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Lithium Phosphate Glasses stabilized with Tungsten Oxide
Míka, M. ; Mladonický, P. ; Vondrák, Jiří ; Stopka, Pavel ; Klápště, Břetislav
Glass exhibiting an increased ionic conductivity could be an attractive material for the construction of electrochemical solid-state devices such as ion-selective sensors, batteries, fuel cells, and electrochromic devices. In these devices the glass can function as a membrane, solid electrolyte or electrode if shows mixed electric conductivity. Amorphous nature gives glass considerable advantages comparing to polycrystalline materials.If we use chemical composition systems with a good glass-forming ability, we can add many different cations and this way "tune" glass properties. Because a large portion of glass volume is occupied by oxygen atoms, many glass properties are strongly influenced by the state of oxygen atoms, especially by the the electron density. God glass-forming ability is exhibited for example by alkali-phosphate glass.
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Gel Polymer Electrolytes
Vondrák, Jiří ; Sedlaříková, M. ; Nováček, T. ; Reiter, J.
The research and development of lithium and lithium ion batteries, the necessity of a new kind of electrolytes appeared. These electrolytes have to be strictly aprotic and reasonably conducting at the same time, and the mechanism of conduction must be based on the mobility of Li+ cations.
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Electrochemistry in the Medium of PMMA Gel Electrolytes
Reiter, Jakub ; Vondrák, Jiří ; Sedlaříková, M. ; Velická, Jana ; Nečesal, P.
Polymer gel electrolytes are used in the electrochemistry of lithium batteries and electrochromic devices. Their investigation started in our department in 1997, when first results were published on the International Seminar on Inclusion Compounds. Investigation of electric conductivity showed, that the specific conductivity of a 0.25 M LiBF4 solution was not lowered by an addition of solid PMMA polymer more than by 40-50%. We have developed a new method preparation of gel polymer electrolyte: after a mixung of anhydrous perchlorate solution in propylencarbonate (lithium, sodium, cadmium and other sals) with monomeric and oligomeric metylmetacrylate we hawe obtained an elastic and homogenous polymer with good optical properties.
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