Preparation of silver ion conducting amorphous materials in the system Ag2S–SiS2 by mechanical milling processes

Silver ion conducting amorphous materials in the system Ag2S–SiS2 were synthesized over the composition range from 0 to 60 mol% Ag2S by use of a high-energy ball-milling process. The electrical and electrochemical properties of the obtained samples were evaluated by using ac impedance spectra, dc polarization measurements, and cyclic voltammetry. These measurements suggested that the silver-ion conductivities of the samples increased with an increase in the Ag2S content and that the activation energy for conduction decreased with an increase in the Ag2S content. The 60Ag2S·40SiS2 (mol%) sample showed its highest ion conductivity, 6.9 × 10−2 S m−1, at 298 K in the system Ag2S–SiS2. This sample also possessed a wide electrochemical window over 2.0 V vs. Ag/Ag+.