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AuthorSchwarz, Rainerdc.contributor.author
Date of accession2018-02-06T09:58:58Zdc.date.accessioned
Available in OPARU since2018-02-06T09:58:58Zdc.date.available
Year of creation2017dc.date.created
Date of first publication2018-02-06dc.date.issued
AbstractTechnological evolution puts up an ever-growing demand on energy storage – challenging today’s technology. Magnesium batteries are a prime candidate to those future demands – theoretically energy dense, 2205 mAh.g-1, abundant and comparatively cheap. [1.4, 1.5] Despite promising properties, magnesium batteries still face major challenges until their commercialization. The favored, high energy density, magnesium metal anode is, at the current state of research, only compatible to a handful of electrolytes, e.g. based upon either magnesium-organo-halo-aluminates or magnesium-borohydrides. [1.9, 1.10] Electrolytes based upon conventional magnesium salts e.g. such as halides, perhalates or imides seem to be incompatible to the magnesium metal surface [1.6] where the electrolyte degenerates and forms a passivating, magnesium ion impermeable, surface layer. This work presents investigations on readily mixable salt / solvent electrolytes and beyond this, the investigations on a new bis(cyclopentadienyl) magnesium electrolyte. This new electrolyte is highly suitable for a metallic magnesium anode and is comprehensively investigated. The results of electrochemical performance testing show an excellent cycling stability for over 500 cycles with a coulombic efficiency of 98 %. SEM and XRD analysis show the deposition of metallic magnesium onto a copper substrate, as well as IR and NMR studies on the fresh and cycled / aged electrolyte show no indication of electrolyte degeneration. Furthermore a comprehensive evaluation of conversion type metal electrodes and carbonaceous electrodes is showcased. The electrodes are electrochemically characterized in different electrolytes. The conversion type metal electrodes exhibit low overpotentials and high current densities in a lithium environment benchmark and no electrochemical activity in a Mg(BH4)2 / tetra-glyme electrolyte. The cyclic voltammetry and constant current testing of the carbonaceous electrodes in different magnesium electrolytes for various carbon materials presents reversible intercalation of magnesium into graphite for the first time. The obtained coulombic efficiencies are poor and the capacity is limited to 10- 20 mAh.g-1. SEM and XRD investigations, prior and subsequently to the electrochemical testing, reveal almost full degradation of the conversion electrodes and only little for the carbonaceous electrodes.dc.description.abstract
Languageendc.language.iso
PublisherUniversität Ulmdc.publisher
LicenseStandarddc.rights
Link to license texthttps://oparu.uni-ulm.de/xmlui/license_v3dc.rights.uri
KeywordMagnesocenedc.subject
KeywordAnode materialdc.subject
Dewey Decimal GroupDDC 540 / Chemistry & allied sciencesdc.subject.ddc
LCSHElectrochemistrydc.subject.lcsh
LCSHEnergy storagedc.subject.lcsh
LCSHStorage batteriesdc.subject.lcsh
LCSHElectrolytesdc.subject.lcsh
TitleNew electrolytes and anode materials for magnesium batteriesdc.title
Resource typeDissertationdc.type
Date of acceptance2017-11-10dcterms.dateAccepted
RefereeTillmetz, Wernerdc.contributor.referee
RefereeFichtner, Maximiliandc.contributor.referee
DOIhttp://dx.doi.org/10.18725/OPARU-5422dc.identifier.doi
PPN1013674545dc.identifier.ppn
URNhttp://nbn-resolving.de/urn:nbn:de:bsz:289-oparu-5479-3dc.identifier.urn
GNDEnergiespeicherungdc.subject.gnd
GNDAkkumulatordc.subject.gnd
GNDMagnesiumdc.subject.gnd
GNDElektrolytdc.subject.gnd
FacultyFakultät für Naturwissenschaftenuulm.affiliationGeneral
Grantor of degreeFakultät für Naturwissenschaftenuulm.thesisGrantor
DCMI TypeTextuulm.typeDCMI
CategoryPublikationenuulm.category
In cooperation withZentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW)uulm.cooperation
Bibliographyuulmuulm.bibliographie


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