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Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications

Dissertation (MSc (Chemical Technology))--University of Pretoria, 2020.

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Other Authors: Manyala, Ncholu I.
Format: Thesis
Language:English
Published: University of Pretoria 2021
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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 © 2019 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 (Chemical Technology))--University of Pretoria, 2020.
format Thesis
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:37:59.731Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2021
publishDateRange 2021
publishDateSort 2021
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/78100 Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications Manyala, Ncholu I. vianneykitenge@gmail.com Van Heerden, Xandra Kitenge, Vianney Ngoyi UCTD enhancing supercapacitors energy Ternary NiCoMn hydroxides Graphene foam Electrochemical properties Energy storage Engineering, built environment and information technology theses SDG-07 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-13 Dissertation (MSc (Chemical Technology))--University of Pretoria, 2020. Sustainable, environmentally friendly, and renewable energy sources are urgently needed as concerns about carbon emissions and the depletion of fossil fuels are becoming worrying. It is vital to explore cost-effective and environmentally sustainable energy sources to ensure adequate provision for the ever-increasing energy demand. Supercapacitor devices enable storage of energy and its delivery at high power over a short period. These devices have the advantage of being manufactured at low cost, being safe to use, and having a long-life cycle. This study investigated the effect of incorporating a carbon-based material (graphene foam) within a ternary transition-metals hydroxide (Nickel, Cobalt, and Manganese) to obtain its optimal electrochemical properties for supercapacitors applications. It involved a low-cost and environmentally sustainable synthesis method whereby a constant quantity of the ternary metal hydroxides (NiCoMnTH) was loaded onto various amounts of graphene foam (GF). Typical energy storage characterisation techniques were performed on the synthesised material. The physical characterisation provided results regarding the structural, morphological and surface particularities of the different nanostructured materials. The electrochemical characterisation (EC) allowed the evaluation of the materials' electrochemical behaviours and performances. The EC results also revealed the optimised composite, which demonstrated outstanding electrochemical performances. The integration of graphene foam within the pristine material enhanced its surface area improving its specific capacity to about 178,6 mAh g-1. This specific capacity was close to the triple of the initial value having a specific capacity value equivalent to 76,2 mAh g-1 when evaluated in the same configuration and under the same settings. The improved nanomaterial was then utilised as a positive electrode material for the design of a novel hybrid device. The hybrid device was assembled with the optimised material (NiCoMnTH/GF) on the positive end and activated carbon on the negative end. The device demonstrated a sustaining specific capacity of 23,4 mAh g-1at a specific current of 0,5 A g-1. The device also yielded sustaining specific energy and power densities of values of 22,32 Wh kg-1 and 439,7 W kg-1 respectively at the same specific current. The battery-supercapacitor materials combination developed a synergetic effect on the electrochemical properties, thereby enhancing the specific energy and power densities. After a 15000 cycles stability test, the device displayed an outstanding Coulombic efficiency of 99,9 % and capacity retention of 80 % within a potential range of 1,6 V at a specific current of 3 A g−1. These results have demonstrated the prodigious electrochemical potentials of the as-prepared novel nanomaterial and its capability to be utilised as a positive electrode for energy storage applications. National Research Foundation mi2026 Chemical Engineering MSc (Chemical Technology) Unrestricted SDG-07: Affordable and clean energy SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production SDG-13: Climate action 2021-01-22T10:42:57Z 2021-01-22T10:42:57Z 2021 2020 Dissertation * A2021 http://hdl.handle.net/2263/78100 en © 2019 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
enhancing supercapacitors energy
Ternary NiCoMn hydroxides
Graphene foam
Electrochemical properties
Energy storage
Engineering, built environment and information technology theses SDG-07
Engineering, built environment and information technology theses SDG-09
Engineering, built environment and information technology theses SDG-12
Engineering, built environment and information technology theses SDG-13
Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications
title Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications
title_full Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications
title_fullStr Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications
title_full_unstemmed Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications
title_short Enhancing the electrochemical properties of a Nickel-CobaltManganese ternary hydroxide electrode material using graphene foam for supercapacitors applications
title_sort enhancing the electrochemical properties of a nickel cobaltmanganese ternary hydroxide electrode material using graphene foam for supercapacitors applications
topic UCTD
enhancing supercapacitors energy
Ternary NiCoMn hydroxides
Graphene foam
Electrochemical properties
Energy storage
Engineering, built environment and information technology theses SDG-07
Engineering, built environment and information technology theses SDG-09
Engineering, built environment and information technology theses SDG-12
Engineering, built environment and information technology theses SDG-13
url http://hdl.handle.net/2263/78100