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Electrode Materials for Sodium-ion Batteries Based on Carbon
Homolka, Tomáš ; Binar, Tomáš (referee) ; Libich, Jiří (advisor)
This diploma thesis focuses on electrode materials for sodium batteries with a particular emphasis on anodes, especially hard carbon. The history of sodium-ion batteries and their operating principle are discussed as well. The project also describes the history of lithium ion batteries, as they share a significant part of their development and operating principle with sodium-ion batteries. In the practical part, measurements of rate capability, capacity and coulombic efficiency of the selected hard carbon are then performed. The sodation method is also tested and the effect of moisture on its properties is further investigated.
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Functional carbon layers on fiber structures
Opravil, Petr ; Čech, Ondřej (referee) ; Bača, Petr (advisor)
In this master‘s thesis, we will be informed about creation of carbon coatings on glass fibre structures. Described methods of carbon coating will be compared and we will chose appropriate method for available laboratory in constitution of electronic technologies. Thanks to it’s low price and simplicity, it was firstly chosen to test carbon deposition using dehydration of sugar using concentrated hydrochloric acid. Results of initial experiments helped to develop and propose new methods that were tested using multiple new microfiber samples. Results from these experiments helped choose a correct subtrate on which a function layer of carbon was deposited and later analyzed.
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Dissolved and gaseous nitrogen losses in forests controlled by soil nutrient stoichiometry
Oulehle, Filip ; Chuman, T. ; Hruška, Jakub ; Krám, Pavel ; Navrátil, Tomáš ; Tesař, Miroslav ; Ač, Alexander ; Urban, Otmar
This study investigates the consequences of chronic nitrogen deposition in forests, including its effects on soil and surface water quality, and greenhouse gas emissions. To predict these effects, the authors explore the controls over dissolved and gaseous nitrogen fluxes in temperate forests. Their findings indicate that stream leaching losses of dissolved nitrogen correspond with the nutrient stoichiometry\nof the forest floor, with stream N losses increasing as ecosystems progress towards phosphorus limitation. Soil nitrogen storage increases with oxalate extractable iron and aluminium content. The authors estimate soil gaseous losses based on 15 N stocks, which averaged 2.5±2.2 kg N ha-1 year-1 , comprising 20±14% of total nitrogen deposition. They also extrapolate the current gaseous nitrogen loss flux from forests globally to be 8.9 Tg N year-1 , which represents 39% of current nitrogen deposition to forests worldwide.
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Carbon materials for power sources
Tichý, Jiří ; Bača, Petr (referee) ; Novák, Vítězslav (advisor)
This work deals with carbon materials and using them in electrochemical energy sources. Object of this work was to prepare carbon materials and investigate their electrical properties. The theoretical part objects of the carbon materials, their properties, application in electrochemical energy sources and measurement methods used in experimental part. Experimental part describes the preparation of the electrodes with various carbon materials and summarizes the results of measurements.
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Desing of the carbon cap for the bike's fork
Gallo, Dominik ; Čípek, Pavel (referee) ; Košťál, David (advisor)
This bachelor's thesis discusses problems and solutions of design of the carbon crown for the bike's fork. It shows an overview of the possible implementation of the initial design up to final part. The output will be the crown made of carbon composite by mould pressing. For manufacturing the prototype form will be used 3D printing – Fused Deposition Modeling.
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Development of negative electrodes for lithium-ions batteries
Drahokoupil, Petr ; Libich, Jiří (referee) ; Sedlaříková, Marie (advisor)
This thesis deals with lithiation of negative electrode li-ion batteries. In this thesis is used several electrode materials: carbon, FeCl3, lithiated carbon electrodes and silicon carbide. Reduction of irreversible capacity lithium-ion batteries leads to increased capacity and also we can use new materials as a positive electrode. Thesis deals with the differences in the properties of materials using lithiation and their use in practice
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Pyrolytic graphite
Chýlková, Adéla ; Adam, Ondřej (referee) ; Němec, Karel (advisor)
The purpose of this bachelor thesis was to write a literature search summarizing knowledge about carbon-based materials and experimental determination of thermal expansion and thermal balance of samples of various types of graphite and evaluation of measured data. The research part of the work describes most of the currently known types of carbonaceous materials, with a more thorough study of pyrolytic graphite. The whole next chapter was devoted to a more thorough study of pyrolytic graphite. The second part of the thesis is focused on the experimental determination of thermal expansion and thermal balance on selected graphite samples (natural, expanded, pressed expanded and pyrolytic graphite). We used dilatometric analysis and thermogravimetry to solve this task. Finally, the measurement data were processed into graphs and relevant tables and conclusions were deduced.
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Natural Graphite as Negative Electrode Material for Lithium-Ion Batteries
Paulovics, Petr ; Jahn, Michal (referee) ; Libich, Jiří (advisor)
This bachelor thesis deals with an issue of lithium-ion batteries. It is focused on the negative (anode) electrode materials, dealing with the study of their electrochemical properties. The aim was to study the capacity characteristics of active electrode materials based on natural graphite. Mainly it was assessed the relationship morphology electrode material and the pressing pressure due to the electrochemical properties of the capacitive electrode. The first part of the thesis contains a theoretical introduction to the negative electrode materials with focuses on the composition and overall analysis of the lithium-ion cell. The second part is focuses on the manufacture, assembly and measurement of lithium-ion cells.
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