Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Subject: search.filters.subject.BatteriesWoS Q: search.filters.wosQuartile.N/A

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Now showing 1 - 6 of 6
  • Master Thesis
    Modeling and Thermo-Economic Analysis of a Photovoltaic-Battery Hybrid Energy System: a Case Study in Yenikale Geothermal Heat Center
    (01. Izmir Institute of Technology, 2023) Uslu, Gökçe; Gökçen Akkurt, Gülden; Helvacı, Hüseyin Utku
    Water is vital for agriculture accounting 50-70% of the total global use of fresh water for irrigation. Geothermal water as a renewable energy source is used to generate electricity, heat and cool. The remaining water can be desalinated to be used for agricultural irrigation. Energy demand of desalination systems is high and mostly rely on fossil fuels increasing cost and greenhouse gas emissions. Thus, renewable energy use in desalination process is increasing. Based on a research project, a pilot desalination system is installed in Yenikale Heat Center of Balcova-Narlidere Geothermal District Heating System to desalinate geothermal water and use for agricultural irrigation. The desalination system is powered by a solar PV system which meets energy need entirely in summer but only 30-50% in winter. The remaining energy need is supplied from the grid. The aim of this study is to maximize the utilization of solar energy for the desalination process while minimizing reliance on the grid. To achieve this objective, three different scenarios are analyzed based on three different solar radiation values of 2021 integrating a battery system. For each scenario; first, battery capacities and the number of PV panels are determined. Then, energy, exergy and exergo-economic analysis are conducted. The parameters calculated in economic analysis are net present value, payback period and cost of energy production. One of the main results obtained is the unit energy cost for solar driven desalination system 0.28 $/kWh which is in a good agreement with the literature (0.214-0.23 $/kWh).
  • Master Thesis
    Synthesis of Indandione-Based Porous Organic Polymers and Their Applications in Zinc-Ion Batteries
    (01. Izmir Institute of Technology, 2022) Şimşek, Gizem; Büyükçakır, Onur
    There has been growing interest in porous organic polymers (POPs) in recent years due to their large surface area, easy chemical tunability, sustainability, and high thermal and chemical stability. Due to their exceptional properties, they are suitable for use as platforms in various applications, including gas storage, separation, catalysis, and, more recently, energy storage systems. In this regard, it is imperative to design new functional POPs with a large surface area, permanent porosity, and physicochemical stability. In this thesis, we have presented indandione-based POPs (r-POPs) prepared by an acid-catalyzed condensation reaction between s-indacene-1,3,5,7(2H,6H)-tetraone and benzene-1,3,5-tricarboxaldehyde under highly environmentally friendly conditions. In order to optimize the reaction conditions, we first synthesized the model compound, namely 2-benzylidene-1H-indene-1,3(2H)-dione. The model compound was characterized by using 1H and 13C-NMR spectroscopy. Using different types of acids, we have investigated the effect of acid on polymerization and its textural properties. The polymers were characterized using various characterization techniques. Due to increased interest in renewable energy as a fossil fuel substitute, energy storage systems have attracted colossal interest, and rechargeable aqueous zinc-ion batteries (ZIBs) are seen as promising energy storage systems, particularly for grid-scale applications. In this respect, the carbonyl-rich structure of r-POPs transforms them into a potential electrode material. Thus, we have also investigated their electrochemical performances as cathode materials for ZIBs. Although r-POPs showed low electrochemical performance in capacity and cycle life, they have great potential to be an electrode material in other metal-ion batteries.
  • Master Thesis
    Synthesis and Characterization of High Nickel Content Cathode Materials for High Performance and Capacity Reach in Li-Ion Batteries
    (Izmir Institute of Technology, 2022) Uğur, Turgut; Karabudak, Engin
    Due to their high energy density, low self-discharge properties, nearly negligible memory effect, high open-circuit voltage, and extended service life, lithium-ion batteries continue to gain interest as a promising energy storage technology. In the automotive industry, high-energy lithium-ion batteries have become the preferred power source for electric vehicles and hybrid electric vehicles in recent years. With the development of lithium-ion battery technology, several materials have been used into the cathodes and anodes in order to improve performance. LiNiCoAlO4, LiMn2O4, LiNiMnCoO4, Li4Ti5O12 and LiFePO4are five lithium-ion batteries that are commonly utilized in commercial EVs today. NMC cathode material is one of the most effective lithium-ion battery materials for balancing specific qualities. The battery cathode of NMC is strengthened with a specific ratio of three synthetic components (Nickel, Manganese and Cobalt). Depending on the proportions of these three chemical constituents, battery performance can vary. Synthesis, characterisation, and electrochemical studies of cathode materials with a high Nickel content were performed in this project in an effort to boost the specific capacity and durability of Li-ion batteries. In these preliminary studies, the synthesis and characterization of Ni(OH)2 structures, which serve as a starting material for the synthesis of cathode materials with a high Nickel content, was also a goal. In the research, the spherical Ni(OH)2 structure was effectively synthesized, and excellent electrochemical results were achieved. SEM and XRD analyses were performed on the resulting products.
  • Master Thesis
    Synthesis and Characterization of Aluminum Doped To Extend Cathode Life in Li-Ion Batteries
    (01. Izmir Institute of Technology, 2021) Tekin, Onur; Karabudak, Engin
    Lithium-ion batteries have an important place in meeting the energy needs and are of greater importance than their cognates, thanks to their characteristics as secondary batteries. Volumetric and gravimetric energy densities are the main features that carry lithium-ion batteries to the top. Lithium-ion batteries consist of different parts: cathode, anode, separator and electrolyte. While the anode materials are generally based on silicon, carbon and tin, the cathode materials include layered LiCoO2, spinel LiMn2O4, olivine LiFePO4, layered LiNi0,8Co0,15Al0,05O2(NCA) and layered LiNiCoMnO2 (NMC). Nmc and nca cathode materials stand out due to their high energy densities. Of course, lithium-ion batteries also have some disadvantages. A prime example of this is the capacity reductions it experiences with the increasing number of cycles. The main reasons for the decrease in capacity are; The transformation of the layered structure into spinel structure, the contamination of the Lio structure on the cathode to the electrolyte structure as a result of the side reactions that occur, damage the stable structure of the electrolyte and lead to Li loss. Metal oxide surface modification methods come to the fore in studies conducted to prevent these disadvantages. In this study, nmc structure was synthesized by reprecipitation method. Xrd, and sem analyzes of the obtained structure were taken. Al2O3 surface modification method was applied on the cathode surface. Cyclic voltammetry analyzes of the nmc structures with and without the modification applied were made with the help of potentiometry and the results were compared.
  • Master Thesis
    Effects of Grid Design on Lead-Acid Battery Performance
    (Izmir Institute of Technology, 2017) İşler, Tuğçe; Ebil, Özgenç; Top, Ayben
    In today’s world, approximately 88 percent of the total energy demand is supplied by fossil fuels; however, it has become clear that; other energy sources are needed due to limited fossil fuels. The demand for energy can most effectively be filled by renewable energy sources as installed energy storage capacity is growing rapidly. If renewable energy sources advance enough to fulfill the high demand, earth-friendly, clean and sustainable energy will help to protect the environment, thus ensuring a healthier life for future generations. Energy storage systems are essential in this endeavor, and in order to become more prevalent, storage systems for renewable energy sources must supply electricity without interruption as much as possible. As an electrochemical storage, a battery with a high level of performance, high energy density and life cycle could offer a viable solution for electricity storage provided that battery cost should be economically viable. This thesis aims to improve the geometry of the grid used in lead acid batteries in order to obtain a more uniform current and potential distribution, and minimize the potential drop for improved battery performance. A 3D mathematical model was developed using finite element method to evaluate the behavior of the grid under various conditions. Five different porous grid geometries were simulated under different loads and optimum grid geometry was identified. The 3D mathematical model of the lead-acid battery based on finite element method was simulated under certain conditions in order to evaluate the effect of grid geometry on battery performance.
  • Master Thesis
    Modelling and Simulation of Zinc Based Batteries
    (Izmir Institute of Technology, 2016) Toptop, Evren; Ebil, Özgenç; Yüksel Özşen, Aslı
    Energy is the determining factor of productivity and quality of living. Electric energy is the most used energy form and lack of reserve for it hinders widespread use of renewable energy technologies. Advancements in renewable energy technologies, electric vehicles and consumer electronics are highly dependent on developments of new battery technologies. High energy density, long service life, using benign and abundant materials are few of the key requirements for next generation batteries. A model, a mathematical description of the system, is an effective tool to predict the behavior of batteries under specific conditions, thus reducing cost and time for the development. A mathematical model using finite element method was designed to simulate the discharge behavior of an experimental nickel-zinc battery that includes composite zinc and commercial nickel electrodes. The model employs thermodynamic and kinetic expressions for porous electrodes considering the concentration dependency of battery characteristics. The effects of initial zinc and nickel concentrations, anodic transfer coefficients of zinc and nickel electrode reactions on the electrochemical performance of the battery have been simulated. The discharge voltage, electrode porosities, and species concentrations in electrodes as a function of model parameters and time have been evaluated. It is observed that the model results are consistent with the experiment results considering that the battery operation is limited with zinc concentration. Initial zinc concentration is the major determining factor on discharge duration. Nickel oxyhydroxide concentration affects voltage magnitude. Transfer coefficients have only limited effects on discharge voltage and concentrations.