Bismuth-based compounds as efficient sulfur hosts for novel lithium-sulfur batteries

Abstract

Lithium-sulfur (Li–S) batteries have been paid more attention due to its high theoretical specific capacity (1675 mAh g⁻¹), but they still face many challenges in the commercialization process, especially the shuttle effect. Hence, reducing the shuttle of polysulfides is a key factor to obtain high-performance Li–S batteries. Inhere, bismuth based compounds were prepared as the sulfur host cathodes for Li–S batteries. Then the S@Co/N-CNTs@Bi₂S₃ and S@Co/N-CNTs@Bi₂O₃ composite cathodes were synthesized by alcohol heating and melt diffusion method. The as-prepared cathodes deliver a capacity decay rate of 0.038% and 0.056% during 900 cycles at 1 C, respectively. The outstanding cycling performance can be put down to the strong adsorption of Bi₂S₃ and Bi₂O₃ to polysulfides, inhibiting their dissolution and diffusion. The research proposed in this study will provide a new clue for bismuth based compounds as sulfur hosts to improve the cycle life of cathodes, and furnish a promising design strategy for the high-performance Li–S batteries.