National Repository of Grey Literature 21 records found  beginprevious12 - 21  jump to record: Search took 0.01 seconds. 
Rotating disk electrode for measuring electrocatalyst materials
Vondrák, Jiří ; Sedlaříková, M. ; Coural, D.
In this work we investigated the oxygen reduction on various catalytic materials by means of the rotating disc electrode (RDE). Potentiostat AUTOLAB and the RDE Orion were used for this work. Electrodes made of Pt, Au, Ag and GC (glassy carbon) served or testing electrocatalytic materials in 2M KOH. Rotation speed varied from 3000 to 600 rpm with in lineraly distributed nine steps.
Basic properties of electrochemical supercapacitors
Vondrák, Jiří ; Sedlaříková, M. ; Novák, V. ; Nečesal, P. ; Černý, R.
The fundamental properties of two kinds of supercapacitors was investigated. Two different samples were obtained. One is capacitor STAR of nominal value 7 F and the other ULTRA was nominal capacity 100 F. Linear voltammetry, self-discharge curves, and indepedance spectroscopy was used for monitoring their properties.
Lithium ion batteries
Sedlaříková, M. ; Vondrák, Jiří ; Nečesal, P. ; Rozsívalová, Z.
Lithium ion batteries are the most promising accumulators from the viewpoint of specific energy. Their both electrodes are of intercalation type. Thus, their charge-discharge process is not accompanied by any change of electrolyte. Graphite is used as the material of negative electrodes while the positive electrodes are made from transition metal oxides such as manganese MnO2-x.
Electrochemical properties of PMMA-PC gels containing cadmium salts
Vondrák, Jiří ; Reiter, Jakub ; Sedlaříková, M. ; Bartušek, Karel ; Novák, V. ; Nováček, X.
We have described the preparation and properties of PMMA-PC gel polymer electrolytes containing lithium salts, tetraethylamonium salts and salts of Na, Mg, and Zn.
Voltammetric measurement of the Pt electrode capacity and the determination of the polyvalent ions diffusion coefficients in the glass melt
Rohanová, D. ; Vondrák, Jiří
The temperature dependence of diffusion coefficients of the polyvalent ions (iron and chromium)is one of characteristic structure parameters in given glass melt. The new voltammetry arrangement with triangular shape of the potential and the three-elec
Thermodynamics and digital simulation of intercalation processes
Vondrák, Jiří ; Reiter, Jakub ; Sedlaříková, M. ; Novák, V.
The thermodynamic theory of reversible electrochemical intercalation reactions is based on the consideration of interaction energy between two neighbouring sites.
Comparison of various oxides as cathode materials for Lithium batteries
Vondrák, Jiří ; Velická, Jana
The MnO2 prepared by our previously described procedurewas compared to commercial samples of MnO2 (Knappsack)and LiCoO2 (Cyprus Foote Chemicals). Our material offeredbetter peak powe load and lower energy density andreversibility.
Seven-segment display unit
Vondrák, Jiří ; Velická, Jana ; Klápště, Břetislav ; Reiter, Jakub
The development of a seven segment numerical display unitusing WO3 and V2O5 electrodes on I.T:O: glasses, and gel polymerelectrolyte is described.
Gel Polymer Electrolytes Based on PMMA
Vondrák, Jiří ; Klápště, Břetislav ; Velická, Jana ; Reiter, Jakub
Polymer gel electrolytes based on polymethylmethacrylateand aprotic solutions of metallic salts were prepared.Their electric conductivity decreased in the series ofsalts Mg>Li.>Zn>Na. The lower mobility of smaller ionsis explained by their stronger interaction with polymernetwork present in the gel.

National Repository of Grey Literature : 21 records found   beginprevious12 - 21  jump to record:
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