Paving the Way for Using Li₂S Batteries

In this work, a novel lithium–sulfur battery was developed comprising Li₂S as the cathode, lithium metal as the anode and polysulfide-based solution as the electrolyte. The electrochemical performances of these Li₂S-based cells strongly depended upon the nature of the electrolytes. In the presence of the conventional electrolyte that consisted of lithium bis(trifluoromethanesulfonyl)-imide (LiTFSI) salt dissolved in a solvent combination of dimethoxyethane (DME)/1,3-dioxolane (DOL), the Li/Li₂S cells showed sluggish kinetics, which translated into poor cycling and capacity retention. However, when using small amounts of polysulfides in the electrolyte along with a shuttle inhibitor the Li₂S cathode was efficiently activated in the cell with the generation of over 1000 mAh g⁻¹capacity and good cycle life.