B2O3 as an effective sintering aid in enhancing the lithium-ion conductivity of LiTa2PO8 solid electrolyte

LiTa2PO8 (LTPO) is a newly developed oxide-type solid electrolyte. It is found to exhibit good ionic conductivity (>10−4 S/cm) at room temperature, making it suitable for application in all-solid-state Li-ion batteries. However, there are not many studies conducted on this material. In this study, we investigate the effects of B2O3 sintering aid on the various properties of LTPO synthesized via the solid-state reaction method. The samples containing three different concentrations of B2O3 (0.5, 1, and 1.5 wt%) are synthesized at various sintering temperatures ranging from 850 °C to 1050 °C. The various sample properties are characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and impedance spectroscopy techniques. The highest total ionic conductivity among all the samples is found to be 3.55 x 10−4 S/cm for LTPO containing 1 wt% B2O3 sintered at 950 °C. This ionic conductivity value is around 3.5 times higher than that of pure LTPO and is obtained at a relatively lower sintering temperature compared to pristine LTPO.