Electrochemical property of NH4V3O8•0.2H2O flakes prepared by surfactant assisted hydrothermal method

NH4V3O8 center dot 0.2H(2)O is synthesized by sodium dodecyl sulfonate (SDS) assisted hydrothermal method and its electrochemical performance is investigated. The as-prepared material is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared (IR) spectrum, differential scanning calorimetry and thermal gravimetry (DSC/TG), cyclic voltammetry (CV), and charge-discharge cycling test. The results show a pure NH4V3O8 center dot 0.2H(2)O phase with flake-like morphology is obtained and the average flake thickness is about 150 nm. The NH4V3O8 center dot 0.2H(2)O electrode has a good lithium ion insertion/extraction ability with the highest discharge capacity of 225.9 mAh g(-1) during 1.8-4.0V versus Li at the constant current density of 15 mA g(-1). After 30 cycles, it still maintains a high discharge capacity of 209.4 mAh g(-1), demonstrating good cyclic stability. Interestingly, at the discharge process a new (NH4)LixV3O8 center dot 0.2H(2)O compound is formed due to the new lithium ion from lithium metal anode. (C) 2010 Elsevier B.V. All rights reserved.