Several samples of ion-conducting silver phosphate glasses doped with zinc/cadmium halides are prepared and subjected to X-ray diffraction analysis, transference number measurement, and electrical conductivity studies. The percentage transference numbers of these glasses are found to lie between 98.3 and 99.3, which suggests that the glasses are essentially ionic conductors. The conductivity values range from 1.66×10−2 to 8.66×10−2 Scm−1 at 300°C. Solid-state batteries using these glassy systems as electrolytes with the cell configurations Ag||Ag2OP2O5(20%)Zn/CdX2||(C+I2) and Ag||Ag2OP2O5(20%)Zn/CdX2||(C+I2+electrolyte) (where X is Cl, Br or I) have been fabricated and their discharge characteristics studied. Cells with undoped silver phosphate glasses as electrolytes have also been prepared and studied. The addition of Zn/CdX2 to silver phosphate glass results in a substantial increase in the open-circuit voltage in the order MI2>MBr2>MCl2 (where M is the dopant cation). Cells with Ag||Ag2OP2O5(20%)Zn/CdI2||(C+I2+electrolyte) deliver the best performance.