▎ 摘　　要

A well-organized flexible composite of nitrogen-doped graphene-Fe3O4 (N-G-Fe3O4) is successfully synthesized through a green and facile chemical method. The half cells based on the synthesized N-G-Fe3O4 composite exhibit a reversible specific capacity approaching about 800 mA h g(-1), after 100 cycles at a current density of 100 mA g(-1). For the composite, the graphene plays a flexible confinement function to encapsulate Fe3O4 particles, accommodating the volume change and preventing the agglomeration of Fe3O4 nanoparticles. Furthermore, the nitrogen doping can greatly improve the electrical conductivity of graphene, and decrease the energy barrier for Li ion penetration and effectively modify the surface chemistry at the anode/ electrolyte interface to form a stable solid electrolyte interface (SEI) layer. As a result, this unique N-G-Fe3O4 composite can dramatically improve the cycling performance and rate capacity as an anode material for lithium ion batteries.