Effect of B2O3 content on structure-function of vanadium‑lithium-borate glasses probed by synchrotron-based XAS and vibrating sample magnetrometry technique

Abstract In this work, vanadium‑lithium-borate glasses, 0.5V2O5–0.5(Li2O-xB2O3) with x = 1.0, 2.0 and 3.0, respectively, were prepared by conventional melt-quench technique. The glass samples were characterized by X-ray diffraction, scanning electron microscopy, X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, UV–Visible Spectroscopy and vibrating sample magnetrometry. X-ray absorption near-edge spectra at the V K-edge confirmed the presence of the mixing of V4+ and V5+ oxidation states and X-ray photoelectron spectroscopy were used to quantify and reveal the amount of V4+ and V5+ in the glass samples with approximately a ratio of 1:4 for V4+:V5+. The paramagnetic behavior were found for the glass samples with x = 1.0 and 2.0 due to the presence of V4+. However, an influence of B2O3 content clearly affected to the glass sample with x = 3.0 resulting to a diamagnetic nature of this glass composition. The local structural information around V atoms in all glass samples were addressed using extended X-ray absorption fine structure technique with a mean oxygen coordinated network of 3.50(1). The notable properties of these glasses can be used and applied in the energy storage applications.