Solid Electrolyte Membranes Based on Li2O-Al2O3-GeO2-SiO2-P2O5 Glasses for All-Solid State Batteries

Rechargeable Li-metal/Li-ion all-solid-state batteries due to their high safety levels and high energy densities are in great demand for different applications ranging from portable electronic devices to energy storage systems, especially for the production of electric vehicles. The Li1.5Al0.5Ge1.5(PO4)(3) (LAGP) solid electrolyte remains highly attractive because of its high ionic conductivity at room temperature, and thermal stability and chemical compatibility with electrode materials. The possibility of LAGP production by the glass-ceramic method makes it possible to achieve higher total lithium-ion conductivity and a compact microstructure of the electrolyte membrane compared to the ceramic one. Therefore, the crystallization kinetics investigations of the initial glass are of great practical importance. The present study is devoted to the parent glasses for the production of Li1.5+xAl0.5Ge1.5SixP3-xO12 glass-ceramics. The glass transition temperature T-g is determined by DSC and dilatometry. It is found that T-g decreases from 523.4 (x = 0) to 460 degrees C (x = 0.5). The thermal stability of glasses increases from 111.1 (x = 0) to 188.9 degrees C (x = 0.3). The crystallization activation energy of Si-doped glasses calculated by the Kissinger model is lower compared to that of Si-free glasses, so glass-ceramics can be produced at lower temperatures. The conductivity of the glasses increases with the growth of x content.

Automated summary

This study investigates the parent glasses for the production of Li1.5+xAl0.5Ge1.5SixP3-xO12 glass-ceramics for rechargeable Li-metal/Li-ion all-solid-state batteries. It is found that Si-doped glasses have lower crystallization activation energy compared to Si-free glasses, enabling the production of glass-ceramics at lower temperatures.