▎ 摘　　要

Monodispersed ferroferric oxide (Fe3O4) microspheres were prepared by a solvo-thermal method at first. They were coated with a thin layer of silica, and modified with amino groups. These updated microspheres were mixed with graphene oxide (GO) followed by a chemical reduction to yield Fe3O4-W-RGO. The sample was characterized with scanning electron microscopy (SEM) and transition electron microscopy (TEM). Fe3O4 microspheres (similar to 440 nm in diameter) are proved to be surface-coated by a SiO2 layer homogeneously to afford Fe3O4@SiO2 core-shell microspheres, tightly bound to reduced graphene oxide (RGO) nanosheets. From X-ray diffraction (XRD) patterns, Fe3O4 microspheres display good crystallinity and high purity. Results of electrochemical measurements indicate that Fe3O4-W-RGO sample can deliver an initial capacity of 1246 mAh/g at 0.1C rate over 0.01 V-3.00 V (vs. Li+/Li), and retain 830 mAh/g after 100 cycles. Even at 2C rate, it can still deliver a capacity of 484 mAh/g. All results suggest that Fe3O4-W-RGO composite material possesses good rate capability and cycling performance when used as anode material for lithium-ion batteries.