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.