Synthesis of 3D nitrogen-doped graphene/Fe3O4 by a metal ion induced self-assembly process for high-performance Li-ion batteries

We demonstrate the fabrication of three-dimensional nitrogen-doped graphene (3D N-G)/nanoparticle anode architectures consisting of 3D N-G networks and Fe3O4 nanoparticles. In such a hybrid structure, the N-G networks act as a buffer matrix to accommodate the volume change of Fe3O4, and the interconnected N-G sheets effectively prevent the aggregation of nanoparticles during cycling, both of which enable the structural integrity and electrochemical stabilization of such composite electrodes. Furthermore, the as-obtained porous nitrogen-doped hybrid materials promote efficient transport of both lithium ions and electrons upon charging/discharging, and also provide defect sites as Li+ active sites on the surface of N-G sheets. As a result, the hybrids exhibit much-improved lithium storage performance.