Lithium-Sulfur Battery Electrolyte Protocol

The blank electrolyte was 1 M lithium bis(trifluoromethanesulfonyl) imide (LiTFSI, 99.95% trace metal basis from Sigma-Aldrich, Saint Louis, MO, USA) dissolved in 1,3-dioxolane (DOL, 99.8% from Sigma-Aldrich) and 1,2-dimethoxyethane (DME, 99.5% from Sigma-Aldrich) (1:1 volume ratio). Lithium nitrate (LiNO₃, 99.99% from Aldrich, 1 wt. %) was added to develop a stable solid-electrolyte-interphase (SEI) on the surface of the Li metal anode during cycling. The catholyte (1 M Li₂S₆) was prepared by dissolving stoichiometric amount of Li₂S (99.9% from Alfa-Aesar, Haverhill, MA, USA) and sulfur (≥99.5% from Sigma-Aldrich) in the blank electrolyte.