SnO2-NiO-C nanocomposite as a high capacity anode material for lithium-ion batteries

Carbon-coated SnO2-NiO nanocomposite was successfully synthesized via the molten salt route, using SnCl2 center dot H2O and NiCl2 center dot 6H(2)O as the starting materials, with a molten salt composition of H2O2 : LiOH center dot H2O : LiNO3 as a solvent at 300 degrees C. The synthesis was followed by a carbon layering process. The phases and morphology of the as-prepared samples were examined by X-ray diffraction and transmission electron microscopy. Electrochemical investigation was carried out by using a series of complementary techniques, including galvanostatic charge-discharge, cyclic voltammetry, and impedance spectroscopy. The results confirmed that the carbon-coated SnO2-NiO nanocomposite has higher discharge capacity, better rate capability, and excellent cycling performance in comparison to the uncoated SnO2-NiO nanocomposite. The carbon-coated SnO2-NiO nanocomposite electrode exhibited a reversible capacity of about 529 mA h g(-1) at 800 mA g(-1), and 265 mA h g(-1) at 1600 mA g(-1), even after 500 cycles. The excellent electrochemical performance of the SnO2-NiO-C nanocomposite can be mainly attributed to the combined effects of the nanostructure, the carbon layering on the SnO2 and NiO nanoparticles, and the ultra-fine carbon matrix, because the three factors would contribute to high electronic conductivity, reduce the traverse time of electrons and lithium ions, and also prevent high volume expansion during cycling. Due to its excellent electrochemical performance, the SnO2-NiO-C nanocomposite could be considered as a promising anode material for future lithium-ion batteries to be used in electric vehicles and hybrid electric vehicles.