Degradation of the beta-alumina electrolyte in a zebra cell

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dc.contributor.advisorHutchings, Ronen_ZA
dc.contributor.advisorBall, Anthonyen_ZA
dc.contributor.authorVan Heerden, D Pen_ZA
dc.date.accessioned2016-03-14T07:01:52Z
dc.date.available2016-03-14T07:01:52Z
dc.date.issued1988en_ZA
dc.descriptionBibliography: pages 103-106.en_ZA
dc.description.abstractBeta-alumina solid electrolytes studied were subjected to charge and discharge cycles in a secondary, high energy density Na/beta-alumina/NaAlCl₄/FeCl₂ cell (known as the Zebra cell) at 250⁰ C. These electrolytes were studied by means of optical microscopy, as well as SEM and EDS analyses to est ablish possible failure modes. After cycling little discolouration, or impurity pickup was found to have occurred in the electrolyte. The forms of degradation of the beta-alumina electrolyte identified appeared to be a result of inherent flaws in the beta-alumina electrolyte tube, problems due to protracted storage of the tubes, or an apparent interfacial film on the cathode/electrolyte interface. A lead wetting agent was used in the cells to enhance the wetting of the beta-alumina electrolyte by the liquid Na. A study of the coating after cycling of the cell showed that the coating was adherent irrespective of the number of cycles completed. The coating did not appear to influence cracking of the electrolyte during cycling. Cracking of the beta-alumina electrolyte was found to have initiated from the Na/electrolyte interface. No evidence of crack initiation nor internal damage was found on the cathode/electrolyte interface. The cracks through the beta-alumina electrolyte wall were found to have sealed by the formation of a plug consisting largely of Na and Cl. On the basis of EDS analyses of the fracture surface of the sealed crack possible sealing mechanisms are proposed.en_ZA
dc.identifier.apacitationVan Heerden, D. P. (1988). <i>Degradation of the beta-alumina electrolyte in a zebra cell</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering. Retrieved from http://hdl.handle.net/11427/17666en_ZA
dc.identifier.chicagocitationVan Heerden, D P. <i>"Degradation of the beta-alumina electrolyte in a zebra cell."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 1988. http://hdl.handle.net/11427/17666en_ZA
dc.identifier.citationVan Heerden, D. 1988. Degradation of the beta-alumina electrolyte in a zebra cell. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Van Heerden, D P AB - Beta-alumina solid electrolytes studied were subjected to charge and discharge cycles in a secondary, high energy density Na/beta-alumina/NaAlCl₄/FeCl₂ cell (known as the Zebra cell) at 250⁰ C. These electrolytes were studied by means of optical microscopy, as well as SEM and EDS analyses to est ablish possible failure modes. After cycling little discolouration, or impurity pickup was found to have occurred in the electrolyte. The forms of degradation of the beta-alumina electrolyte identified appeared to be a result of inherent flaws in the beta-alumina electrolyte tube, problems due to protracted storage of the tubes, or an apparent interfacial film on the cathode/electrolyte interface. A lead wetting agent was used in the cells to enhance the wetting of the beta-alumina electrolyte by the liquid Na. A study of the coating after cycling of the cell showed that the coating was adherent irrespective of the number of cycles completed. The coating did not appear to influence cracking of the electrolyte during cycling. Cracking of the beta-alumina electrolyte was found to have initiated from the Na/electrolyte interface. No evidence of crack initiation nor internal damage was found on the cathode/electrolyte interface. The cracks through the beta-alumina electrolyte wall were found to have sealed by the formation of a plug consisting largely of Na and Cl. On the basis of EDS analyses of the fracture surface of the sealed crack possible sealing mechanisms are proposed. DA - 1988 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1988 T1 - Degradation of the beta-alumina electrolyte in a zebra cell TI - Degradation of the beta-alumina electrolyte in a zebra cell UR - http://hdl.handle.net/11427/17666 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/17666
dc.identifier.vancouvercitationVan Heerden DP. Degradation of the beta-alumina electrolyte in a zebra cell. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 1988 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/17666en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentCentre for Materials Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherElectrolytesen_ZA
dc.subject.otherElectrolyte solutionsen_ZA
dc.titleDegradation of the beta-alumina electrolyte in a zebra cellen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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