Fe3O4@C-500 anode derived by commercial ammonium ferric citrate for advanced lithium ion batteries

Abstract

Magnetite (Fe3O4) has become a potential anode material in lithium ion batteries (LIBs) because of its high theoretical capacity and low cost, but is impeded for application by its low conductivity and large volume change during cycling. Herein, the Fe3O4@C-500 composite was fabricated via the one-step pyrolytic carbonization of commercial ammonium ferric citrate (AFC), which is simple and environmentally friendly. As an anode in LIBs, the Fe3O4@C-500 electrode shows superior specific capacity, long cycling stability and excellent rate performance. Such remarkable performance can be attributed to the formation of the architecture with carbon (C) matrix, not only buffering the volume change and inhibiting the aggregation of internal Fe3O4 nanoparticles during (de)lithiation, but also elevating the electron conductivity. In situ X-ray diffraction (XRD) results demonstrate that the (de)lithiated mechanism of the Fe3O4@C-500 electrode involves a full electrochemically-driven amorphization upon cycling. Furthermore, the full cell assembled with Fe3O4@C-500 and LiFePO4 (LFP) electrodes shows outstanding electrochemical performance, demonstrating its practical energy storage application.