Flower-like CuO and flower-like CuO/graphene composite were prepared successfully by hydrothermal method. They were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, temperature-pr...Flower-like CuO and flower-like CuO/graphene composite were prepared successfully by hydrothermal method. They were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, temperature-programmed reduction, and thermogravimetric analysis. It is found that the flower-like CuO microspheres, which are composed of CuO nanosheets, possess an average diameter of 4.2 μm and a Brunauer–Emmett–Teller surface area of 12.6 m2/g. Compared with the flower-like CuO, the obtained flower-like CuO/graphene composite shows an enhanced electrochemical performance with a higher capacity of 603 mA-h/g at 0.1 C rate and 382 mA-h/g at 1 C rate, and exhibits a better cycle stability with a high capacity retention of 95.5 % after 50 cycles even though at 1 C rate.展开更多
The use of new three-dimensional （3D） porous graphene-metal oxide composite microspheres as an anode material for Li-ion batteries （LIBs） is first introduced here. 3D graphene microspheres are aggregates of indivi...The use of new three-dimensional （3D） porous graphene-metal oxide composite microspheres as an anode material for Li-ion batteries （LIBs） is first introduced here. 3D graphene microspheres are aggregates of individual hollow graphene nanospheres composed of graphene sheets. Metal oxide nanocrystals are uniformly distributed over the graphene surface of the microspheres. The 3D porous graphene-SnO2 microspheres are selected as the first target material for investigation because of their superior electrochemical properties. The 3D porous graphene-SnO2 and graphene microspheres and bare SnO2 powders deliver discharge capacities of 1,009, 196, and 52 mAh·g^-1, respectively, after 500 cycles at a current density of 2 A·g^-1 .The 3D porous graphene-SnO2 microspheres exhibit uniquely low charge transfer resistances and high Li-ion diffusivities before and after cycling.展开更多
基金Project (20110490594) supported by China Postdoctoral Science Foundation
文摘Flower-like CuO and flower-like CuO/graphene composite were prepared successfully by hydrothermal method. They were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, temperature-programmed reduction, and thermogravimetric analysis. It is found that the flower-like CuO microspheres, which are composed of CuO nanosheets, possess an average diameter of 4.2 μm and a Brunauer–Emmett–Teller surface area of 12.6 m2/g. Compared with the flower-like CuO, the obtained flower-like CuO/graphene composite shows an enhanced electrochemical performance with a higher capacity of 603 mA-h/g at 0.1 C rate and 382 mA-h/g at 1 C rate, and exhibits a better cycle stability with a high capacity retention of 95.5 % after 50 cycles even though at 1 C rate.
文摘The use of new three-dimensional （3D） porous graphene-metal oxide composite microspheres as an anode material for Li-ion batteries （LIBs） is first introduced here. 3D graphene microspheres are aggregates of individual hollow graphene nanospheres composed of graphene sheets. Metal oxide nanocrystals are uniformly distributed over the graphene surface of the microspheres. The 3D porous graphene-SnO2 microspheres are selected as the first target material for investigation because of their superior electrochemical properties. The 3D porous graphene-SnO2 and graphene microspheres and bare SnO2 powders deliver discharge capacities of 1,009, 196, and 52 mAh·g^-1, respectively, after 500 cycles at a current density of 2 A·g^-1 .The 3D porous graphene-SnO2 microspheres exhibit uniquely low charge transfer resistances and high Li-ion diffusivities before and after cycling.
