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

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.