LiF doping improving the ionic conductivity of the Li_1.1Ta_0.9Zr_0.1SiO₅ solid electrolyte at room temperature

LiTaSiO₅ (LTSO) is a new type of fast ionic conductor. However, current synthesized electrolytic samples have lower ionic conductivity at room temperature. The Li_1.1Ta_0.9Zr_0.1SiO₅ solid electrolyte was prepared by the solid-phase synthesis method, and the effect of LiF doping on the structure and performance of such electrolyte material was studied in this paper. The results showed that LiF doping improved the crystallinity of crystals, promoted crystal growth, and then reduced the number of grain boundaries, which significantly reduced the porosity and increased the density of electrolyte samples. As a result, it could reduce the crystal particle and grain boundary resistance of electrolyte samples, facilitate the rapid migration of lithium ions among crystal particles and grain boundaries, and improve the overall ionic conductivity of the material. When x=0.4, its relative density reached 90.81%, the total ionic conductivity was 8.31×10^-5 S/cm, and the diffusion activation energy reached 0.203 eV, which was nearly two times higher than that of the undoped samples.