title: Electrochemical codeposition of vanadium oxide and polypyrrole for high-performance supercapacitor with high working voltage.
abstract: Electrochemical codeposition of vanadium oxide (V2O5) and polypyrrole (PPy) is conducted from vanadyl sulfate (VOSO4) and pyrrole in their aqueous solution to get V2O5-PPy composite, during which one-dimensional growth of polypyrrole (PPy) is directed. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) are used to characterize the composite, while scanning electron microscopy (SEM) is used to investigate their morphologies. Cyclic voltammetry (CV), chronopotentiometry (CP) for galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) are used to study electrochemical activities and pseudocapacitive properties of the composite. The influences of VOSO4 to pyrrole ratio in the electro-codeposition solution on morphologies and pseudocapacitive properties of the composite are discussed. Due to the organic-inorganic synergistic effect, V2O5-PPy composite exhibits good charge-storage properties in a large potential window from -1.4 to 0.6 V vs SCE, with a specific capacitance of 412 F/g at 4.5 mA/cm(2). A model supercapacitor assembled by using the V2O5-PPy composite as the electrode materials displays a high operating voltage of 2 V and so a high energy density of 82 Wh/kg (at the power density of 800 W/kg).
authors.affiliation: Department of Chemistry, Northeastern University , Shenyang, 110819, China.
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Bai
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Bian
authors.forename: Yu
authors.initials: Y
authors.lastname: Song
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Liu