Enhanced performance as a lithium-ion battery cathode of electrodeposited V_2O_5 thin films by e-beam irradiation

摘要

The influence of electron beam irradiation on the electrochemical properties of electrodeposited V_2O_5 thin films was investigated. V_2O_5 thin films were deposited electrochemically onto indium tin oxide-coated glass from an aqueous vanadyl sulfate hydrate (VOSO_4·nH_2O) solution using Pt and Ag/AgCl as the counter electrode and reference electrode, respectively. Electrodeposition was performed potentiostatically at 1.7 V vs. Ag/AgCl. Electrodeposited samples were then subjected to a 1-MeVelectron beam using an electron beam accelerator at the Korea Atomic Energy Research Institute. For comparison, a control sample was not irradiated with the electron beam. Crystallinity change before and after electron beam irradiation was investigated by X-ray diffraction and the oxidation state of vanadium determined by X-ray photoelectron spectroscopy. Scanning electron microscopy was utilized to examine surface morphology. It was observed that electron beam irradiation altered the oxidation state of vanadium and increased crystallinity. Significant morphological changes of V_2O_5 thin films were also observed with electron beam irradiation. Cyclic voltammetry was employed to evaluate the electrochemical properties of the synthesized V_2O _5 films in terms of their application as electrodes of lithium-ion battery. Compared with the control sample, which was not irradiated with an electron beam, the electron beam-irradiated V_2O_5 specimens showed much higher capacitance.