A Versatile Li6.5In0.25P0.75S5I Sulfide Electrolyte Triggered by Ultimate-Energy Mechanical Alloying for All-Solid-State Lithium Metal Batteries

Sulfide solid electrolytes (SSEs) have captured plentiful interest on account of their high ionic conductivity and appropriate mechanical strength. However, the poor air stability and cost-intensive preparation process of SSEs limit their applications. Herein, a novel ultimate-energy mechanical alloying (UEMA) approach is applied to rapidly synthesize the argyrodite-type electrolytes in a one-pot process. According to the hard-soft-acid-base theory and the first-principles density functional theory (DFT) calculation, In-doping in Li6PS5I is attempted to enhance air stability and the experimental results demonstrate the success of this approach. The synthesized Li6.5In0.25P0.75S5I electrolyte has a high ionic conductivity (1.06 mS cm(-1)), and also presents excellent interfacial stability against Li metal, benefiting from the formation of a LiI-rich interphase layer. The assembled Li-S battery with Li6.5In0.25P0.75S5I as an interlayer delivers a high discharge capacity (954 mAh g(-1)) and presents the capacity retention of 96% after 200 cycles. The In-doped Li6PS5I is a novel promising electrolyte with high air stability and ionic conductivity for the application of all-solid-state lithium metal batteries.

Automated summary

Novel Ultimate-Energy Mechanical Alloying (UEMA) approach was successfully applied to rapidly synthesize high ionic conductivity and air-stable Argyrodite-type electrolyte Li6.5In0.25P0.75S5I for potential applications in all-solid-state lithium metal batteries.