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Electrolytes for redox flow battery systems
Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : University of Stellenbosch
2010
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| _version_ | 1867614082525298688 |
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| access_status_str | Open Access |
| author | Modiba, Portia |
| author2 | Crouch, Andrew M. |
| author_browse | Crouch, Andrew M. Modiba, Portia |
| author_facet | Crouch, Andrew M. Modiba, Portia |
| author_sort | Modiba, Portia |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/3999 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:46:22.874Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2010 |
| publishDateRange | 2010 |
| publishDateSort | 2010 |
| publisher | Stellenbosch : University of Stellenbosch |
| publisherStr | Stellenbosch : University of Stellenbosch |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/3999 Electrolytes for redox flow battery systems Modiba, Portia Crouch, Andrew M. University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. Electrolytes Redox flow battery Cyclic voltammetry Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010. Electrochemical behaviour of Ce, Fe, Cr,V and Mn in the presence of DTPA, EDTA, EDDS, NTA ligands were investigated by using cyclic voltammetry, a rotating disc electrode and electrochemical impedance spectroscopy for use in redox flow battery (RFB) systems. RFB is currently used for energy storage, the vanadium, which is used in most of the RFB’s, however suffers from species crossover and sluggish reactions, which limit the lifetime of the battery. These various ligands and metal complexes mentioned above where all examined to identify the suitable and favoured electrolyte that can be used for a RFB system. Kinetic parameters such as potential, limiting current, transfer coefficient, diffusion coefficients, and rate constants were studied. RDE experiments confirmed that the parameters measured by CV are similar under hydrodynamic conditions and can be used to determine the kinetic parameters of the redox couples. The use of DTPA as a ligand for complexation of Ce(IV) gave more favourable results compared to other ligand with various metal complexes used in this study [1-3]. The results of kinetic studies of Ce(IV)–DTPA complex shows promise as an electrolyte for a redox flow battery. The separation of V(IV)/(V), Fe (III)/(IV),Cr(III)/(IV),Mn (III)/(IV) and Ce(III)/(IV) with various ligands (EDTA, EDDS, NTA and DTPA) were also investigated using capillary electrophoresis. To understand the speciation of these metal complexes as used in this study and particularly the vanadium, for the reason that it has a complicated (V) oxidation state. The charge/discharge performance of all electrolytes used in this work was determined and a high voltage achieved when Ce-DTPA was used, and it is compared to that of the vanadium electrolyte currently in use. This was evaluated with systems studied previously. Therefore, Ce-DTPA will be a suitable electrolyte for redox flow battery systems. Doctoral 2010-02-23T16:28:19Z 2010-08-13T13:11:05Z 2010-02-23T16:28:19Z 2010-08-13T13:11:05Z 2010-02-23T16:28:19Z 2010-03 Thesis http://hdl.handle.net/10019.1/3999 en University of Stellenbosch application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | Electrolytes Redox flow battery Cyclic voltammetry Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science Modiba, Portia Electrolytes for redox flow battery systems |
| title | Electrolytes for redox flow battery systems |
| title_full | Electrolytes for redox flow battery systems |
| title_fullStr | Electrolytes for redox flow battery systems |
| title_full_unstemmed | Electrolytes for redox flow battery systems |
| title_short | Electrolytes for redox flow battery systems |
| title_sort | electrolytes for redox flow battery systems |
| topic | Electrolytes Redox flow battery Cyclic voltammetry Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science |
| url | http://hdl.handle.net/10019.1/3999 |
| work_keys_str_mv | AT modibaportia electrolytesforredoxflowbatterysystems |