Effect of Hold Time on Electrical Properties of Lithium Zinc Borate Glass Ceramics for Energy Storage Applications

Conductivity spectra of heat-treated 50B₂O₃·30Li₂O·20ZnO glass samples for different hold times, 2 h, 4 h, 6 h, and 8 h, were investigated across a wide temperature range (413–573 K) and frequency range (0.1–10⁶ Hz). Parameters like crossover frequency (ω_H), frequency exponent (s), and direct current conductivity (σ_dc) have been retrieved from the Almond West model fit of the experimental data of ac conductivity. The applicability of overlapping large polaron tunneling has been observed in the examined glass ceramics system. The activation energy determined from the conductivity, electric modulus, and impedance analysis shows a consistent trend. The glass composition 50B₂O₃·30Li₂O·20ZnO exhibits the highest value of conductivity ~ 8.3 × 10⁻⁶ Scm⁻¹ when crystallized for 4 h at 573 K, making it an ideal choice for electrode material in energy storage devices. An enhancement in electrical conductivity was observed by converting the 50B₂O₃·30Li₂O·20ZnO glass samples into glass ceramics. Formation of the layered structure was observed from SEM micrographs, which indicates that the studied glass ceramics are appropriate for electric double-layer capacitance fabrication (EDLC).