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Materials and Components for Lithium-Ion Power Sources
Jirák, Tibor ; Kadlec, Jaromír (referee) ; Paidar,, Martin (referee) ; Vondrák, Jiří (advisor)
The dissertation thesis deals with electrode materials and components for lithium-ion power sources. The thesis works with two different kinds of materials, concretely nanostructured Li4Ti5O12 with spinel basis and LiCoO2 with layered structure. The electrochemical properties, structure and element analysis and utilization possibilities in electrochemical industry of new technological electrode material Li4Ti5O12 were investigated. The influences of admixtures and electrolytes on characteristics of electrode materials with aforesaid active masses were also examined. Low cost price, environmental safety and obtained results of electrochemical measurements and structure analysis refer to wide possibilities of usage electrode material Li4Ti5O12 in the field of electrochemistry.
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Electrode Active Materials for Lithium-Ion Accumulators
Čech, Ondřej ; Oriňáková, Renáta (referee) ; Paidar,, Martin (referee) ; Sedlaříková, Marie (advisor)
This doctoral thesis deals with synthesis and characterisation of electroactive electrode materials for li-ion batteries and accumulators. The work is divided into two main parts. One deals with LiFePO4 based cathode composite electroactive material and in the second is described the synthesis and utilization of monoclinic TiO2(B) as an anode for li-ion cell. The main aim of the work is to relate the synthesis procedure and structural properties of both materials to its electrochemical preformance.
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Materials for Supercapacitors
Dvořák, Petr ; Paidar,, Martin (referee) ; Trnková, Libuše (referee) ; Sedlaříková, Marie (advisor)
This dissertation deals with the electrode materials, liquid and gel electrolytes suitable for supercapacitors. In the field of electrode materials were investigated carbon materials based on carbon blacks, expanded and micronized graphite suitable for supercapacitors working on the principle electrochemical double layer. Another area which this thesis deals with are aprotic liquid electrolytes prepared from suitable types of salts and aprotic solvents. The last part is focused on the preparation and subsequent electrochemical characterization of gel polymer electrolytes in order to increase the ionic conductivity of these electrolytes.
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Liquid Electrolytes for Lithium-Ion Batteries with Enhance Fire Safety
Máca, Josef ; Paidar,, Martin (referee) ; Studničková, Marie (referee) ; Sedlaříková, Marie (advisor)
Dissertation thesis is focused on study of liquid electrolytes for lithium ion batteries. The electrical and physical properties of aprotic electrolytes are observed. The main goal is to increase the fire safety of the batteries. An anhydrous solvents and there blends was investigated. The common used solvents mixtures and new low flammable solvents were used. The common used solvents were used propylene carbonate, ethylene carbonate and others. The new solvents were sulfolane and dimethyl sulfone. In the second part of the work the phosphor base flame retardants as additive in electrolytes was investigated. The last part deals with ionic liquids and there possible use as electrolyte in lithium ion batteries.
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Nonequilibrium Brownian dynamics in periodic energy landscapes
Paidar, Jaroslav ; Ryabov, Artem (advisor) ; Žonda, Martin (referee)
The collective dynamics of Brownian particles in porous structures is an important topic for both theory and experiment. A good understanding of Brownian dynamics of interacting particles moving in one dimension has recently been achieved in several models. The theoretical description of these models focuses on infinitely large systems, although real systems are in usually small. This thesis studies the effect of the size of a system of interacting particles driven by a force on their transport behavior in a periodic potential. We have used simulations of a single-particle model with analytically solvable results as reference data. For this model, simulations were performed using the Euler- Maruyama method. Multi-particle simulations were performed for two different types of particle interactions. The rigid-ball type interaction served as the basis for the analysis of behavior of a smoothed-barrier type interaction potential case that allowed for the particles to pass through each other. The particle velocity and diffusion coefficient were studied as a function of various system parameters such as particle softness, size, and density or system size. 1
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Pt-based bimetallic catalysts for polymer membrane fuel cells prepared by magnetron sputtering
Orság, Martin ; Khalakhan, Ivan (advisor) ; Paidar, Martin (referee)
The use of fossil fuels has started a climate change connected to risks such as extreme heatwaves, rising sea level, extinction of species and other catastrophes. That's why it's necessary to move to carbon neutral economics. Hydrogen fueled proton exchange membrane fuel cells (PEMFCs) can power vehicles without emitting dangerous emissions. The main obstacle to their widespread use resides on its cathode side where a sluggish oxygen reduction reaction takes place. Because of that, PEMFC cathodes require large amount of expensive platinum catalyst which moreover operates under aggressive corrosive environment. This thesis explores the possibilities of replacing platinum with a bimetallic alloy of platinum and a cheaper metal. Pt-Co, Pt-Cu and Pt-Y bimetallic catalysts of different compositions (Pt75M25, Pt50M50 and Pt25M75) were prepared by magnetron sputtering. The catalysts were thoroughly characterized and their activity and stability were tested. The results show that replacing platinum with a bimetallic alloy can significantly increase the specific power activity of the cathode catalyst in PEMFC. On the other hand, bimetallic catalysts, especially those with lower amount of Pt, are more prone to degradation. Nevertheless, bimetallic catalysts with Pt75M25 composition showed a promising...
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Gel Polymer Electrolytes for Electrochemical Power Sources
Jahn, Michal ; Bartušek, Karel (referee) ; Paidar,, Martin (referee) ; Sedlaříková, Marie (advisor)
Dissertation thesis is focused on study of gel polymer electrolytes for electrochemical power sources, but also for other application. The electrical, electrochemical, mechanical and optical properties of gel electrolyte samples were measured in this work. The main goal was to prepare samples with high specific conductivity and with largest possible potential windows. Thermal stability of some samples was also monitored using thermogravimetric analyzes. The optimization of the chemical composition, quantities and ratios of individual chemicals has been made. Comparison of thermal polymerization and UV polymerization was performed. In the first part of the work, aprotic solvents and their mixtures in combination with lithium and sodium salts and one ammonium salt were investigated. Another subject of research was various crosslinking agents with methacrylate-based monomers. The second part of the work investigated the effect of ionic liquids, phosphor base flame retardants and nanoparticles as additives to gel electrolytes. In the last part of the work, the influence of the magnetic and electric field on the polymerization of gel electrolytes containing nanoparticles and selected copolymers was studied. Finally, a Li-ion cell with a graphite anode, LiFePO4 cathode and selected gel electrolyte was assembled.
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Liquid Electrolytes for Lithium-Ion Batteries with Enhance Fire Safety
Máca, Josef ; Paidar,, Martin (referee) ; Studničková, Marie (referee) ; Sedlaříková, Marie (advisor)
Dissertation thesis is focused on study of liquid electrolytes for lithium ion batteries. The electrical and physical properties of aprotic electrolytes are observed. The main goal is to increase the fire safety of the batteries. An anhydrous solvents and there blends was investigated. The common used solvents mixtures and new low flammable solvents were used. The common used solvents were used propylene carbonate, ethylene carbonate and others. The new solvents were sulfolane and dimethyl sulfone. In the second part of the work the phosphor base flame retardants as additive in electrolytes was investigated. The last part deals with ionic liquids and there possible use as electrolyte in lithium ion batteries.
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Electrode Active Materials for Lithium-Ion Accumulators
Čech, Ondřej ; Oriňáková, Renáta (referee) ; Paidar,, Martin (referee) ; Sedlaříková, Marie (advisor)
This doctoral thesis deals with synthesis and characterisation of electroactive electrode materials for li-ion batteries and accumulators. The work is divided into two main parts. One deals with LiFePO4 based cathode composite electroactive material and in the second is described the synthesis and utilization of monoclinic TiO2(B) as an anode for li-ion cell. The main aim of the work is to relate the synthesis procedure and structural properties of both materials to its electrochemical preformance.
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Materials for Supercapacitors
Dvořák, Petr ; Paidar,, Martin (referee) ; Trnková, Libuše (referee) ; Sedlaříková, Marie (advisor)
This dissertation deals with the electrode materials, liquid and gel electrolytes suitable for supercapacitors. In the field of electrode materials were investigated carbon materials based on carbon blacks, expanded and micronized graphite suitable for supercapacitors working on the principle electrochemical double layer. Another area which this thesis deals with are aprotic liquid electrolytes prepared from suitable types of salts and aprotic solvents. The last part is focused on the preparation and subsequent electrochemical characterization of gel polymer electrolytes in order to increase the ionic conductivity of these electrolytes.
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