| Abstract [eng] |
Solid electrolytes of pyrophosphate and perovskite structure are investigated in this dissertation. The electrical properties of solid electrolytes both impedance and electric conductivity were studied in broad frequency range (from 10 Hz to 10 GHz) and wide temperature interval (from 300 K to 830 K) by sophisticated material characterization method – impedance spectroscopy. Dispersions of electrical properties, caused by charge carrier relaxation in electric field, were observed and analysed in the obtained spectra. Advantages of wide frequency and temperature intervals allowed us to investigate the peculiarities of charge carriers’ transport within the ceramics grains and grain boundaries. This analysis in conjunction with XRD and DTA measurements let us to confirm both phase transitions and proton conductivity phenomenon in some sodium based pyrophosphates, and also to relate charge carrier (Li+ cation) mobility and stoichiometric factor y in Li0.5-yNayLa0.5Nb2O6 niobates which have defected perovskite crystal structure. Some investigated materials were found to be attractive cathodic materials for all solid state battery applications. |
