Synergistic Structural and Defect Engineering in MoS₂ Featuring Ultra-Expanded Interlayers for Fast-Chargeable and...

Molybdenum disulfide (MoS₂) is a promising anode for sodium-ion batteries (SIBs) owing to its high theoretical specific capacity, yet it suffers from sluggish kinetics, severe volume variation, and unstable solid electrolyte interphase (SEI). Theoretically, concurrent selenium doping and carbon intercalation are revealed to effectively mitigate these challenges by improving electronic conductivity, promoting phase transition reaction kinetics, and alleviating structural deformation, thereby improving the structural flexibility of the MoS₂ anode. Experimentally, a synergistic hollow carbon sphere-confined, carbon-intercalated and selenium-doped MoS₂ (MoSSe@HCS) anode is rationally designed, achieving an ultra-expanded interlayer spacing (1.24 nm), appropriate buffer space and robust carbon encapsulation. This design boosts charge-transfer kinetics, suppresses volume variation, and stabilizes SEI. Consequently, the MoSSe@HCS anode exhibits high capacity (441.5 mAh g^-1, 100 cycles at 0.1 A g^-1), exceptional rate capability (121.9 mAh g^-1 at 30 A g^-1), and cyclability (87.3% capacity retention after 1000 cycles at 10 A g^-1). A full cell with Na₃V₂(PO₄)₃ cathode displays high-capacity retention of 82.1% after 600 cycles at 17 C and a pouch-type full cell sustains over 2500 cycles at 10 C, demonstrating significant commercial viability. This work establishes a theory-guided design paradigm that bridges fundamental understanding and practical deployment of high-performance MoS₂-based anodes for next-generation SIBs.