An easy and eco-friendly method to prepare reduced graphene oxide with Fe(OH)2 for use as a conductive additive for LiFePO4 cathode materials

We developed a green and low cost method to reduce graphene oxide (GO) using Fe(OH)(2) in a protective nitrogen atmosphere in only 15 min at room temperature. The presence of reduced graphene oxide (RGO) was confirmed by X-ray diffraction, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. It was revealed that Fe(OH)(2), as a reducer, can effectively remove a significant fraction of the oxygen-containing functional groups of GO in this one-step reduction. Considering the analysis results, the reduction mechanism for the synthesis of RGO using Fe(OH)(2) was proposed. With the aid of the conductive RGO additive, the poorly conductive LiFePO4 showed a good rate performance of 96.7 mA h g(-1) at 20 C, as well as an excellent cycling stability. In addition to being environmentally friendly, this time-saving approach was also simple and inexpensive, suggesting the possibility of the large-scale production of RGO, and facilitating the use of graphene-based materials for electrochemical energy storage.