Thermal, structural and electrical properties of fluorine-doped Li3.6Al0.8Ti4.0P7.6O30-x/2Fx (x = 0, 0.5, 1, 2) glass-ceramic electrolytes

• Published in: Journal of alloys and compounds 2021-02, Vol.853, p.1, Article 157191
• Main Authors: Xu, Wenjing, Qin, Chunchun, Zhang, Simin, Liang, Haozhang, Lei, Weicheng, Luo, Zhiwei, Lu, Anxian
• Format: Article
• Language: English
• Subjects: Bricklayer model; Crystal structure; Crystallinity; Crystallization; Electrical conductivity; Electrical properties; Electrical resistivity; Electrochemical analysis; Electrolytes; Fluorine; Fluxing; Glass; Glass ceramics; Infrared spectroscopy; Microstructure; Room temperature; Solid electrolytes
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.157191

The fluorine-doped Li3.6Al0.8Ti4.0P7.6O30-x/2Fx (x = 0, 0.5, 1, 2) glasses were prepared by the melt-quenching method, to investigate the effect of different fluorine doping content on the electrochemical performance after crystallization. The FT-IR spectroscopy was used to investigate the characteristics of glass-forming structural units. DSC results show that ΔT (Tc-Tg) decreases from 83 °C to 58 °C with the increase of fluorine content, indicating an increase in the crystallization trend. XRD analysis confirmed the amorphous nature of the obtained glasses. Diffraction characteristic peaks of all annealed glass-ceramics match well with the crystalline phase LiTi2(PO4)3 with rhombohedral NASICON-type structure. The Li3.6Al0.8Ti4.0P7.6O29.75F0.5 glass-ceramics obtained at 900 °C acquire the optimal conductivity at room temperature, which reaches a maximum value of 3.85 × 10−5 S cm−1. It is mainly attributed to that fluoride as a fluxing agent, is beneficial to the precipitation of the conductive crystalline phase, thereby promoting the precipitation of the conductive crystalline phases. •F-doped Li3.6Al0.8Ti4.0P7.6O30-x/2Fx (x = 0, 0.5, 1, 2) glass-ceramics were prepared.•XRD confirms the main crystalline phase of LiTi2(PO4)3 with NASICON-type structure.•F-doping can inhibit the precipitation of heterogeneous phases AlPO4 and LiTiOPO4.•The R.T. conductivity of Li3.6Al0.8Ti4.0P7.6O30-x/2F0.5 is high as 3.85 × 10−5 S/cm.