Enhanced Structural VS4 Grown onto Hollow Carbon Mesoporous Spheres via Surficial Bonding for High Cycling Stability in Sodium‐Ion Batteries

Transition metal sulfides are recognized as an excellent alternative to sodium ion anodes ascribed to the outstanding theoretical capacity. The unique crystal arrangement of VS₄ gives it exceptional theoretical capacity, despite challenges like insufficient electrical conductivity and undesirable volume expansion. Herein, a novel stabilized anode featuring a distinctive 3D hollow spherical structure is proposed, providing a simple strategy to synthesize such anodes for VS₄-HCMSs bonded via C-O-S and V-O-C interfaces. The kinetic investigations and density functional theory reveal that the unique structure connected by interfacial bonds enhances Na⁺ transport rate and charge transfer efficiency, while carbon greatly mitigates the volume expansion. Unsurprisingly, the VS₄-HCMSs exhibit an impressive first-cycle Coulombic efficiency of 91.31% and an ultrahigh reversible capacity of 612 mAh g^-1 after 300 cycles at 0.5 A g^-1, even exhibit the reversible capacity of 498.8 mAh g^-1 after 1000 cycles at 5 A g^-1. Additionally, the NaFePO₄//VS₄-HCMSs full cell is cycled for 200 cycles at 0.2 C and powered the light-emitting diodes for up to 30 minutes afterward. Overall, this work enhances the conductivity and stability of the material by combining VS₄ with hollow carbon mesoporous spheres through interfacial bonding, offering an efficient strategy to anode materials in sodium-ion batteries.