Synthesis of bismuth sulfide/reduced graphene oxide composites and their electrochemical properties for lithium ion batteries

A simple one-pot hydrothermal route was developed to synthesize bismuth sulfide/reduced graphene oxide composites (Bi2S3/RGO composites) in this work. The morphology and crystalline structure of the obtained products were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high resolution transmission electron microscopy (HRTEM). The results of Raman spectra and Fourier transform infrared (FTIR) spectra demonstrated that graphite oxide (GO) sheets were in situ reduced to a certain extent. Transmission electron microscopy (TEM) observation indicated that the Bi2S3 nanoparticles, with a size of 80-100 nm in length, are anchored on RGO sheets. Electrochemical tests show the Bi2S3/RGO composite exhibits an extraordinary capacity of 1073.1 mAh g(-1) with excellent cycling stability and high rate capability compared to pure Bi2S3 particles prepared by a similar route in the absence of GO. The enhancement in the electrochemical performance could be attributed to the introduction of RGO sheets that not only buffer the large volume changes during the alloy/dealloy reaction of Li and Bi, but also provide a highly conductive network for rapid electron transport in electrode during electrochemical reaction. (C) 2013 Elsevier Ltd. All rights reserved.