sintering temperatures, and an analysis via orthogonal experiments and machine learning was used to systematically study the effects of the process parameters. Sintering temperatures had the greatest effect on the total ionic conductivity of LATP pellets, followed by the sources and calcination temperatures. Sources, as the foundational factors, directly determine the composition of a major secondary phase of LATP pellets, which influences the whole process. The calcination temperature had limited impact on the ion conductivity of LATP pellets if pellets were sintered under the optimal temperature. The sintering temperature is the most important factor that influences the ion conductivity by eliminating most secondary phases and altering the microstructure of LATP, including the intergranular contact, grain size, relative densities, etc. This work offers a novel perspective to comprehend the synthesis of solid-state electrolytes beyond LATP.

Facile Route to Synthesize a Highly Sinterable Li1.3Al0.3Ti1.7(PO4)3 Solid Electrolyte

“…Through the control of the second phase combined with the functional characteristics of the LATP amorphous phase, the high sinterability LATP electrolyte can be realized. According to our recent work, the second phase of LATP are significantly related to raw sources; moreover, TiO 2 generated during the reaction is regarded as the effectively nucleating agent during LATP preparation and affected LATP crystallinity, which also was influenced by the choice of raw materials, especially Ti sources. Herein, we report a facile synthetic route using traditional solid-state approaches for LATP solid electrolytes with high sinterability and high ionic conductivity only by Ti source optimization, which does not require complex sintering techniques, sintering additives, or doping elements.…”