Reinold, Lukas Mirko (2016)
SiCN based Anode Materials for Lithium-Ion Batteries.
Technische Universität Darmstadt
Dissertation, Erstveröffentlichung
Kurzbeschreibung (Abstract)
This thesis deals with the investigation of polymer-derived silicon carbonitride based anode materials for their application in lithium-ion batteries. Carbon-rich silicon carbonitrides are obtained by a pyrolysis of different organosilicon precursors, namely poly(phenylvinylsilylcarbodiimide), poly(phenylvinylsilazane), poly(diphenylsilylcarbodiimide), poly(phenylsilsesquicarbodiimide) and poly(phenylsilsesquiazane). The materials are characterized by means of Raman spectroscopy, elemental analysis, X-ray diffraction and Galvanostatic Cycling with Potential Limitation. Promising results with respect to the capacity, rate capability and cycling stability have been obtained. Namely, silicon carbonitride derived from poly(phenylvinylsilazane) exhibits a 1st cycle specific delithiation capacity as high as 725 mAh/g and a specific capacity of 624 mAh/g after prolonged cycling.
Extensive studies on the influence of the pyrolysis temperature between 800 °C and 1300 °C on the electrochemical behavior have been performed on the active materials derived from poly(phenylvinylsilylcarbodiimide) and poly(phenylvinylsilazane). It has been found that the pyrolysis temperature influences the hysteresis, the specific capacity, the rate capability and several aspects related to the stability of the prepared electrodes. Single Particle Measurements have been conducted, giving insight into the intrinsic properties of the materials, namely the charge transfer resistance and the minimum diffusion coefficient. These values are found to depend on the pyrolysis temperature, too. Solid state 29Si, 13C and 7Li Nuclear Magnetic Resonance measurements on poly(phenylvinylsilylcarbodiimide) and poly(phenylvinylsilazane) pyrolyzed at 1100 °C reveal that the free carbon phase acts as major storing site for the lithium ions and that lithium ion motion takes place via a continuum diffusion mechanism described by an activation law.
Moreover, the prospects of silicon carbonitride as stabilizing matrix for prolonged electrochemical cycling of silicon nano powders are addressed. A variety of composites have been prepared differing in the organosilicon precursor, the ratios of compounds, presence/absence of conductive coatings and geometric structure. The highest cycling stability has been achieved for silicon nano particles located in a porous ceramic matrix.
Typ des Eintrags: | Dissertation | ||||
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Erschienen: | 2016 | ||||
Autor(en): | Reinold, Lukas Mirko | ||||
Art des Eintrags: | Erstveröffentlichung | ||||
Titel: | SiCN based Anode Materials for Lithium-Ion Batteries | ||||
Sprache: | Englisch | ||||
Referenten: | Riedel, Prof. Dr. Ralf ; Roth, Prof. Dr. Christina | ||||
Publikationsjahr: | 2016 | ||||
Ort: | Darmstadt | ||||
Datum der mündlichen Prüfung: | 23 Dezember 2015 | ||||
URL / URN: | http://tuprints.ulb.tu-darmstadt.de/5428 | ||||
Kurzbeschreibung (Abstract): | This thesis deals with the investigation of polymer-derived silicon carbonitride based anode materials for their application in lithium-ion batteries. Carbon-rich silicon carbonitrides are obtained by a pyrolysis of different organosilicon precursors, namely poly(phenylvinylsilylcarbodiimide), poly(phenylvinylsilazane), poly(diphenylsilylcarbodiimide), poly(phenylsilsesquicarbodiimide) and poly(phenylsilsesquiazane). The materials are characterized by means of Raman spectroscopy, elemental analysis, X-ray diffraction and Galvanostatic Cycling with Potential Limitation. Promising results with respect to the capacity, rate capability and cycling stability have been obtained. Namely, silicon carbonitride derived from poly(phenylvinylsilazane) exhibits a 1st cycle specific delithiation capacity as high as 725 mAh/g and a specific capacity of 624 mAh/g after prolonged cycling. Extensive studies on the influence of the pyrolysis temperature between 800 °C and 1300 °C on the electrochemical behavior have been performed on the active materials derived from poly(phenylvinylsilylcarbodiimide) and poly(phenylvinylsilazane). It has been found that the pyrolysis temperature influences the hysteresis, the specific capacity, the rate capability and several aspects related to the stability of the prepared electrodes. Single Particle Measurements have been conducted, giving insight into the intrinsic properties of the materials, namely the charge transfer resistance and the minimum diffusion coefficient. These values are found to depend on the pyrolysis temperature, too. Solid state 29Si, 13C and 7Li Nuclear Magnetic Resonance measurements on poly(phenylvinylsilylcarbodiimide) and poly(phenylvinylsilazane) pyrolyzed at 1100 °C reveal that the free carbon phase acts as major storing site for the lithium ions and that lithium ion motion takes place via a continuum diffusion mechanism described by an activation law. Moreover, the prospects of silicon carbonitride as stabilizing matrix for prolonged electrochemical cycling of silicon nano powders are addressed. A variety of composites have been prepared differing in the organosilicon precursor, the ratios of compounds, presence/absence of conductive coatings and geometric structure. The highest cycling stability has been achieved for silicon nano particles located in a porous ceramic matrix. |
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URN: | urn:nbn:de:tuda-tuprints-54285 | ||||
Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 500 Naturwissenschaften 500 Naturwissenschaften und Mathematik > 530 Physik 500 Naturwissenschaften und Mathematik > 540 Chemie 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften und Maschinenbau |
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Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Disperse Feststoffe |
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Hinterlegungsdatum: | 05 Jun 2016 19:55 | ||||
Letzte Änderung: | 05 Jun 2016 19:55 | ||||
PPN: | |||||
Referenten: | Riedel, Prof. Dr. Ralf ; Roth, Prof. Dr. Christina | ||||
Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 23 Dezember 2015 | ||||
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