Glasses with unusually high ionic conductivity at a room temperature have been studied for many years by reason of their application in various electro chemical solid state devices such as rechargeable batteries and chemical sensors. New fast ion-conducting glasses were prepared in the basic system CuI-Cu20-Mo03 by replacing Mo03 with V205 and/or WO3. The glasses exhibited a high ionic conductivity at 25 deg C in the range 0.22 to 0.87 S m-1 and much lower electronic conductivity, which was at least four orders of magnitude lower than the ionic conductivity. CuI positively affected the ionic conductivity, but decreased both glass forming ability and glass stability. Glass forming ability and stability of the glasses were improved by adding V205.
