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

•Nickel sulfide/N-doped graphene composite has been fabricated.•The N-doped graphene offers a continuous electrically conductive network.•The one-dimensional structure facilitates the diffusion of lithium ions and electrons.•The composite exhibits excellent lithium storage performance.

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 500 nm and diameter of 100 nm 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.

Graphical abstractNickel sulfide/N-doped graphene composite has been prepared through a simple one-step and in situ method using thiourea as the sulfur source and reducing agent. The nickel sulfide/N-doped graphene composite exhibits a relatively high reversible capacity and good cycling stability. The excellent 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. The presence of N atoms can increase the lithium ions storage capacity.Figure optionsDownload full-size imageDownload as PowerPoint slide