Investigation of the Lithium Intercalation Behavior of Nanosheets of LiV3O8 in an Aqueous Solution

Abstract

Nanosheets of lithium vanadium oxide (LiV3O8) are synthesized using a citrate sol–gel combustion route. The physical characterizations are carried out by scanning and transmission electron microscopies (SEM and TEM) and X-ray diffraction (XRD) measurements. Compact nanosheets of the active material are observed by SEM and TEM. XRD data indicate that the prepared nanosheets present pure phase of monoclinic LiV3O8 with p21/m symmetry. The kinetics of electrochemical intercalation of lithium ion into the nanosheets are investigated by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) studies with special emphasis on the application potential as an anodic material for aqueous rechargeable lithium batteries. CV studies of the nanosheets at a slow scan rate of 0.3 mV s–1 between +250 and −700 mV vs Ag/AgCl demonstrate that nanosheets of LiV3O8 represent well-defined reversible peaks. The nonlinear chemical diffusion of lithium ion into the nanosheets is explored by EIS. The results are discussed on the basis of an equivalent circuit, distinguishing the kinetics of lithium intercalation. The fitting results are in good agreement with the experimental results, and the kinetic parameters of lithium intercalation are obtained with the proposed equivalent circuit. The changes of kinetic parameters of lithium intercalation with potential are also discussed in detail.