An electrolyte solution for a lithium sulfur battery contains a lithium oxalatoborate compound in a 0.05-2 M solution in conventional lithium sulfur battery electrolyte solvents, optionally with other lithium compounds. Examples of solvents include dimethoxyethane (DME), dioxolane, and triethyleneglycol dimethyl ether (TEGDME). Electrochemical cells contain a lithium anode, a sulfur-containing cathode, and a non-aqueous electrolyte containing the lithium oxalatoborate compound. Lithium sulfur batteries contain a casing enclosing a plurality of the cells.