Title:	Organometallic Polymer - Graphene Nanocomposites: Promising Battery Materials
Authors:	Beladi Mousavi, Seyyed Mohsen
Thesis advisor:	Prof. Dr. Lorenz Walder
Thesis referee:	Prof. Dr. Martin Steinhart
Abstract:	Preparation, structural analysis, and electrochemical performance of a new cathodic battery material, consisting of a nanocomposite of poly(vinylferrocene) (PVFc) (Eox: 0.4 V vs. Ag/AgCl) and reduced graphene oxide (rGO), are described. The nanocomposite shows the highest charge-discharge efficiency (at a rate of 100 A g-1) ever reported for any organic / organomatellic battery material. Remarkably, the composite is “thickness scalable” up to 0.21 mAh cm-2 (770 mC cm−2 at 29 μm film thickness) on a flat surface with > 99% coloumbic efficiency, exhibiting a specific capacity density of 114 mAh g−1. The composite material is binder free and the charge storing material (PVFc) accounts for > 88% of the total weight of the cathodic material. The secret behind such a performance is the electrostatic interaction between the redox polymer in its oxidized state (exhibiting positive charge) and the original filler i.e., graphene oxide (GO) with negative surface charge. This self-assembling step is analyzed by zeta potential measurements, and a modeling study confirms the experimentally found heavy polymer loading on the GO (in aqueous solution). The efficient self-assembly led to composites with high ratio of redox polymer / GO where all polymers are in close contact with GO sheets. The stable colloidal solution was casted on the surface of a flat current collector and the insulating GO was electrochemically transformed to conductive reduced graphene oxide (rGO). The GO / rGO transformation was catalyzed by methyl viologen dichloride (MV++) working as a redox shuttle (solublized in the aqueous electrolyte) and thereby accelerating the electron transfer to GO. Complete GO / rGO transformation and the quantitative ion breathing of the composite are found by means of electrochemical quartz crystal microbalance and electrochemical AFM.
URL:	https://osnadocs.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2017012715280
Subject Keywords:	metallocene battery; composite
Issue Date:	27-Jan-2017
License name:	Namensnennung 3.0 Unported
License url:	http://creativecommons.org/licenses/by/3.0/
Type of publication:	Dissertation oder Habilitation [doctoralThesis]
Appears in Collections:	FB05 - E-Dissertationen

This item is licensed under a Creative Commons License