Carbon-coated graphene-Cr2O3 composites with enhanced electrochemical performances for Li-ion batteries

Graphene-based Cr2O3 composites are prepared and exhibit better electrochemical properties than free Cr2O3 particles without the graphene. The synthesis procedure consists of the direct growth of CrOOH on the surface of graphene and the subsequent thermal decomposition of CrOOH to Cr2O3. Moreover, the electrochemical properties of graphene-based Cr2O3 are further improved through carbon coating, and two strategies are developed. Interestingly, the carbon layers pyrolyzed from glucose on CrOOH can separate the particles on the graphene and limit their growth, while those on Cr2O3 merely cover the particles and cannot prevent particle aggregation. Consequently, compared to the latter carbon-coated composite, the former shows further improved electrochemical behavior. (C) 2013 Elsevier Ltd. All rights reserved.