High-Capacity C/Sn-Composites as Next-Generation Anodes for Sodium-Ion Batteries

Abstract

This work investigates carbon/tin composites as anode materials for high-performance sodium-ion batteries (SIBs). The material is prepared by dispersing SnO₂ nanopowder in fructose solution, followed by thermal treatment under inert gas, leading to fructose carbonization and carbothermal reduction of SnO₂ forming metallic Sn, confirmed by thermogravimetric analysis (TGA) and X-ray diffraction (XRD). Different thermal procedures, including a single-step with extended holding times and a two-step process, are explored; the latter separates fructose carbonization from carbothermal reduction, with the second step conducted under conventional heating conditions or via an ultrafast heating method. The composite with low carbon content exhibits a sodiation capacity of 749.2 mAh g^–1 in the first cycle with a high initial cycle efficiency (ICE) of 83.2%. After 100 cycles at 37.2 mA g^–1, it retains a capacity of 351 mAh g^–1. The material demonstrates excellent rate capability, maintaining a capacity of 344.5 mAh g^–1 at a rate of 2380 mA g^–1.