Preparation of Sn-Co-graphene composites with superior lithium storage capability

Sn-Co-graphene composites have been synthesized through a facile one pot co-precipitation method. The as-prepared composites are investigated by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and elemental analysis. The results indicate that Sn-Co nanoparticles are homogeneously attached to the surface of graphene. The lithium storage capability of the composites is evaluated by cyclic voltammetry and galvanostatic charge-discharge tests. Results show that the composites exhibit high reversible capacity with excellent cyclic stability and rate capability. The superior lithium storage capability could be ascribed to the positive synergistic effect of the combination of the buffering effects of cobalt and the excellent conductivity of graphene, which could restrain the volume variation, keep the structure stable, and increase the conductivity of the whole system. (C) 2014 Elsevier Ltd. All rights reserved.