Sol-gel synthesis, characterization and impedance studies of lithium borosilicate glass

Densified xerogels of lithium borosilicate (LBS) were synthesized through sol-gel process by varying modifier to formers (m/f) ratios. XRD and FTIR spectra were recorded for dried LBS gel samples heat-treated at different temperatures and the gel to glass to crystalline changes were studied. Also, all LBS samples were characterized by XRD, FTIR and DSC techniques. Impedance measurements were made on all LBS samples at different temperatures and the impedance data were analyzed using Boukamp equivalent circuit software. Conductivity of each m/f ratios of LBS samples were calculated from the analyzed impedance data and 20% Li₂O-80% [0.2 B₂O₃ + 0.8 SiO₂] composition showed the best conductivity σ = 8.83 (±0.02) × 10⁻⁸ Scm⁻¹ at 443 K. The activation energy (E_a) is obtained from the temperature dependent of conductivity data fitted to Arrhenius equation and it is found to be 0.64 eV (±0.02). The observed variation of conductivity with m/f ratios of LBS samples was explained using weak electrolyte model.