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<middle dot>g(-1) at 5C), desirable reversibility (49.9% capacity retention after 300 cycles at 5C) and exceptional pouch cell performance (3.65 mAh<middle dot>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.