V2O5 plates anchored in CNTS composite materials with a network structure as polysulfide capture for lithium–sulfur battery

Abstract

Lithium-sulfur batteries (Li–S) are one of the future battery systems due to environmental friendliness and high theoretical specific capacity. However, the commercial development of Li–S battery faces numerous challenges, including the back-and-forth shuttle of long-chain polysulfides and the insulating properties of sulfur. To address these difficulties, we here prepared a carbon nanotubes/V2O5 plates/S (CNTs/V2O5/S) material as the host material. The CNTs can serve as a conductive network that speeds up the sulfur reaction rate. In addition, the polar V2O5 plates can effectively hinder the dissolution of polysulfides. The specific capacity of the CNTs/V2O5/S electrode was 709.9 mAh/g−1 at 0.1C, and the capacity retention rate was 72.6% over 100 cycles. After 500 cycles, the capacity retention efficiency is 71.7% and the decay rate is 0.056% at 1C. As-prepared CNTs/V2O5 composites, on the one hand, CNTs can enhance electron transport. On the other hand, the polar V2O5 plates block polysulfide diffusion. This provides a novel route for manufacturing Li–S batteries.