1T‐WS₂ Nanosheet‐Modified Biomass Carbon as Sulfur Host for High‐Performance Lithium–Sulfur Batteries

Abstract

The sluggish sulfur reaction kinetics and fast capacity attenuation still pose great challenges to lithium‐sulfur (Li–S) batteries. In this work, tubular carbonl (HPOC) was obtained by carbonization of the Cattail fiber. 1T‐WS2@HPOC was prepared by solvothermal method, and their sulfur composite, 1T‐WS2@HPOC/S and HPOC/S as sulfur host composite, are obtained by sulfur melting. The composite materials were characterized by scanning electron microscopy, X‐ray diffraction, thermogravimetry, and X‐ray photoelectron spectroscopy etc. Results showed that 1T‐WS2 grew uniformly on the HPOC substrate and had abundant active sites, which could effectively improve the physicochemical adsorption capacity of S‐fixation (76 wt%) and polysulfide. Battery assembly and electrochemical performance tests were conducted for the HPOC/S and 1T‐WS2@HPOC/S composites. Results showed that the initial discharge capacity of the 1T‐WS2@HPOC/S positive electrode is 1272 mAh/g at 0.1 C, higher than the HPOC/S positive electrode (1025 mAh/g). 1T‐WS2@HPOC/S maintains a discharge capacity of 695 mAh/g after 500 cycles at 0.5 C, with a capacity decay rate of only 0.054% per cycle. With a discharge capacity of 504 mAh/g after 400 cycles at 1C, the Coulomb efficiency is 98.9%. The 1T‐WS2@HPOC/S composites with unique structure and excellent electrochemical performance have broad application prospects in the field of Li–S batteries.This article is protected by copyright. All rights reserved.