Enhanced electrochemical performance of multi-walled carbon nanotubes modified Li2FeSiO4/C cathode material for lithium-ion batteries

Graphical abstract: The multi-walled carbon nanotubes (MWCNTs) modified Li2FeSiO4/C composite is synthesized via a citric acid-based sol–gel method. The as-prepared Li2FeSiO4/C/MWCNTs electrode displays a remarkably enhanced high-rate performance and cycling stability because of the effective conducting network between the MWCNTs and the Li2FeSiO4/C particles. Highlights: •Nano-Li2FeSiO4/C/MWCNTs composite was successfully synthesized via a citric acid-based sol–gel method. •High conducting network were attained for Li2FeSiO4/C/MWCNTs. •The Li2FeSiO4/C/MWCNTs electrode can extract more than 1 mol Li+ at 0.1 C. •The as-prepared Li2FeSiO4/C/MWCNTs electrode displays a remarkably enhanced high-rate performance and cycling stability. -- Abstract: The multi-walled carbon nanotubes (MWCNTs) modified Li2FeSiO4/C composite is synthesized via a citric acid-based sol–gel method, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, galvanostatic charge/discharge measurements, cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) tests. The Li+ diffusion coefficient in Li2FeSiO4/C/MWCNTs is larger than that in Li2FeSiO4/C. Compared with Li2FeSiO4/C, Li2FeSiO4/C/MWCNTs electrode can extract more than 1 mol Li+ and exhibit better electrochemical performance with a high discharge capacity of 206.8 mA h g−1 in the second cycle, especially, an excellent high-rate capacity and cycle stability. The enhanced electrochemical performance is attributed to the reduced particle size and the high conducting network between the MWCNTs and the Li2FeSiO4/C particles