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 time-consuming
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.