Πλοήγηση ανά Συγγραφέας "Nikolidakis-Owens, David"

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  • Μικρογραφία εικόνας
    Τεκμήριο
    Exploring composite metal oxide/carbon materials: growth mechanism and electrochemical performance for energy storage
    (ΕΛΜΕΠΑ, Σχολή Μηχανικών (ΣΜΗΧ), ΔΠΜΣ Νανοτεχνολογία για Ενεργειακές Εφαρμογές, 2025-07-15) Nikolidakis-Owens, David; Νικολιδάκης-΄Οουενς, Δαυίδ; Vernardou, Dimitra; Βερνάρδου, Δήμητρα
    In recent years, the growing global interest in environmental protection and climate change has increased the demand for efficient storage energy. Lithium-ion batteries, due to their high energy density, excellent cycle performance, small size and long lifetime performance, have gained a prominent position in everyday life, finding applications in portable devices (laptops, smart phones). However, to address safety concerns associated with the flammable organic solvents in conventional lithium-ion batteries, aqueous lithium-ion batteries have been developed. These water based systems offer enhanced safety and lower production costs, making them a promising alternative. Transition Metal Oxides, like nickel oxide (NiO), have emerged as promising anode materials for aqueous lithium-ion batteries due to their ability to reach high capacity values (700-1200 mAh/g), surpassing those of commercial graphite anode. However, their low electronic conductivity limits the rate performance. To overcome this limitation, the incorporation of conductive materials such as graphene and graphene oxide (GO) has been explored. These carbon-based materials improve the structural stability of the electrode and enhance reaction kinetics. Graphene oxide, in particular, has attracted growing interest due to its solubility in various solvents, dielectric properties and tunable electrical characteristics. By integrating GO, the resulting NiO/GO anode material can facilitate rapid electron transfer in aqueous lithium-ion batteries. In this study, GO was synthesized using a modified Hummers method, while NiO suspension and NiO/GO composite solution were both used as electrolytes in the electrodeposition process. The processing parameters like electrodeposition time, Li2SO4 electrolyte concentration, NiO concentration, PVP K12 and GO addition on the NiO suspension were systematically investigated. All samples were characterized through morphological, structural and electrochemical measurements by scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), X-ray diffraction spectroscopy (XRD) and cyclic voltammetry (CV). In conclusion, this dissertation highlights the potential of NiO and NiO/GO anode electrodes synthesized via the electrodeposition technique as cost-effective and promising films for anode materials in energy devices.