Insight into Electrical and Dielectric Relaxation of Doped Tellurite Lithium-Silicate Glasses with Regard to Ionic Charge Carrier Number Density Estimation.

We investigate the role of tellurite on a lithium-silicate glass 0.1 TeO -0.90.1 TeO -0.9 (LiO-2SiO) (LSTO) system proposed for the use in solid electrolyte for lithium ion batteries. The measurements of electrical impedance are performed in the frequency 100 Hz-30 MHz and temperature from 50 to 150 °C. The electrical conductivity of LSTO glass increases compared with that of LiO-2SiO (LSO) glass due to an increase in the number of Li ions. The ionic hopping and relaxation processes in disordered solids are generally explained using Cole-Cole, power law and modulus representations. The power law conductivity analysis, which is driven by the modified Rayleigh equation, presents the estimation of the number of ionic charge carriers explicitly. The estimation counts for direct contribution of about a 14% increase in direct current conductivity in the case of TeO doping. The relaxation process by modulus analysis confirms that the cations are trapped strongly in the potential wells. Both the direct current and alternating current activation energies (0.62-0.67 eV) for conduction in the LSO glass are the same as those in the LSTO glass.