Characterization and electrochemical cell characteristics of mechanochemically synthesized AgI–Ag2O–MoO3 amorphous superionic system

Abstract

Mechanochemically synthesized amorphous and thermally stable xAgI(100−x)[0.5Ag2O+0.5MoO3] system for x=40, 50, 60 and 70 shows high ionic conductivity of ∼10−2–10−3 Ω−1 cm−1 at room temperature. The highest ionic conductivity is achieved for 36 h milled sample containing 50 m/o AgI, which is more than three orders of magnitude higher than that of crystalline AgI at room temperature and comparable with the glassy fast ionic conductor of the same composition prepared by conventional quenching. The samples are thermally stable at least up to ∼70 °C with ionic transport number near unity. These amorphous samples are further characterized by distinct glass transition as well as amorphous⇒crystalline transition temperatures. The FT-IR spectra confirm the presence of MoO42− and Mo2O72− groups in the ball-milled systems. Investigations on galvanic cells of the type Ag|a-SIC|I2+C reveal that these mechanochemically synthesized amorphous samples are stable under battery conditions and the cell performance parameters are comparable with those of earlier investigated Ag/I2 cells prepared using glassy SICs.