Electrochemical energy storage in a β-Na0.33V2O5 nanobelt network and its application for supercapacitors
Lee, Pooi See
Date of Issue2010
School of Materials Science and Engineering
We report a nanostructured oxide pseudocapacitor electrode utilizing a sodium-doped vanadium oxide (β-Na0.33V2O5) nanobelt network with a three dimensional framework crystal structure, which has been successfully synthesized under mild hydrothermal conditions and heat treatment. Cyclic voltammetry, galvanostatic charge-discharge and cycling tests have been carried out on the nanobelt network in 1 M LiClO4/propylene carbonate (PC) electrolyte for a 1 V potential window. A high specific capacitance of 320 F g−1 at 5 mV s−1 scan rate has been achieved with two sets of redox peaks being identified, corresponding to the half occupancy at M3 and M2 intercalation sites along the tunnel in the β-Na0.33V2O5 crystal lattice. The β-Na0.33V2O5 nanobelt electrode is able to deliver a high energy density of 47 W h kg−1 at a high power density of 5 kW kg−1. Slight degradation in energy density at high power density has been observed. This can be attributed to the charge storage in the nanobelt network which is dominated by the fast surface dependent reaction. Superior cycling stability, with only 34% degradation in specific capacitance, is observed in the β-Na0.33V2O5 nanobelts after 4000 cycles. The results clearly indicate the promising potential of these doped vanadium oxide electrodes for electrochemical energy storage devices.
Journal of materials chemistry
© 2010 The Royal Society of Chemistry. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of Materials Chemistry , The Royal Society of Chemistry. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1039/c0jm00652a].