Greatly Suppressed Shuttle Effect for Improved Lithium Sulfur Battery Performance through Short Chain Intermediates.

The high solubility of long-chain lithium polysulfides and their infamous shuttle effect in lithium sulfur battery lead to rapid capacity fading along with low Coulombic efficiency. To address above issues, we propose a new strategy to suppress the shuttle effect for greatly enhanced lithium sulfur battery performance mainly through the formation of short-chain intermediates during discharging, which allows significant improvements including high capacity retention of 1022 mAh/g with 87% retention for 450 cycles. Without LiNO3-containing electrolytes, the excellent Coulombic efficiency of ∼99.5% for more than 500 cycles is obtained, suggesting the greatly suppressed shuttle effect. In situ UV/vis analysis of electrolyte during cycling reveals that the short-chain Li2S2 and Li2S3 polysulfides are detected as main intermediates, which are theoretically verified by density functional theory (DFT) calculations. Our strategy may open up a new avenue for practical application of lithium sulfur battery.