Carbon-coated SnO2 nanoparticles were prepared by a novel facile route using commercial SnO2 nanoparticles treated with concentrated sulfuric acid in the presence of sucrose at room temperature and ambient pressure. The key features of this method are the simple procedure, low energy consumption, and inexpensive and non-toxic source materials. As-prepared core/shell nanoparticles were characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The electrochemical measurements showed that the carbon-coated SnO2 nanoparticles with 10% carbon and using carboxymethyl cellulose (CMC) as a binder displayed the best electrochemical performance with the highest specific capacity of 502mAhg−1 after 50 cycles at a current density of 100mAg−1. In addition, owing to the water solvability of CMC, the usage of CMC as binder makes the whole electrode fabrication process cheaper and more environmental friendly.