Investigating the Crystallization Process of Boron-Bearing Silicate-Phosphate Glasses by Thermal and Spectroscopic Methods

Abstract

Glasses and devitrificates from the SiO2–B2O3–P2O5–K2O–CaO–MgO system with constant contents of SiO2 and P2O5 network formers, modified by the addition of B2O3, were analyzed. All materials were synthesized by the traditional melt-quenching technique. The glass stability (GS) parameters (Krg, ∆T, KW, KH) were determined. The effect of the addition of B2O3 on the GS, liquation phenomenon, crystallization process, and the type of crystallizing phases were examined using SEM-EDS, DSC, XRD, and Raman spectroscopy imaging methods. It was observed that the addition of B2O3 increased the tendency of the glass to crystallize. Both phosphates (e.g., Ca9MgK(PO4)7, Mg3Ca3(PO4)4), and silicates (e.g., K2Mg5(Si12O30), CaMg(Si2O6), MgSiO3) crystallized in the studied system. The Raman spectrum for the orthophosphate Mg3Ca3(PO4)4 stanfieldite type was obtained. Boron ions were introduced into the structures of crystalline compounds at high crystallization temperatures. The type of crystallizing phases was found to be related to the phenomenon of liquation, and the order of their occurrence was dependent on the Gibbs free enthalpy.

Borate-Based Compounds as Mixed Polyanion Cathode Materials for Advanced Batteries

“…This exhibits the versatility of BSiO to conform to a wide variety of frameworks. However, the majority of reported BSiOs in the literature are on the discovery of natural BSiO minerals, the applications of synthetic BSiO glasses, and the modification of silicate glasses with boron additives [162][163][164]. However, Li 3 Mo(BO 3 )(SiO 4 ), Li 3 V(BO 3 )(SiO 4 ), and Li 3 Bi(BO 3 )(SiO 4 ) (Table 4) from Li-exchanged Na-based sidorenkite structure were recommended for investigation as cathode materials for secondary LIBs [19].…”