LAUSR

Abstract Lithium sulfur batteries (Li-S) have attracted tremendous attention due to their low cost and high theoretical capacity. However, the serious polysulfides shuttle and slow redox reaction kinetics hinder the large-scale commercial applications. Various attempts have been made to solve these problems. Herein, a CoSe@NC nanofiber membrane was prepared by electrospinning method and used as independent functional interlayer for the Li-S batteries. The visualized adsorption tests show that the CoSe@NC nanofiber membrane exhibits strong adsorption capability for polysulfides; In addition, CoSe nanoparticles with strong catalytic activity can accelerate the conversion of polysulfides. The adsorption-catalysis synergy of CoSe@NC can therefore effectively enhance the rate performance and cycling stability of Li-S batteries. The cell assembled with CoSe@NC functional interlayer delivers a high initial discharge capacity of 1217 mAh g-1 at 0.1 C rate. After 200 cycles at 1.0 C, the capacity decay rate is only 0.16% per cycle. This work provides a feasible way to promote the electrochemical performance of Li-S batteries.