Lithium Sulfide: Magnesothermal Synthesis and Battery Applications

As a critical material for emerging lithium-sulfur batteries and sulfide-electrolyte-based all-solid-state batteries, lithium sulfide (Li2S) has great application prospects in the field of energy storage and conversion. However, commercial Li2S is expensive and is produced via a carbon-emissive and timeconsuming method of reducing lithium sulfate with carbon materials at high temperatures. Herein we report a novel method of synthesizing Li2S by thermally reducing lithium sulfate with the first non-carbon-based reductant Mg. Compared with the commercial carbothermal method, our magnesothermal technique has multiple advantages, such as completion in minutes, operation at lower temperatures, emission of zero amount of greenhouse gases, and a valuable byproduct MgO. Moreover, the prepared Li2S product demonstrates excellent cathode performance in lithium-sulfur batteries, in terms of cycling stability, activation voltage, and rate capability. Thus, this innovative method opens a new direction for the research of Li2S and has great potential for practical applications.

Automated summary

This study presents a novel method for synthesizing Li2S by thermally reducing lithium sulfate with non-carbon-based reductant Mg. Compared with the traditional carbothermal method, this magnesothermal technique offers multiple advantages such as shorter reaction time, lower operation temperature, zero greenhouse gas emissions, and the formation of a valuable byproduct MgO. Furthermore, the prepared Li2S product exhibits excellent performance in lithium-sulfur batteries.