Garnet Solid Electrolyte Composition for Higher Li+ Conductivity

The patent uses composite materials by combining garnet-type composite metal oxide (LLZGO) with secondary phases (LiF, BaZrO3, YF3, SrF2, or ScF3). This composite structure maintains the high safety characteristics of solid electrolytes while the specific phase composition and interface structure enhance lithium ion conductivity, resolving the contradiction between safety and ionic conductivity.

The invention applies local quality by creating specific phase distributions and interface structures within the solid electrolyte. The secondary phases are strategically positioned to form conductive pathways at grain boundaries and interfaces, locally enhancing ionic conductivity without compromising the overall safety properties of the bulk material.

The patent applies preliminary action by performing mechanochemical treatment on raw material powders before sintering. This pre-treatment step pre-mixes the lithium source, lanthanum source, zirconium source, gallium source, and reaction aid at the powder level, ensuring homogeneous distribution of Ga atoms in the final LLZGO phase. This preliminary mixing simplifies the subsequent sintering process and reduces manufacturing complexity despite the chemical substitution required.

The invention uses a reaction aid as an intermediary substance during the synthesis process. The reaction aid facilitates the mechanochemical treatment and sintering processes, enabling Ga substitution to occur uniformly during heating while maintaining process simplicity. The reaction aid mediates between the raw materials and the final product, making the Ga-substitution process more controllable and less complex.

The patent applies self-service through the mechanochemical treatment process where the reaction aid and raw materials undergo chemical reactions during the mechanical grinding process itself. The mechanical energy input triggers chemical reactions that form the desired phases in-situ during mixing, eliminating the need for separate chemical treatment steps. This self-service approach improves synthesis efficiency while keeping the overall process relatively simple.

The invention utilizes parameter changes by controlling the sintering temperature range (1100-1350°C) and time (10-30 hours) to optimize the formation of LLZGO phase with Ga substitution. By carefully adjusting these thermal parameters after mechanochemical treatment, the process achieves high synthesis efficiency for the desired phase structure. The specific parameter ranges enable complete reaction and phase formation without requiring additional complex processing steps.