Unique polysulfide reaction on VO2 for restraining shuttle effect in soft-packaged Li–S pouch cells

The shuttle phenomenon and retarded conversion kinetics of lithium polysulfides(LiPSs)are relatively severe in lithium-sulfur(Li-S)pouch cells.Owing to their redox potential in the sulfur working window,VO2 nanobelts show unique working mechanism,mainly pertaining to the reversible conversion of"Li2Sn(n ≥ 4)⇄ thiosul-fate ⇄ polythionate complexes",giving rise to its ultrafast LiPSs anchoring behaviour.We herein make full use of the well-defined action mechanism of VO2 to enable the electrochemical performance of soft-packaged Li-S pouch batteries toward commercial realization.With tuning the VO2 content,the initial discharge capacity of the pouch cell at 0.2C cycle is up to 1075.1 mAh.g-1,and a remarkable capacity retention of 593.6 mAh·g-1 after 200 cycles at 1C is also achieved.This work provides deep insights and solutions for the critical issues resolving of present electrolyte-flooded soft-packaged Li-S pouch cells.