Effect of boron oxide on the ionic conductivity of the Li<sub>1.2</sub>Al<sub>0.2</sub>Zr<sub>0.1</sub>Ti<sub>1.7</sub> (PO<sub&amp

Boron oxide is considered as a good dopant for improving the ionic conductivity of solid electrolytes. This effect is usually attributed to the optimization of grain boundary conductivity. In this work, the effect of addition of 1–4 wt. % boron oxide on the ionic conductivity of Li1.2Al0.2Zr0.1Ti1.7(PO4)3 with the NASICON structure was investigated. The obtained materials were characterized by XRD, SEM, Raman spectroscopy, IR spectroscopy, impedance spectroscopy and MAS 27Al, 7Li, 31P and 11B NMR. It was shown that the introduction of B2O3 at the stage of synthesis of Li1.2Al0.2Zr0.1Ti1.7(PO4)3 leads to the production of materials doped with boron ions. The highest conductivity (2.9 × 10–4 S/cm) at 25°C is characteristic of the sample with 2 wt. % boron oxide. At the same time, when B2O3 is added to the already prepared phosphate, it is predominantly localized at the interfaces, leads to the release of LiTiPO5 impurity and does not have a significant effect on the conductivity of the prepared samples.