Exceptional electrochemical performance of rechargeable Li–S batteries with a polysulfide-containing electrolyte

Soluble lithium polysulfides (Li2Sx, x ≥ 6) were used as co-salts/additives in an ether-based electrolyte for lithium sulfur (Li–S) batteries. By optimizing the concentration of the polysulfide species and the amount of electrolyte, the Li–S batteries show high and stable discharge capacity, outstanding rate capability, and exceptional cycling performance.