One-Pot Synthesis of SnO2/C Nanocapsules Composites as Anode Materials for Lithium-Ion Batteries

In this work, we demonstrate a facile route for the synthesis of nanostructured SnO2/C composites for lithium-ion batteries. The anode materials were prepared via a one-pot solvothermal approach and then calcination in a highly pure nitrogen atmosphere. The composited was composed of amorphous carbon and nanocrystalline SnO2 by the X-ray diffraction (XRD) analysis, and the content of carbon was calculated according to the thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) images revealed that the diameter of these as-prepared spheres varied from 50 to 60 nm. A systematic study has been carried out to examine the effect of carbon content upon lithium-ion battery performance. The electrochemical results showed that SnO2/C nanocomposite could achieve 1197.5 mAh/g reversible capacity and 55.11% initial coulombic efficiency, and 190% capacity retention after 50 cycles compared to the SnO2 nanoparticles of 940.6 mAh/g at a current density 0.2 C in the voltage range of 0.01 similar to 3.0 V. These improvements can be ascribed to the carbon, which can enhance the conductivity of SnO2, suppress the aggregation of active particles, and increase their structural stability during cycling.