Uniformly Controlled Treble Boundary Using Enriched Adsorption Sites and Accelerated Catalyst Cathode for Robust Lithium-Sulfur Batteries

Rechargeable lithium-sulfur batteries (LSBs) are recognized as a promising candidate for next-generation energy storage devices because of their high theoretical specific capacity and energy density. However, the insulating of sulfur, Li2S2/Li2S, and the shuttling effect of high order lithium polysulfides (LiPSs) hinder its practical applications. Herein, a heterostructure is explored to enhance the conversion reaction kinetics and adsorption ability of LiPSs. By rationally designing a conductive carbon framework and polar metal sites, both experimental and theoretical results show strong adsorption abilities for dissolved LiPSs and promote the conversion reaction rate. A CoSe2/Co3O4@NC-CNT/S cathode shows an excellent rate performance (approximate to 1457 mAh g(-1) at 0.1 C and still retains approximate to 688 mAh g(-1) at a high rate of 5 C). When performing charge-discharge in long-term stability at 2 C, the CoSe2/Co3O4@NC-CNT/S cathode delivers a high initial specific capacity of approximate to 780 mAh g(-1) and retains approximate to 602 mAh g(-1) after 500 cycles with an excellent Coulombic efficiency of approximate to 95.4%. Remarkably, the battery can entirely operate even at a very high sulfur loading of approximate to 10.1 mg cm(-2) and lean electrolyte condition. This work emphasizes a new strategy to rationally design heterostructures that can encourage the industrial application of LSBs.

Automated summary

This study enhances the adsorption ability and reaction rate of high order lithium polysulfides in lithium-sulfur batteries by designing a heterostructure, leading to excellent rate performance and long-term stability.