Suppression of Polysulfide Dissolution and Shuttling with Diphenyl Disulfide Electrolyte for Lithium Sulfur Batteries

Abstract

Lithium-sulfur (Li-S) systems have been rising stars in new battery technologies beyond lithium-ion battery rea, but the dissolution and shuttle of lithium polysulfide seriously deteriorate the cycling performance. Herein, we proposed diphenyl disulfide (DPDS) as the electrolyte additive for Li-S batteries. DPDS can interact with the discharge intermediate S2- 4/S2- 6 ions, changing the stable form of lithium polysulfide in the electrolyte, inhibiting the shuttle of lithium polysulfide, and protecting the lithium anode. The initial discharge specific capacity of a Li-S battery with conventional electrolyte at 0.5 C is 1352.6 mAh/g, and the specific capacity of a Li-S battery with 200 cycles is 790.5 mAh/g. The initial discharge specific capacity of the battery containing 5.0 wt.% DPDS electrolyte at 0.5 C was 1296.3 mAh/g, and the capacity after 200 cycles was 899.9 mAh/g.