One-Pot Decoration of Graphene with SnO₂ Nanocrystals by an Elevated Hydrothermal Process and Their Application as Anode Materials for Lithium Ion Batteries

Tin dioxide (SnO₂), with a high theoretical storage capacity of 782 mAhg⁻¹, is a potential alternative anode for rechargeable lithium ion batteries (LIBs). However, its low electronic conductivity and poor stability during cycling (due to a change in volume) hinder its practical applications for energy storage. Composite materials of SnO₂-nanocrystal-decorated graphene, which show excellent electrochemical characteristics, were prepared using a one-pot elevated hydrothermal method at 250 °C without subsequent carbonization treatment. The effects of graphene, solvent composition, and temperature on the morphology, structure, and electrochemical properties of the SnO₂/graphene composites were investigated using XRD, SEM, TEM, and N₂ adsorption–desorption techniques. The as-prepared SnO₂/graphene composites deliver a high initial discharge capacity of 1734.1 mAh g⁻¹ at 200 mA g⁻¹ and exhibit a high reversible capacity of 814.7 mAh g⁻¹ even after 70 cycles at a current density of 200 mA g⁻¹. The composites also exhibit a high rate capability of 596 mAh g⁻¹ at 2000 mAg⁻¹, indicating a long cycle life and promising capability when used as anode materials for lithium ion batteries and suggesting that SnO₂/graphene composites have wide application prospects in LIBs.