Anomalies of some physical properties and electrochemical performance of lithium–lead–germanate glasses

Abstract The purpose of this paper was to approach the structure–properties interrelationship of lithium–lead–germanate glasses in order i) to understand the structural mechanism responsible for the germanate anomaly; ii) to determine some physical properties such as density, optical gap energy, refractive index; iii) to find electrochemical performance of the studied glasses. The studied homogeneous glass system has the xLi 2 O·(100 − x)·[7GeO 2 ·3PbO] composition where 0 ≤ x ≤ 40 mol%Li 2 O. Our results show that the contracting effect of lithium ions causes the enhancement of density and reduction of molar volume of glass samples. By increasing lithium ions content up to 10 mol%, major changes in FTIR spectrum of glass introduce lithium ions as network modifiers. Accordingly, the increase of lithium ions concentration up to 20 mol% turns on the modification in density, gap energy and refractive index values. By taking these under consideration, it would be noted that network modifying role of the lithium ions affects the properties (density, optical gap energy, refractive index) more than GeO 4 /GeO 6 ratio. The conductivity and electrochemical performances of the glass system with 20Li 2 O·80[7GeO 2 ·3PbO] composition were demonstrated.