Electrochimica Acta, Vol.130, 800-804, 2014
The fabrication of Li3VO4/Ni composite material and its electrochemical performance as anode for Li-ion battery
Uniform Li3VO4 film was successfully grown on porous Ni foam, which shows good electrochemical performance as anode for Li-ion battery due to the improved reaction kinetics. The as-prepared Li3VO4/Ni electrode can deliver discharge and charge capacity of 379 and 378 mAh g(-1) after 100 cycles at a charge/discharge rate of 0.3 C. After various charge/discharge rates from 0.4 to 15 C, the discharge capacity of the Li3VO4/Ni electrode can restore to 404 mAh g(-1) when lowering the charge/discharge rate to 0.4 C. The reaction kinetics of the Li3VO4/Ni electrode was studied by cyclic voltammetry (CV) measurement at various scan rate and electrochemical impedance spectroscopy (EIS). Linear dependence between anodic/cathodic peak currents and the square root of scan rate suggests a lithium ion diffusion controlled mechanism of Li3VO4/Ni electrode in charge/discharge process, and the symmetrical slope of the two straight lines indicates a highly reversible lithiation/delithiation process. EIS measurements of the Li3VO4/Ni electrode show low and stable contact and charge-transfer resistances in cycling, suggesting highly stable charge transfer process and Li-ion diffusion coefficient. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords:Lithium vanadate;Lithium ion battery;Anode;Electrochemical reaction kinetics;Electrochemical reconstruction