Browsing by Author "Vinayraj, S."

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    High stable zinc tungstate electrode for electrochemical supercapacitor
    (American Institute of Physics Inc. subs@aip.org, 2020) Dhanush, P.C.; Brijesh, K.; Vinayraj, S.
    This paper aims to develop a way for synthesising Zinc Tungstate (ZnWO4) by Microwave method. Which is simpler easier and better than hydrothermal synthesis. Formation of the crystal microstructures were verified with the aid of Powder X-Ray Diffraction (XRD), and further, morphologies were investigated upon using Field Emission Scanning Electron Microscope (FESEM). The implications in the energy storage devices were examined by preparing a pseudo capacitor. The electrochemical characteristics were analysed by using three-electrode system and its performance was evaluated with the assistance of Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The result presented the specific capacitance as 79 Fg-1 for a scan rate of 1mVs-1. The ZnWO4 as an active material retains 96.52% stability up to 1000 cycles. A significant increase in the impedance for lower frequencies can be observed for the material after 1000 cycles when compared to that of the first cycle. © 2020 Author(s).
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    Monoclinic Wolframite ZnWO4/SiO2 nanocomposite as an anode material for lithium ion battery
    (Elsevier B.V., 2020) Brijesh, K.; Dhanush, P.C.; Vinayraj, S.; Nagaraja, H.S.
    Herein, we report the preparation and characterization of the ZnWO4 and ZnWO4/SiO2 nanocomposite. The ZnWO4/SiO2 nanocomposite exhibits 570 mAh g?1 discharge capacity and 314 mAh g?1 charge capacity at 10 mA g?1 for the primary cycle. The increasing amount of SiO2 in the ZnWO4/SiO2 nanocomposite increases the overall performance of the composite. The synergetic effect between the ZnWO4 and SiO2 enhances the rate capability, specific capacity, cycle stability and coloumbic efficiency of the composite. The good electrochemical performance of ZnWO4/SiO2 nanocomposite makes it a promising anode for Lithium ion battery. © 2020 Elsevier B.V.
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    ZnWO4/SnO2@r-GO nanocomposite as an anode material for high capacity lithium ion battery
    (Elsevier Ltd, 2020) Brijesh, K.; Vinayraj, S.; Dhanush, P.C.; Bindu, K.; Nagaraja, H.S.
    Lithium ion battery (LIB) is widely used energy storage device. Herein, we report the preparation of ZnWO4/SnO2 nanocomposite and ZnWO4/SnO2@r-GO nanocomposite via solvothermal method. The structural, elemental and morphological properties of the prepared samples are characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), high-resolution transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) measurements, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. The prepared samples are tested as an anode for LIB. The ZnWO4/SnO2 (5%) nanocomposite delivers initial discharge capacity of 882 mAh g?1 at a current density of 100 mA g?1, while, the specific capacity increases with the increase of SnO2 upto 10% tested in present case. Further, ZnWO4/SnO2@r-GO nanocomposite exhibits a discharge capacity of 1486 mAh g?1 which is higher than that of ZnWO4/SnO2 nanocomposite. In addition, after 500 cycles ZnWO4/SnO2@r-GO nanocomposite exhibits 89.8% cycle life and 98% of discharge capacity retention. These results indicate that, ZnWO4/SnO2@r-GO nanocomposite is a promising anode material for LIB. © 2020 Elsevier Ltd