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

Abstract

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.