Controllable preparation and high ionic conductivity of Fe2O3-doped 46Li2O-4Al2O3-50P2O5 glass-ceramics

Lithium-ion conducting 46Li2O-4Al2O3-50P2O5 (mol.%) glass was prepared using melt-quenching method. Doping of Fe2O3 is aimed to improve the electrochemical properties of the glass-ceramics. Raman spectroscopy shows that partially replacing Li2O by Fe2O3 has a minor effect on the glass network structure. Thermal behaviors of the Fe2O3-doped Li2O-Al2O3-P2O5 glasses were studied by DSC. The effects of partial substitution of Fe2O3 on the thermal, chemical and electrical properties of the Li2O-Al2O3-P2O5 glass-ceramics were investigated. The results of XRD suggest that with increase of Fe2O3 content, the diffraction peaks of LiPO3 and AlPO4 gradually decrease, and the diffraction peak of high-conductive phase LiFePO4 increases gradually. The electrical conductivity lies in the range of 5.28-359 × 10−6 S/cm at room temperature. Moreover, the glass-ceramics had a high chemical stability to water. The addition of Fe2O3 to 46Li2O-4Al2O3-50P2O5 glass-ceramics improved the ionic conductivity, and the ionic conductivity of Fe2O3-doped glass-ceramics is nearly 70 times higher than Fe2O3-free one, which has a potential application as Li+ glassy solid electrolyte materials.