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

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.