Ultrafine SnO₂ nanoparticles decorated onto graphene for high performance lithium storage

Ultrafine SnO₂ nanoparticles of 2-5 nm are controllably synthesized onto the surface of graphene via a simple one-pot hydrothermal approach without the addition of a surfactant. The resulting SnO₂-graphene nanocomposite shows a high level of homogeneous dispersion and high content of nano-sized SnO₂ (85%) loading. Such unique features of the SnO₂-graphene nanocomposite can not only buffer efficiently the volume change of SnO₂ during charge-discharge processes, but also facilitate fast diffusion of lithium ions in SnO₂ and the transport of electrons in graphene when it is used as an anode material for lithium storage. As a result, the ultrafine SnO₂-graphene nanocomposite exhibits a very high reversible capacity of 1037 mA h g^-1, excellent capacity retention of 90% over 150 cycles, and good high-rate capability. Combined with the other advantages of easy synthesis, low-cost, environment friendliness and high yield, the SnO₂-graphene nanocomposite could be a promising anode material for lithium ion batteries.