Liquid-Assisted Mechanochemical Synthesis of LiI-Doped Sulfide Glass Electrolyte

Inorganic solid electrolytes (ISEs) gain tremendous attention during the past decade for application in energy storage. Among different classes of ISEs, sulfides are particularly appealing due to their higher ionic conductivity, ductility, and lower density compared with oxides. However, most of the preparation methods proposed so far require either the time-consuming mechanical ball-milling process or the energy-consuming high-temperature solid-state reaction. Herein, a new and fast liquid-assisted approach to synthesize LiI-doped glassy Li$_{2}$S-P$_{2}$S$_{5}$ (LPS) with excellent electrochemical and morphological features is reported. The obtained solid electrolyte offers an ionic conductivity of 1.2 mS cm$^{-1}$ at room temperature and establishes a rather stable interphase with lithium. These enable rather high critical current densities (up to 1 mA cm$^{-2}$), as well as enhanced cathode active material utilization in solid-state lithium metal cells.