Modifying Separators with a Multistrategy-Constructed (ZnCo)3S4–MoS2 Heterostructure for High-Performance Lithium–Sulfur Batteries

Abstract

Lithium–sulfur (Li–S) batteries are considered promising candidates for next-generation energy storage systems. Developing high-efficiency catalysts to improve kinetics and inhibit the shuttle effect is a challenging task. In this study, a three-dimensional (3D) (ZnCo)₃S₄–MoS₂ heterostructure was constructed at the nanoscale and used as a decoration for the separator of durable Li–S batteries. Benefiting from the generation of the built-in electric field between 3D (ZnCo)₃S₄ and in situ grown MoS₂ nanosheet, the rapid transport of ions and electrons and excellent polysulfide redox kinetics are observed in the (ZnCo)₃S₄–MoS₂, which results in a smooth ″adsorption–diffusion–conversion″ process of polysulfides. The Zn dopant effectively reduces the work function of Co₃S₄ via an electron transfer from Zn to Co₃S₄, strengthening the built-in electric field. The battery equipped with the (ZnCo)₃S₄–MoS₂ nanomaterial-modified separator delivers a high initial discharge capacity of 1180.5 mAh g^–1 at 1 C conditions and a low attenuation rate of 0.054% after 1000 cycles. In addition, the battery also exhibits good cycling stability at a high sulfur loading of 3 mg·cm^–2, maintaining a capacity of 704.4 mAh g^–1 (84.9% capacity retention) after 200 cycles at 0.1 C. This study provides a promising strategy to design highly efficient catalysts for durable Li–S batteries.