LAUSR

Abstract Herein, yolk-double shell Fe3O4@C@C nanospheres (YDS-FCCNs) were designed and synthesized via solvothermal and following heat management. The as-obtained yolk-shell morphology consisted by two parts: one for the Fe3O4@C nanosphere (diameter about 100 nm) as core, and the other for nitrogen-doped carbon (thickness about 50 nm) as the shell. The YDS-FCCNs composite exhibited preeminent cycling stability of 780 mAh/g at 0.5 A/g after 500 cycles, even at higher current density of 2 A/g, it still retained a reversible capacity of 559 mAh/g after 500 cycle. The good electrochemical performance could attribute to the following factors: First, the hierarchical double carbon shell could prevent the agglomeration of the Fe3O4, meanwhile largely enhance the electrical conductivity. Second, the synergistic effects for multilayered structure and atomic doping could improve the comprehensive electrochemical performance.