• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 33
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 41
  • 24
  • 14
  • 12
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Akumulace elektrické energie pro zdroj s nestabilní produkcí / Accumulation of electricity for a source with unstable production

Petrenec, Jan January 2020 (has links)
This diploma thesis deals with possibilities of accumulation of electricity generated by renewable sources with unstable production. Several goals were set by an assignment of this thesis. Within a research, current trends of the accumulation are presented in detail on examples of specific representatives with their technical parameters and economic possibilities. Further, an unstable source of electricity – the wind farm of three power plants Multibrid 5000 with all its parameters and operational details is defined for purposes of individual designs of accumulation systems. Firstly, the detailed design of an advanced compressed air energy storage (A-CAES) is realized. It includes a thermodynamic calculation of chosen components, their partial technical solutions, a financial evaluation of investment and a determination of theoretical payback period. Furthermore, the design for accumulators Tesla Powerpack is realized. It contains a calculation of individual system parameters, a financial evaluation of investment and a determination of theoretical payback period. Last part of the thesis is dedicated to a comparison and an evaluation of the achieved results of both realized methods of the electricity accumulation. In the end, A-CAES is chosen as more perspective variation.
22

Deponované vrstvy na bázi olova a kobaltu pro Li-ion akumulátory / Deposited layers based on lead and cobalt for Li-ion batteries

Dorotík, David January 2021 (has links)
The diploma thesis deals with the principles of operation of lithium ion batteries and their properties when using deposited thin films. The thesis is mainly focused on the formation of thin films using the electrolytic method and subsequently testing the properties of the thin film in an electrochemical cell. The test criteria are mainly the value of the capacity of the prepared electrode and the impact of cycling on the electrode layer itself, where the deposited layer is assessed before cycling and after cycling on an SEM microscope..
23

Zlepšování užitných vlastností olověného akumulátoru / Improving of use properties of lead-acid accumulator

Szabó, Jaroslav January 2011 (has links)
Lead-acid accumulators are the oldest and most common type of secondary cells. There are still some problems to solve. Grid corrosion in sulphuric acid is one of them, which reduced lifetime of lead-acid accumulators. The first part of work is focusing on a general theoretic description of lead – acid accumulators. Following is a description of the workstation and method of measuring. The final part of the text is measuring on an experimental cell.
24

Akumulace elektrické energie z obnovitelných zdrojů / Accumulation of electricity from renewable sources

Dědek, Dušan January 2008 (has links)
This work is specialized on problems accumulation electricity power from renewable sources and production electricity power from renewable sources for select object. First part describes renewable sources and their use in our conditions. Second part is specialized on accumulators specific for renewable sources. Third part compare to production electricity power from photovoltaic power station and windy power station and their combination for select object. Further accumulation these select sources. Final fourth part describe about their comparison from position how of technical so economic.
25

Akumulace elektrické energie z obnovitelných zdrojů / Accumulation of electricity from renewable sources

Špičák, Ladislav January 2009 (has links)
This diploma thesis is specialized on problems of electrical energy accumulation from renewable resources. This renewable resources used in Czech Republic are described in the first part. Next, in the second chapter is identification with principles of electrical energy accumulation. In the third part, there is a proposal of electrical energy accumulation system which makes a supply of electrical energy from photovoltaic system by the help of accumulation system in compressed air equally. In the final part, there is a total analysis of technical economic aspect for proposed system.
26

Akumulace energie z obnovitelných zdrojů energie / Power-accumulation from renewable energy sources

Kratochvíl, Tomáš January 2010 (has links)
The diploma thesis is focused on problem of accumulating electric energy from renewable resources. The first section describes renewable energy sources, which are possible to use in the Czech Republic and principles of accumulating electric energy. In the following section are suggested systems of accumulating energy to accumulators by compressed air and pumped storage power station. These systems are proposed for uniform power supply from photovoltaic power station to electric power network all day. In conclusion, the suggested systems are compared from economic-technical perspective.
27

Studium hydroxidů a oxidů kovů ve vodných roztocích / Study of Metal Oxides and Hydroxides in Aqueous Solutions

Špičák, Petr January 2011 (has links)
This dissertation work deals with analysis of nickel hydroxide phases, their oxidation compounds, their stability and degradation mechanisms of electrochemically more active alpha phase on standard beta phase. The active material was prepared by both methods, electrodeposition and chemical precipitation. Main analysis method was Electrochemical Quartz Crystal Microbalance in combination with common analytical methods (cyclic voltammetry, potenciometry) can resolute between alpha and beta phases and quantitatively describe differences in main reaction by monitoring mass changes in the active material. Poor stability of the ?-Ni(OH)2 were improved by adding cations with valence two three and four into the structure instead of Ni atoms. The most important role plays cobalt and its hydroxide. Totally new way is to use titanium in combination with other cations. In electrolyte the most significant addition is LiOH, which has beneficial influent on cycle ability, stability in strong alkaline medium and cycle life.
28

Materiály a komponenty pro lithno-iontové zdroje proudu / Materials and Components for Lithium-Ion Power Sources

Jirák, Tibor January 2011 (has links)
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.
29

Záporná elektroda pro lithno-iontové akumulátory / Negative Electrode for Lithium-Ion Batteries

Libich, Jiří January 2015 (has links)
The dissertation thesis deals with investigation of electrode materials for Lithium-ion batteries. The main aim of investigation was focused to materials for negative electrode of Litihum-ion batteries. These negative electrode materials operate on intercalation principle. Object of interest are carbonaceous materials, especially their graphite forms. Graphite plays host role in lithium ion – graphite interactions that provides LiC6 compound. As a result of that investigation can be considered improving of graphite materials from stability, irreversible capacity and other parameters points of view. This kind of investigation takes an important part in field of elementary investigation work engaged to the next generation of Lithium-ion batteries. The work also describes the fire safety issue of Lithium-ion batteries along with compatibility of negative electrode materials and aprotic electrolytes.
30

Vliv iontových kapalin na funkční části lithium - iontových akumulátorů / The influence of ionic liquids on functional elements in lithium-ion batteries

Meščánková, Veronika January 2016 (has links)
This thesis deals with ionic liquids, their conductivity and the action of the electrode materials, separators and current collectors. The theoretical part is focused on the properties of ionic liquids, Li-ion batteries, corrosion, conductivity and analysis elements. The practical part is focused on the production of graphite electrodes, measuring the conductivity of ionic liquids with different parts of lithium – ion battery and measuring the potential window. Also, there is the effect of ionic liquids described in these parts.

Page generated in 0.0435 seconds