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Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications

Dissertation (MSc)--University of Pretoria, 2017.

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Other Authors: Manyala, Ncholu I.
Format: Thesis
Language:English
Published: University of Pretoria 2018
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access_status_str Open Access
author2 Manyala, Ncholu I.
author_browse Manyala, Ncholu I.
author_facet Manyala, Ncholu I.
collection Thesis
dc_rights_str_mv © 2018 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc)--University of Pretoria, 2017.
format Thesis
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:38:18.923Z
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provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2018
publishDateRange 2018
publishDateSort 2018
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/65942 Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications Manyala, Ncholu I. u12263992@tuks.co.za Rantho, Mologadi Nkiyasi UCTD Dissertation (MSc)--University of Pretoria, 2017. Due to an urgent need for efficient, clean, and sustainable sources of energy, as well as new technologies associated with energy conversion and storage, the most effective and practical technologies for electrochemical energy conversion and storage are batteries, fuel cells, and electrochemical supercapacitors. In recent years, there have been a large number of research articles and technical reports on the development of electrochemical supercapacitors, motivated by their low energy density and high production cost. Consequently, research focus in supercapacitors is on improving the energy density (i.e. 5-8Wh kg?1) without compromising its high power density (i.e. 5-30 kW kg?1). In this work, the electrochemical properties of both vanadium disulfide (VS2) and carbonized iron cations adsorbed onto polyaniline (C-Fe/PANI) electrode materials were investigated for supercapacitor applications. The VS2 nanosheets electrode material was successfully synthesized by the hydrothermal method, and the C-Fe/PANI electrode material was directly synthesized on a current collector by pyrolysis of the iron-PANImixture coated on nickel foam in a tube furnace under the N2 atmosphere. The structural and morphological characterization of the as-synthesized electrode materials was carried out using X-ray diffraction (XRD), Raman spectrometer, Fourier transforminfrared (FT-IR) spectrometer, scanning electronmicroscopy (SEM), energy-dispersive X-ray spectrometer (EDS), transmission electronmicroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The electrochemical behavior of the C-Fe/PANI electrode was analyzed in both positive and negative potential window in a three-electrode cell configuration using 6 M KOH electrolyte, and thereafter, a C-Fe/PANI symmetric device was successfully fabricated. The C-Fe/PANI symmetric device was found to perform at a high cell voltage of 1.65 V in 6 M KOH. At a current density of 0.5 A g?1, this device exhibited a maximum energy and power densities of 41.3 Wh kg?1 and 231.9 W kg?1 respectively. The device further showed excellent cycling stability with capacity retention of 72% at a current density of 5 A g?1 over 10 000 galvanostatic charge-discharge cycles. To further evaluate the electrochemical performance of C-Fe/PANI with a metal disulfide material (VS2), a hybrid (asymmetric) device was successfully fabricated using VS2 nanosheets as the positive electrode and C-Fe/PANI as a negative electrode. Similarly, the electrochemical behavior of each working electrode was analyzed in a three-electrode cell configuration using 6 M KOH electrolyte, and thereafter, a hybrid (asymmetric) device was successfully fabricated using VS2 nanosheets as the positive electrode and C-Fe/PANI as a negative electrode. The fabricated VS2//C-Fe/PANI asymmetric device was found to perform at a high cell voltage of 1.7 V in 6 M KOH. At a current density of 2 A g?1, this device exhibited high energy and power densities of 27.8 Wh kg?1 and 2991.5 W kg?1 respectively. In addition, a VS2//C-Fe/PANI device showed excellent cycling stability with 95% capacity retention over 10 000 galvanostatic charge-discharge cycles at a current density of 5 A g?1. Physics MSc Unrestricted 2018-07-25T09:01:06Z 2018-07-25T09:01:06Z 2018/04/18 2017 Dissertation Rantho, MN 2017, Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/65942> A2018 http://hdl.handle.net/2263/65942 en © 2018 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications
title Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications
title_full Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications
title_fullStr Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications
title_full_unstemmed Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications
title_short Synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high-performance supercapacitor applications
title_sort synthesis and characterization of vanadium disulfide nanosheets and carbonized iron cations adsorbed onto polyaniline for high performance supercapacitor applications
topic UCTD
url http://hdl.handle.net/2263/65942