Sonochemistry-enabled uniform coupling of SnO 2 nanocrystals with graphene sheets as anode materials for lithium-ion batteries

Abstract

SnO 2 /graphene nanocomposite was successfully synthesized by a facile sonochemical method from SnCl 2 and graphene oxide (GO) precursors. In the sonochemical process, the Sn 2+ is firstly dispersed homogeneously on the GO surface, then in situ oxidized to SnO 2 nanoparticles on both sides of the graphene nanosheets (RGO) obtained by the reduction of GO under continuous ultrasonication. Graphene not only provides a mechanical support to alleviate the volume changes of the SnO 2 anode and prevent nanoparticle agglomeration, but also serves as a conductive network to facilitate charge transfer and Li + diffusion. When used as a lithium ion battery (LIB) anode, the SnO 2 /graphene nanocomposite exhibits significantly improved specific capacity (1610 mA h g -1 at 100 mA g -1 ), good cycling stability (retaining 87% after 100 cycles), and competitive rate performance (273 mA h g -1 at 500 mA g -1 ) compared to those of bare SnO 2 . This sonochemical method can be also applied to the synthesis of other metal-oxide/graphene composites and this work provides a large-scale preparation route for the practical application of SnO 2 in lithium ion batteries.