Instantaneous preparation of high lithium-ion conducting sulfide solid electrolyte Li7P3S11 by a liquid phase process

Abstract

A solid electrolyte with a small particle size, good mechanical properties and high ionic conductivity is required to achieve high energy and power density in the all-solid-state battery. Here, we report an instantaneous preparation of high lithium-ion conducting sulfide solid electrolyte Li₇P₃S₁₁ by a simple procedure involving a liquid phase process under ultrasonic irradiation and low thermal treatment at 220 °C. A short reaction time of 30 min was enough to produce the formation of PS₄³⁻ units. Subsequent drying and heating processes led to the precipitation of the Li₇P₃S₁₁ phase with a particle size below 500 nm, achieving high ionic conductivity of 1.0 × 10⁻³ S cm⁻¹ at 22 °C and a low activation energy of 12.8 kJ mol⁻¹.