Synthesis and characterization of some molybdenum-containing glass-ceramics

This study aims at investigating the role of MoO3 and Al2O3 on the crystallization characteristics and properties of some lithium disilicate glasses. A reduction in glass transition temperature (Tg) was observed when silica was substituted with molybdenum. However, the Tg increased with the addition of aluminum oxide. This reduction is because of the structural changes accrued on the glass network coherence. X-ray powder diffraction (XRD) results show that lithium metasilicate, lithium disilicate, lithium orthomolybdate, and β-spodumene solid-solution phases were crystallized by controlled crystallization of the glasses. In addition, the XRD patterns show that β-spodumene can accommodate molybdenum in its structure. Consequently, it would result in a decrease in the lithium orthomolybdate phase within the crystallization prouduct. The MoO3/SiO2 substitution decreases the ionic conductivity and chemical stability of the resultant crystalline materials. In contrast, the addition of different amounts of Al2O3 to 34.83 Li2O–4MoO3–61.17 SiO2 glass enhances the ionic conductivity and improves the chemical durability of the glass-ceramic. Thermal expansion coefficients (CTE) of the glass-ceramic range from 53 × 10−7 to 109× 10−7 K−1 over the temperature range, 25–700 °C. The synthesized glass-ceramic will be used as a solid electrolyte for lithium-ion batteries.