Enhanced Polysulfides Adsorption and Conversion on FeS 2 @CNF Modified Separator for Li-S Batteries

Abstract

Lithium-sulfur (Li-S) batteries have garnered extensive attention due to their remarkable theoretical capacity and costeffectiveness. Nevertheless, their practical commercialization has been hindered by the pronounced shuttle effect and sluggish redox reaction kinetics. Herein, a carbon nanofiber (FeS2@CNF) functionalized with FeS2 nanoparticles was developed as a high-performance separator for Li-S batteries, enabling efficient polysulfide adsorption, enhanced redox kinetics, and effective mitigation of the shuttle effect. Consequently, the Li-S cell integrating FeS2@CNF demonstrates an outstanding initial specific capacity of 1455.3 mAh g⁻¹ at 0.5C, retaining 830.7 mAh g⁻¹ after 400 cycles with an ultralow capacity decay rate of just 0.16%. This work offers a promising strategy for the rational design of advanced separators in Li-S batteries.