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dc.contributor.authorZhao, Teng
dc.date.accessioned2018-05-10T10:28:42Z
dc.date.available2018-05-10T10:28:42Z
dc.date.issued2018-05-02
dc.date.submitted2017-11-17
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/275684
dc.description.abstractIssues with the dissolution and diffusion of polysulfides in liquid organic electrolytes hinder the advance of lithium–sulfur (Li-S) batteries for next generation energy storage. To trap and re-utilize the polysulfides, brush-like, zinc oxide (ZnO) nanowires based interlayers were prepared ex-situ using a wet chemistry method and were coupled with a sulfur/multi-walled carbon nanotube (S/MWCNT) composite cathode. The cell with this configuration showed a good cycle life at a high current rate ascribed to (a) a strong interaction between the polysulfides and ZnO nanowires grown on conductive substrates; (b) fast electron transfer and (c) an optimized ion diffusion path from a well-organized nanoarchitecture. A praline-like flexible interlayer consisting of titanium oxide (TiO2) nanoparticles and carbon (C) nanofiber was further prepared in-situ using an electrospinning method, which allows the chemical adsorption of polysulfides throughout a robust conductive film. A significant enhancement in cycle stability and rate capability was achieved by incorporating this interlayer with a composite cathode of S/MWCNT. These results herald a new approach to building functional interlayers by integrating metal oxides with conductive frameworks. The derivatives of the TiO2/C interlayer was synthesized by changing the precursor concentration and carbonization temperature. Finally, a dual-interlayer was fabricated by simply coating titanium nitride (TiN) nanoparticles onto an electro-spun carbon nanofiber mat, which was then sandwiched with a sulfur/assembled Ketjen Black (KB) composite cathode with an ultra-high sulfur loading. The conductive polar TiN nanoparticles not only have a strong chemical affinity to polysulfides through a specific sulfur-nitrogen bond but also improve the reaction kinetics of the cell by catalyzing the conversion of the long-chain polysulfides to lithium sulfide. Besides, carbon nanofiber mat ensures mechanical robustness to TiN layer and acts as a physical barrier to block polysulfides diffusion. The incorporation of dual interlayers with sulfur cathodes offers a commercially feasible approach to improving the performance of Li-S batteries.
dc.description.sponsorshipKrishnan-Ang Studentship
dc.language.isoen
dc.rightsAll rights reserved
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectLithium-sulfur Batteries
dc.subjectInterlayers
dc.subjectNanostructure
dc.subjectPolysulfides
dc.subjectChemical interaction
dc.subjectMetal oxides
dc.subjectMetal nitrides
dc.subjectElectrospinning
dc.subjectCarbon nanofibers
dc.titleDevelopment of New Cathodic Interlayers with Nano-Architectures for Lithium-Sulfur Batteries
dc.typeThesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridge
dc.publisher.departmentDepartment of Materials Science and Metallurgy
dc.date.updated2018-05-10T05:11:58Z
dc.identifier.doi10.17863/CAM.22944
dc.contributor.orcidZhao, Teng [0000-0002-2398-2495]
dc.publisher.collegeTrinity College
dc.type.qualificationtitlePhD in Materials Science
cam.supervisorKumar, R. Vasant
cam.thesis.fundingfalse
rioxxterms.freetoread.startdate2019-05-10


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