Abstract:Graphene/SnO2 (GS) composites were synthesized from graphene oxide and SnCl2 by microwave hydrothermal method. Using ammonium persulfate as initiator, the coating structure of Si@PPy (SP) was prepared by in situ oxidation polymerization of pyrrole on the surface of Si powders. Graphene/SnO2/Si@PPy (GSSP) composites were prepared by microwave hydrothermal assembly method. The morphology and structure of GS, SP and GSSP were characterized by SEM, TEM, XRD, Raman and BET. The half-cells were assembled with GSSP composite as anode, and then the electrochemical properties were tested, such as rate performance, cyclic performance, CV and EIS. The results showed that the GSSP composite had excellent rate performance. At a current density of 100 mA/g, the average specific capacity of discharge and charge is 948.44 mAh/g and 869.63 mAh/g, respectively. Under the current density of 1000 mA/g, the specific capacity retention rate after 400 cycles of discharge and charge was up to 90.69% and 89.34%.