Investigation of the physical, thermal, and dielectric relaxation of bismuth zinc phosphate glasses modified with lithium ions for possible energy storage applications

Mixed ionic-electronic xLi₂O-(1-x)[0.25Bi₂O₃-0.35ZnO-0.30P₂O₅] (x = 0.05, 0.15, 0.25, 0.35, and 0.45) glasses have been formed by melt-quenching procedure to examine their physical, thermal, and dielectric characteristics. The physical investigation exposed that the density decreases from 5.23 to 4.74 g·cm⁻³ with the addition of Li-ions into the glassy matrix. Thermal investigations have been carried out using DSC technique. The values of Glass transition temperature (368.21–301.65) °C, and peak crystallization temperature (561.61–511.21) °C are observed to decrease with the addition of Li₂O content. Conductivity spectra of as-prepared samples have been studied in frequencies ranging from 20 Hz to 2 MHz temperature range of 373–513 K. It becomes apparent that when the temperature rises, the dielectric loss and dielectric constant of the systems under study decrease. The quantities of dielectric loss and dielectric constant are projected to escalate with increasing temperature while diminishing with higher frequencies. The Kohlrausch–Williams–Watts model is employed to analyze the relaxation process in glass samples. This model demonstrates that the charge carriers adhere to non-Debye-type relaxation. Some thermodynamic parameters linked with the dielectric relaxation process have also been investigated. Impedance spectroscopy analysis suggests that electric conduction arises via Li and electrons/polarons, which makes the studied materials appropriate for energy storage applications.