Porous Fe3O4 hollow spheres with chlorine-doped-carbon coating as superior anode materials for lithium ion batteries

In this study, chlorine-doped carbon-encapsulated porous Fe3O4 hollow spheres (PH-Fe3O4@C/Cl) are fabricated by a facile and controllable route. The unique structure of the porous Fe3O4 hollow spheres could facilitate lithium ion transport by reducing the diffusion distance, and provide full utilization upon contact with the electrolyte. The C/Cl film on the Fe3O4 electrode material surfaces could not only improve the electrical conductivity, but also prevent the drastic volume expansion and the Fe3O4 nanoparticle aggregation induced in the charge and discharge process. As anticipated, the PH-Fe3O4@C/Cl could deliver several superior electrochemical performances. For example, the reversible capacities were 920 mA h g(-1) at 0.1 C, 855 mA h g(-1) at 0.2 C, 650 mA h g(-1) at 0.5 C, 550 mA h g(-1) at 1.0 C and 420 mA h g(-1) at 2.0 C, respectively. We anticipated this synthetic approach would have great potential in other nanomaterials with large volume excursions and poor conductivity.