Effects of calcination on the preparation of carbon-coated SnO2/graphene as anode material for lithium-ion batteries

Carbon-coated SnO2/graphene (SnO2-C/GN) composites with high electrochemical performance are prepared via hydrothermal method followed by a facile calcination at different temperatures. The effects of calcination temperature on the structure and morphology as well as electrochemical behavior of synthesized SnO2-C/GNs are systematically investigated by X-ray diffraction, Fourier transform infrared spectrometry, transmission electron microscopy, and related electrochemical performance tests. The results show that the as-made SnO2-C/GNs calcined at 500 degrees C has the smallest charge transfer resistance, the largest lithium ion diffusion coefficient and the best cycling stability, exhibiting a stable capacity of 460 mAh g(-1) even after 120 cycles at a current density of 200 mA g(-1). The simple calcination process with proper temperature can effectively promote the uniformity of dispersed SnO2 nanoparticles and the formation of an excellent conjugated system with high electrical conductivity by graphene and homogeneous carbon, which contribute to the improved electrochemical properties of as-made SnO2-C/GNs. (C) 2014 Elsevier B.V. All rights reserved.