Electrochemical performance study of AlF₃-containing lithium phosphate glass electrolytes

This study aims to enhance the performance of Li₂O-P₂O₅-based lithium phosphate glass electrolytes for all-solid-state lithium batteries by incorporating aluminum fluoride (AlF₃). Initially, Li₂O-P₂O₅ glass was melted, followed by the addition of stoichiometric AlF₃, and remelted to achieve an optimized composition of 10AlF₃⋅50Li₂O⋅40P₂O₅. By adjusting the melting temperatures and the ratios of raw materials, we explored different synthesis procedures and obtained the lithium fluoro-phosphate glass electrolytes and systematically investigated their physicochemical properties and electrochemical performance. Its physicochemical properties include the glass composition, NMR spectra, and glass transition temperature. Symmetrical cell tests conducted at high current densities demonstrated that the incorporation of AlF₃ significantly enhanced the stability of the interface with lithium metal, maintaining excellent cycling performance. Furthermore, the doping with AlF₃ did not reduce the ionic conductivity of the original Li₂O-P₂O₅-based glass electrolyte, and the activation energy remained unchangeable. • Evaluation properties of AlF₃-containing Li₂O-P₂O₅ glass electrolytes. • AlF₃ does not affect the physicochemical properties of glass electrolyte. • AlF₃ enhances interfacial stability of glass electrolyte and lithium metal.