Sn/SnO_x-loaded uniform-sized hollow carbon spheres on graphene nanosheets as an anode for lithium-ion batteries

To meet the increasing demands for large-scalable application required high capacity and energy density, Sn-based materials as a promising anode for lithium-ion batteries have been widely studied. In this work, a carbon nanostructure of uniform-sized hollow carbon spheres on a graphene nanosheet was prepared by a facile synthesis process. The obtained nanostructure has numerous uniform-sized hollow carbon spheres with a diameter of ∼20 nm attached on graphene nanosheets, and mass production is considerably easy. Then, Sn/SnO_x was loaded into the carbon nanostructure by a typical melt diffusion process, and its electrode delivers the high rate capability of 290.0 mA g⁻¹ at 3.0 A g⁻¹ and the good cyclability of 284.1 mA h g⁻¹ after 1000 cycles at 1.0 A g⁻¹. The excellent electrochemical performance is attributed to the unique carbon nanostructure, which mitigates the volume expansion of Sn by the physical barrier of uniform-sized hollow carbon spheres and enables Li-ions or electrons to easily move by the improving electrical conductivity during discharge/charge process. Thus, the Sn loaded nanocomposite is expected to be a promising anode material for lithium-ion batteries.