Investigating the impact of nitrogen-doping on the characteristics and performance of reduced graphene oxide for lithium-ion batteries anode through experimental and theoretical study

Abstract

Recently, graphene-based materials have gained widespread attention due to their remarkable electronic characteristics, which make them ideal for use in a broad range of energy storage applications such as lithium-ion battery (LIB). Despite the potential benefits of graphene-based materials, the process of creating them in a cost-efficient manner remains difficult. Herein, we developed nitrogen-doped reduced graphene oxide (NRGO) through a one-step thermal reduction of graphene oxide (GO) and urea. We evaluated the structure and morphology of NRGO by using scanning electron microscopy (SEM), ultraviolet-visible light (UV–vis) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, which revealed a wrinkled, layered structure with 8.4 % nitrogen content. Moreover, we also compared the performance of RGO and NRGO as an anode for LIB through various electrochemical characterizations, i.e., cyclic voltammetry (CV), galvanostatic charge discharge (CD), and electrochemical impedance spectroscopy (EIS). The result indicates that NRGO provides 2.6 faster lithium diffusion compared to RGO. To gain insights into lithium migration pathways, density functional theory based nudged elastic band (DFT-NEB) simulations were performed. The results revealed the energy barrier of lithium migration in graphitic-NRGO is estimated to be 0.15 eV, and for its reverse reaction, a barrier of 0.22 eV is required. In conclusion, the NRGO synthesized through this relatively simple process displays a promising prospect for anode component in LIB and the reaction pathway simulation provides an important insight into the understanding of lithium migration on the NRGO surface and its optimization for LIB applications.