Although many SnO2/graphenecomposite anode materials have been reported recently, theactive component, SnO2, is mostly a simple nanoparticle inthese composites,30,31,35,38,39,42,43,52,53 which is suggested to beless desirable for LIB application. Synthesis of two-dimensional(2D) nanosheets of non-layered metal oxides such as TiO2 andSnO2 is intrinsically challenging. Recently anatase TiO2nanosheets have been shown to exhibit superior lithiumstorage properties.54–56 However, synthesis and lithium storageproperties of unique SnO2 nanosheets are less investigated.57–64Herein, we demonstrate a new hydrothermal method todirectly grow SnO2 nanosheets on a graphene oxide supportthat is subsequently reduced to graphene. By forming thegraphene-supported SnO2 nanosheets (G-SnO2 NSs), onemight be able to take advantage of both components. Asexpected, in comparison to bare SnO2 NSs without a graphenesupport, the as-prepared G-SnO2 NSs exhibit greatlyenhanced lithium storage properties with high reversible capacityand good cyclic capacity retention after prolonged cycling.Fig. 1 shows the morphology of the as-prepared G-SnO2NSs. It is obvious that large two-dimensional (2D) structurescan be observed under scanning electron microscopy (SEM;Fig. 1A). The formation of such 2D structures implies thesuccessful growth of SnO2 nanosheets on the graphene sheets,since only aggregation of SnO2 nanosheets with flower-likemorphology will be formed without the graphene support
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