New synthesis route for glasses and glass-ceramics in the Ga2S3Na2S binary system

Compositions belonging to the binary system (100-x)[Ga2S3]-x[Na2S] (with 10 ≤ x ≤ 90) were synthesized by mechanical-alloying. By using the ball-milling technique instead of a usual heating process, the vitreous domain is extended from 24 ≤ x ≤ 41 to 20 ≤ x ≤ 80. For the first time the conductivity of these glasses has been measured by impedance spectroscopy and an ionic conductivity of 1.9 × 10−6 S.cm−1 at 25 °C is achieved for x = 80. A glass-ceramic processing from the Na2S richest glass composition is implemented in order to stabilize the sample and to eliminate Na dendrite formation that occurs in the glass during DC current experiments. Finally, this paper shows the positive impact of crystallization and reveals that the glass-ceramization is an interesting process in the framework of synthesis of electrolytes for all-solid-state sodium batteries.