Effective polysulfides regulation in high-performance Li–S batteries via novel VO2–VS2 heterostructure

Developing effective heterostructure strategies to mitigate the shuttling effect and accelerate lithium polysulfide (LiPS) conversion remains a critical challenge in lithium–sulfur (Li–S) batteries. Here, we report the first carbon–free VO₂–VS₂ heterostructure material synthesized via in situ sulfurization, applied as a modifier on a commercial polypropylene (PP) separator (denoted as VO₂–VS₂@PP). The as–prepared VO₂–VS₂ nanorods synergistically combine the high absorptivity of VO₂ with the efficient catalytic properties of VS₂, simultaneously enhancing LiPS anchoring and promoting its conversion. We systematically investigate the influence of material composition on battery performance, leveraging these functional attributes, Li–S cells incorporating VO₂–VS₂@PP exhibit exceptional cycle stability (over 500 cycles at 1C), impressive rate performance (807 mAh·g^–1 at 5C), desirable reversibility (49.9% capacity retention after 300 cycles at 5C) and exceptional pouch cell performance (3.65 mAh·cm^–2 after 50 stable cycles at 0.1C). This study underscores the potential of tailored heterostructures in realizing high–performance Li–S batteries, offering new insights for next–generation energy storage solutions.

Graphical abstract