Catalytic VS2–VO2 Heterostructure that Enables a Self‐Supporting Li2S Cathode for Superior Lithium–Sulfur Batteries

Abstract

AbstractLithium–sulfur batteries (LSBs) have become very promising next‐generation energy‐storage technologies owing to their high energy densities and cost‐effectiveness. However, the poor electrical conductivity of the active material, volume changes that occur during cycling, the “shuttle effect” involving lithium polysulfides (LiPSs), and lithium dendrite growth limit their commercializability. Herein, the preparation of a CC@VS2–VO2@Li2S@C electrode prepared by the in situ growth of a VS2–VO2 heterostructure on carbon cloth (CC), loaded with Li2S, and finally coated with a carbon shell, is reported. The cell with the CC@VS2–VO2@Li2S@C cathode exhibits superior cycling stability and rate performance owing to synergy between its various components. The cell delivers a high discharge specific capacity of 919.8 mA g−1 at 0.2 C, with a capacity of 588.9 mAh g−1 retained after 500 cycles with an average capacity attenuation of 0.072% per cycle. The cell exhibits discharge capacities of 937.6, 780.2, 641.9, 541, and 462.8 mAh g−1 at current densities of 0.2, 0.5, 1, 2, and 3 C, respectively. This study provides a new approach for catalyzing LiPS conversion and promoting LSB applications.