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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.
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Tribological Behaviour of Plasma Sprayed Al2O3 and Cr2O3 Coatings
Řidký, V. ; Dubský, Jiří ; Cejp, J.
Plasma sprayed ceramics coatings are well known for their wear resistance.Plasma sprayed alumina and chromia oxide coatings are widely used to improve the resistance of metallic components against various types of wear and corrosion[1,2].However, the particular structure of plasma-sprayed coatings(high porosity,cracks,nehomogenity etc.) affects their mechanical properties.
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Microscopic characterization of graphene material and electronic quality across neighbouring, differently oriented copper grains
Čermák, Jan ; Yamada, T. ; Ganzerová, Kristína ; Rezek, Bohuslav
We study graphene grown across the boundary of three such grains having bright, medium, and dark color in reflection. Raman micro-spectroscopy proves presence of mostly a monoor bi-layer graphene on all the grains. Yet intensity of Raman 2D band is grain-dependent: highest at the darkest grain and lowest at the brightest one. Contrary, conductive atomic force microscopy detects the highest conductivity at the brightest grain and the lowest current at the darkest grain. This is attributed to dominant electrical current path through graphene and underlying oxide thickness of which also depends on the type of copper grain. We correlate and discuss the results with view to better understanding of graphene growth and electronic properties on large area copper substrates.
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