Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance

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dc.contributor.advisorConrad, Olafen_ZA
dc.contributor.advisorHussain, Nabeelen_ZA
dc.contributor.authorCrymble, Gregory Aen_ZA
dc.date.accessioned2015-05-18T14:26:06Z
dc.date.available2015-05-18T14:26:06Z
dc.date.issued2014en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractPolymer electrolyte membrane (PEM) fuel cells are promising clean energy alternatives to non - sustainable fossil fuels. During fuel cell operation, external humidification of reactant gases is typically required in order to increase PEM conductivity for improved performance. However, the use of external humidification is costly and increases system complexity. Recently it has been found that by including a cathode microporous layer (MPL) in the membrane electrode assembly (MEA) , performance under dry conditions (no external humidification) can be significantly improved . However, the precise function of the MPL is not well understood and therefore there is little theoretical basis to optimisation of physical properties. One possible reason for this lack of understanding is the absence of a well-established fabrication, characterization and electrochemical testing methodology for MPL research. In particular, current research places little emphasis on the effect of MEA variance on the uncertainty in MPL electrochemical performance results. In this study a methodology is developed for fabricating, characterizing and testing MPLs to accurately correlate physical properties with in-situ electrochemical performance. MPLs of two significantly different thicknesses (approximately 20 and 50 μm in the thickest regions) were fabricated in - house using a doctor blade method and varying the ink composition. The pore structure and thickness of MPLs were characterized by mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM) and X-ray micro computed tomography (μCT).en_ZA
dc.identifier.apacitationCrymble, G. A. (2014). <i>Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Catalysis Research. Retrieved from http://hdl.handle.net/11427/12831en_ZA
dc.identifier.chicagocitationCrymble, Gregory A. <i>"Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Catalysis Research, 2014. http://hdl.handle.net/11427/12831en_ZA
dc.identifier.citationCrymble, G. 2014. Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Crymble, Gregory A AB - Polymer electrolyte membrane (PEM) fuel cells are promising clean energy alternatives to non - sustainable fossil fuels. During fuel cell operation, external humidification of reactant gases is typically required in order to increase PEM conductivity for improved performance. However, the use of external humidification is costly and increases system complexity. Recently it has been found that by including a cathode microporous layer (MPL) in the membrane electrode assembly (MEA) , performance under dry conditions (no external humidification) can be significantly improved . However, the precise function of the MPL is not well understood and therefore there is little theoretical basis to optimisation of physical properties. One possible reason for this lack of understanding is the absence of a well-established fabrication, characterization and electrochemical testing methodology for MPL research. In particular, current research places little emphasis on the effect of MEA variance on the uncertainty in MPL electrochemical performance results. In this study a methodology is developed for fabricating, characterizing and testing MPLs to accurately correlate physical properties with in-situ electrochemical performance. MPLs of two significantly different thicknesses (approximately 20 and 50 &#956;m in the thickest regions) were fabricated in - house using a doctor blade method and varying the ink composition. The pore structure and thickness of MPLs were characterized by mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM) and X-ray micro computed tomography (&#956;CT). DA - 2014 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2014 T1 - Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance TI - Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance UR - http://hdl.handle.net/11427/12831 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/12831
dc.identifier.vancouvercitationCrymble GA. Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Catalysis Research, 2014 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/12831en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentCentre for Catalysis Researchen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherCatalysis Researchen_ZA
dc.titleTowards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performanceen_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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