PREPARATION OF THREE-DIMENSIONAL GRAPHENE NETWORKS FOR USE AS ANODE OF LITHIUM ION BATTERIES

The three-dimensional (3D) graphene networks have been prepared by annealing the mixture of graphene oxide and SiO2 nanoparticles and then etching SiO2. The obtained material was characterized by X-ray diffraction, scanning electron microscope and transmission electron microscopy, which revealed that 3D networks consisting of crumpled graphene nanosheets were preserved after the removal of SiO2. When used as anode material of lithium ion batteries, the graphene networks showed a reversible capacity of 610.9 mAh/g at a current density of 50 mA/g after 50 cycles and excellent rate capability of 291.5 mAh/g at a current density of 5000 mA/g. The good electrochemical performance can be attributed to the network structure, which enables graphene to electrochemically absorb more lithium ions and significantly improve the electrical conductivity of electrode. The graphene networks have the potential applications in ultracapacitor and catalyst supports.