Effect of flux B₂O₃ on structure and properties of LATP solid electrolyte

Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) has become a promising solid electrolyte material for energy storage due to its high ionic conductivity, low cost, and good air stability. However, its application development is limited by the problems of high grain boundary resistance and low density. In this work, the boron-based B₂O₃ glass are added into LATP by solid method at external concentrations of 1 wt%, 2 wt%, 3 wt% and 4 wt%. And the effect of B₂O₃ on the structure and properties of LATP solid electrolyte was studied. As the results, the main diffraction peaks of all prepared samples sintered at 850 °C for 7 h maintain the NASICON-type with the R-3c space group. Meanwhile, the symmestric stretching vibrations of P–O bond is redshifted with the addition of boron-based glass, which plays a positive role in bulk conductivity. Additionally, high density can be obtained by controlling the amount of flux, while controlling the production of the second phase LiTiPO₅ and reducing the influence of the second relative ionic conductivity. When the amount of B₂O₃ is 2 wt%, the relative density, total ionic conductivity and conductance activation energy are the best: σ_tot = 0.307 mS/cm, ρ = 95.1%, Ea = 0.26 eV.