High-Capacity\nC/Sn-Composites as Next-Generation Anodes\nfor Sodium-Ion Batteries

This work investigates\ncarbon/tin composites as anode materials\nfor high-performance sodium-ion batteries (SIBs). The material is\nprepared by dispersing SnO<sub>2</sub> nanopowder in fructose solution,\nfollowed by thermal treatment under inert gas, leading to fructose\ncarbonization and carbothermal reduction of SnO<sub>2</sub> forming\nmetallic Sn, confirmed by thermogravimetric analysis (TGA) and X-ray\ndiffraction (XRD). Different thermal procedures, including a single-step\nwith extended holding times and a two-step process, are explored;\nthe latter separates fructose carbonization from carbothermal reduction,\nwith the second step conducted under conventional heating conditions\nor via an ultrafast heating method. The composite with low carbon\ncontent exhibits a sodiation capacity of 749.2 mAh g<sup>–1</sup> in the first cycle with a high initial cycle efficiency (ICE) of\n83.2%. After 100 cycles at 37.2 mA g<sup>–1</sup>, it retains\na capacity of 351 mAh g<sup>–1</sup>. The material demonstrates\nexcellent rate capability, maintaining a capacity of 344.5 mAh g<sup>–1</sup> at a rate of 2380 mA g<sup>–1</sup>.