Preparing graphene-based anodes with enhanced electrochemical performance for lithium-ion batteries

The present study investigates the structural and chemical factors contributing to the performance of graphene oxide anode materials produced by Hummers (GO(H)) and Tour (GO(T)) for lithium-ion batteries (LIBs). The GO synthesized by these methods were studied using FTIR and Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Thorough electrochemical analysis including cycling stability, rate capability, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were also conducted. We show that the improved performance of GO(T)(almost twice) compared with that of GO(H)is due to the key role of the protective agent (H3PO4) in reducing/inhibiting the hole formation during the synthesis of the GO(T)surface which in turn results in superior cycling performance over the GO(H). The results and proposed mechanism presented in this work elucidates the role of structural factors and defects in preparing graphene-based anodes with enhanced electrochemical efficiency.