Solvent-assisted ball milling for synthesizing solid electrolyte Li7P3S11

Solvent-assisted ball milling is used to prepare the sulfide solid electrolyte Li 7 P 3 S 11 . Comparing with dry ball milling and simple liquid phase synthesis, solvent-assisted ball milling can significantly promote the reaction of the starting materials from tens of hours to only several hours. When using dimethoxyethane as the assistant solvent, relatively pure Li 7 P 3 S 11 with ionic conductivity of 1.0 × 10 −4 S/cm can be synthesized after 8-hour ball milling with following 2-hour 180°C vacuum drying and 4-hour 230°C heat treatment. It is revealed that the transition from the precursor to Li 7 P 3 S 11 is a two-step process, with an intermediate composed of a thio-LISICON III analogous phase and an amorphous phase. This work not only provides a synthesis route of Li 7 P 3 S 11 which reduces synthesis duration, but also offers an instructive insight into the phase evolution in solvent-based synthesis process of sulfide solid electrolytes.