Engineering Triple‐Nanolayer VN/C@TCF Cathode with Synergistic Polysulfide Regulation for High‐Performance Li‐S Batteries

Abstract Lithium‐sulfur batteries face three fundamental challenges: uncontrolled polysulfide shuttling, substantial volumetric fluctuations during cycling, and the inherent electrical insulation of sulfur. To address these limitations, an asymmetric self‐supporting cathode is developed, featuring TiO₂‐decorated carbon nanofibers synergistically integrated with hollow carbon shells encapsulating vanadium nitride catalysts (VN/C@TCF). Distinct from conventional configurations, this hierarchically structured “triple‐nanolayer” system establishes sequential mitigation mechanisms: (I) TiO 2 nanoparticles in the inner layer provide chemical immobilization of polysulfides; (II) the intermediate hollow carbon shell enables physical confinement; (III) the outer VN nanosheets offer chemical anchoring capacity. Combined density functional theory calculations and experimental analyses reveal that the VN/C@TCF architecture simultaneously enhances electrical conductivity, demonstrates superior catalytic activity, and accommodates volume variations during electrochemical cycling. The optimized cathode delivers exceptional performance metrics, including a high initial discharge capacity of 1417.9 mAh g⁻¹ at 0.1 C and remarkable rate capability (803.2 mAh g⁻¹ at 5 C). Notably, the electrode can maintain an impressive areal capacity of 6.30 mAh cm⁻ 2 after 80 cycles under stringent operational conditions with high sulfur loading (8.1 mg cm⁻ 2 ) and lean electrolyte (E/S ratio = 4.8 µL mg⁻¹). This strategic design paradigm provides new insights for developing integrated electrocatalytic systems in advanced lithium‐sulfur batteries.