Electrical properties of novel Li4.08Zn0.04Si0.96O4 ceramic electrolyte at high temperatures

Novel Li4.08Zn0.04Si0.96O4 electrolyte was synthesized by citric acid-assisted sol-gel method. The compound was studied by X-ray diffraction and complex impedance spectroscopy in the frequency range from 10 Hz to 10 MHz and temperature range from 573 to 773 K. The conductivity-frequency spectra exhibited two regions of conductivity dispersion related to Li+ ion transport in the bulk and grain boundaries. The activation energy of the bulk conductivity was found to be equal to the activation energy of relaxation frequency in the bulk. This indicated that the increase in conductivity with temperature was due to the increase in ion mobility while the number of charge carrier concentration was found to be constant with selected temperature range. The observation was in agreement with the calculated charge carrier concentration and ion mobility derived from conductance spectra, sigma (ac)(omega) = sigma (o) + A omega (alpha) .