Solvothermal synthesis of V2O5/graphene nanocomposites for high performance lithium ion batteries

In this work, V2O5/graphene nanocomposites have been synthesized by a facile solvothermal approach. The V2O5 nanoparticles, around 20-40 nm in size, were encapsulated in the 2D graphene matrix. The reversible Li-cycling properties of V2O5/graphene have been evaluated by galvanostatic discharge-charge cycling, cyclic voltammetry, and impedance spectroscopy. Compared with the bare V2O5 nanopartides, the V2O5/graphene nanocomposites exhibited enhanced electrochemical performance with higher reversible capacity and improved cycling stability and rate capability. The graphene nanosheets act not only as an electronically conductive matrix to improve the electronic and ionic conductivity of the composite electrode, but also as a flexible buffer matrix to maintain the structural integrity of the composite electrodes by preventing particle agglomeration, thus leading to the improvement of the electrochemical performance of V2O5. (C) 2014 Elsevier B.V. All rights reserved.