LAUSR

In this work, we proposed a facile template-sacrificing method to prepare bowl-like silicon@reduced graphene oxide (Si@rGO) hybrids as high performance anode for lithium ions battery (LIB). Uniform SiO2 spheres were initially synthesized and wrapped by GO, forming 3D skeleton. After reduction and etching, Si nanoparticles were obtained and distributed on the flexible rGO layer evenly, resulting in bowl-like nanoarchitecture. Benefit from this novel structure, the volume change of Si could be confined during charge-discharge process. As a result, the Si@rGO anode exhibited high first discharge capacity of ～1890 mAh·g-1 with Coulombic efficiency of 90.79% at the current density of 0.1 A·g-1. After 100 cycles, a stable specific capacity of 450 mAh·g-1 achieved which is twice higher than that of pure Si nanospheres (208 mAh·g-1) and rGO (260 mAh·g-1). Moreover, when the current density increased to 1 A·g-1, the specific capacity of Si@rGO was obtained as 100 mAh·g-1, whereas it was 34 mAh·g-1 associating with Si nanospheres, demonstrating the advances of Si@rGO. By analysing the electrochemical behaviour, it is found that the outstanding LIB performance of Si@rGO is ascribed to the involvement of rGO which constructs the 3D nanoarchitecture that acts the buffer layer to stabilize the Si and promotes the Li+ diffusion as well as the conductivity of electrodes. This work highlighted the significance of microstructure on lithium ions storage performance of Si based nanocomposite.