One-step synthesis of nickel sulfide/N-doped graphene composite as anode materials for lithium ion batteries

Abstract

Nickel sulfide/N-doped graphene composite as high performance anode materials has been synthesized through a simultaneous hydrothermal method. The morphology, structure and electrochemical performance of nickel sulfide/N-doped graphene composite were investigated by field emission scanning electron microscopy, transmission electron microscope, X-ray diffraction, Raman spectra, Fourier transform infrared spectra, X-ray photoelectron spectroscopy and electrochemical measurements. The nickel sulfide with a length of about 500nm and diameter of 100nm clung to the N-doped graphene matrix. The nickel sulfide/N-doped graphene composite exhibits a relatively high reversible capacity and good cycling stability as anode materials for lithium ion batteries. The good electrochemical performance can be attributed to N-doped graphene, which improves the electronic conductivity of composite and suppresses the volume effect as elastic matrix. The one-dimensional structure of nickel sulfide facilitates the diffusion of lithium ions and electrons.