Electrochemical properties of the amorphous solid electrolytes in the system Li2S–Al2S3–P2S5

Lithium-ion conducting solid electrolytes in the composition (100-x)Li3PS4·xLiAlS2 (mol%) were prepared by the use of a high-energy ball-milling process at room temperature. Amorphous samples were obtained in the composition range of x = 0 to x = 13.1. In the composition of x ≥ 18.2, a crystalline Al2S3 phase remained in the samples which were ball-milled for 35 h. The lithium ion conductivity at 298 K of the obtained amorphous samples was increased with an increase in the compositional parameter x and showed the maximum at the compositional parameter x = 13.1 (86.9Li3PS4·13.1LiAlS2: σ298K = 6.0 × 10− 4S cm− 1 at 298 K).