LAUSR

Abstract As a promising anode candidate for lithium-ion batteries (LIBs), SnO2-based material has been extensively investigated. However, its practical application is still hindered due to the inherent drawbacks of poor conductivity, severe volume expansion, and unavoidable agglomeration of active material during repeated discharge/charge process as well as formation of unstable solid electrolyte interface (SEI) layer. In this paper, the SnO2@carbon nanotube/reduced graphene oxide (SnO2@CNT/RGO) composite is rationally designed and fabricated, in which nano SnO2 nanoparticles (NPs, ~6 nm) are anchored onto three-dimensional (3D) conductive CNTs/RGO skeleton by first assembling SnO2 onto CNT and then entangling SnO2@CNT nanofibers in 3D graphene networks. The synergistic effect of CNT and RGO significantly increase the conductivity and prevent aggregation of active material. In addition, the mesopores structure constructed by CNT and RGO can accommodate the volume change of SnO2 NPs and form more stable SEI layer during repeated discharge/charge process. Therefore, the SnO2@CNT/RGO electrode exhibits not only more stable cycle performance but also more superior rate capacity. The discharge/charge specific capacity at 0.2 A g−1 is 1032/1022 mAh g−1 after 100 cycles. Even at high current density of 2.0 A g−1, it still maintains the discharge/charge capacity of 586/578 mAh g−1 after 200 cycles.