Synthesis and Electrochemical Properties of Mesoporous SnO2/C Composites as Anode Materials for Lithium Ion Batteries

Mesoporous SnO2/C composites are prepared by a facile microemulsion method at ambient temperature followed by calcination under N2 at 600 o C for 2 h. The microstructure and morphology of the samples were characterized by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscope. Galvanostatic discharge/charge tests, cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize their electrochemical properties. It is demonstrated that the SnO2/C composites exhibit good electrochemical performance. After 50 discharge/charge cycles, they are able to deliver a capacity of 571 mAh·g-1 at a current density of 100 mA·g-1, which is two times greater than that of bare SnO2 nanoparticles. Such enhanced Li-ion intercalation performance can be attributed to the composites consisting of nanoparticles with fine crystalline size of around 5 nm compared with bare SnO2 nanoparticles with about 15 nm, the carbon nano-coating increasing electronic conductivity and the mesoporous structure of the composites