Interface and Structure Engineering of Tin‐Based Chalcogenide Anodes for Durable and Fast‐Charging Sodium Ion Batteries

Abstract Transition metal dichalcogenides with high theoretical capacity usually suffer from poor intrinsic electronic conductivity and drastic volumetric change upon cycling, degrading their attractiveness for electrochemical high‐power and long‐term applications. Herein, a high‐efficiency and extensible synthetic strategy for in situ encapsulating nanostructured SnSe 0.5 S 0.5 into N‐doped graphene (SnSe 0.5 S 0.5 @ NG) by robust interfacial CSeSn bonds with formation of 3D porous network nanohybrids, is reported. Systematic electrochemical studies indicate that interface and structure engineering on SnSe 0.5 S 0.5 , including defects implantation, chemical bonding interaction, and nanospace confinement design, endow it with robust structural stability, ultrafast Na + storage kinetics, and highly reversible redox reaction. In addition, the introduction of foreign Se ligand not only facilitates the transport of electrons/ions by enhancing the conductivity and decreasing the diffusion energy barrier but also generates more reactivity sites, as demonstrated by density functional theory calculations. By virtue of these superiorities, the SnSe 0.5 S 0.5 @ NG exhibits superior sodium storage performance with high‐rate capability and long durability over 2000 cycles at 2 A g −1 . Impressively, the full battery, when coupling SnSe 0.5 S 0.5 @ NG anode with Na 3 V 2 (PO 4 ) 3 /C cathode, can deliver high energy density of 213 Wh kg −1 . This work provides an effective structural engineering strategy to design advanced electrode material with potential application for sodium‐ion batteries.