The Impact of Boron Compounds on the Structure and Ionic Conductivity of LATP Solid Electrolytes.

The increasing demand for safe and high-energy-density battery systems has led to intense research into solid electrolytes for rechargeable batteries. One of these solid electrolytes is the NASICON-type Li 1+x Al x Ti 2-x (PO 4 ) 3 (LATP) material. In this study, different boron compounds (10% B 2 O 3 doped, 10% H 3 BO 3 doped, and 5% B 2 O 3 + 5% H 3 BO 3 doped) were doped at total 10 wt.% into the Ti 4+ sites of an LATP solid electrolyte to investigate the structural properties and ionic conductivity of solid electrolytes using the solid-state synthesis method. Characterization of the synthesized samples was conducted using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The XRD patterns of the boron-doped LATP (LABTP) samples show that the samples have a rhombohedral phase with space group R3¯c together and low amounts of impurity phases. While all the LABTP samples exhibited similar ionic conductivity values of around 10 -4 S cm -1 , the LABTP2 sample doped with 10 wt.% H 3 BO 3 demonstrated the highest ionic conductivity. These findings suggest that varying B 3+ ion doping strategies in LATP can significantly advance the development of solid electrolytes for all-solid-state lithium-ion batteries.