Identification of the presence of crystalline phase in lithiated boron oxide ionic glass conductors

The presence of crystalline phase in low and medium lithium content boron oxide glasses xLi2O–B2O3, with x = 0.3–2.5, has been detected by combined infrared and impedance measurements. The borate glass samples apparently consist of one single phase, the vitreous. However, characteristic absorption bands appearing in infrared spectra of samples with x ≥ 0.8 indicate the presence of crystalline Li2O. Further evidence is provided by the gradual appearance and disappearance with increasing temperature of an additional electrical relaxation in impedance spectra, corresponding to the crystalline phase present in the borate glasses, which is associated with Li2O.