Synergistically accelerating capture and catalytic conversion of polysulfides by VS₂-MXene heterostructure as sulfur...

The shuttle effect of lithium polysulfides (LiPSs), coupled with the sluggish kinetics of redox reactions, imposes severe limitations on sulfur (S) utilization and undermines the cycling stability of lithium‑sulfur (LiS) batteries. Rational designing of three-dimensional (3D) porous S host materials with integrated adsorption-catalysis-conduction functionalities has emerged as a promising strategy to suppress LiPSs shuttle and accelerate redox kinetics. Herein, a 3D porous VS₂-MXene heterostructure is successfully synthesized via a hydrothermal method, where MXene served as the conductive substrate and is coupled with flower-like VS₂ nanostructures possessing abundant active sites. When used as a S host for the cathode, the synergistic effect between VS₂ and MXene not only provided plentiful anchoring sites for LiPSs and catalytic active centers but also established a 3D electron conduction network, thereby facilitating the catalytic conversion and redox kinetics of LiPSs. Given the aforementioned exceptional attributes, the LiS batteries incorporating the S/VS₂-MXene cathode demonstrate a reversible capacity of 938.64 mAh g^-1 after 200 cycles at 0.2C. Even at 2C, it delivers an excellent specific capacity of 753.43 mAh g^-1 with an ultralow capacity decay of only 0.027 % per cycle over 1000 cycles. More importantly, it demonstrates an outstanding areal capacity of 5.35 mAh cm^-2 under rigorous conditions of elevated S loading (5.4 mg cm^-2) and limited electrolyte (7.5 μL mg^-1). Furthermore, for a pouch-type battery, it maintains a specific capacity of 578.65 mAh g^-1 after 200 cycles at 1C. The results underscore the development of multifunctional heterostructure cathode provides a practical and effective strategy to enable high-performance LiS batteries.