Si/li2s battery with solvate ionic liquid electrolyte

Abstract

A lithium-sulfur cell was developed, consisting of a Si nanoflake negative electrode, a Li2S/graphene positiv electrode, and a non-flammable solvate ionic liquid electrolyte. This cell configuration allows us to avoid the use o Li metal electrode and the concomitant dendritic deposition of Li metal at the negative electrode during charging thereby rendering the cell operation highly safe and stable. The solvate ionic liquid electrolyte solution wa composed of tetraglyme, lithium bis(trifluoromethanesulfonyl)amide, and a hydrofluoroether. The solubility o lithium polysulfide (reaction intermediate of the positive electrode) is very low, resulting in high Coulombi efficiency of discharge/charge and long cycle life of the Si/Li2S cell.