Electrospun CoSe@NC nanofiber membrane as an effective polysulfides adsorption-catalysis interlayer for Li-S batteries

Lithium sulfur (Li-S) batteries have attracted tremendous attention due to their low cost and high theoretical capacity. However, the serious polysulfides shuttle and slow redox reaction kinetics hinder their large-scale commercial applications. Various attempts have been made to solve the problems. Herein, a [email protected] nanofiber membrane was prepared by electrospinning method and used as independent functional interlayer for the Li-S batteries. The visualized adsorption experiments show that the [email protected] nanofiber 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 [email protected] can therefore effectively enhance the rate performance and cycling stability of Li-S batteries. The cell assembled with [email protected] functional interlayer delivers a high initial reversible discharge capacity of 1317 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