Conduction Characteristics of the Lithium Iodide-Aluminum Oxide Solid Electrolytes

Abstract

The conduction characteristics of the polycrystalline lithium iodide containing aluminum oxide were studied. It was found that the incorporation of aluminum oxide substantially increased the conductivity of lithium iodide. Lithium iodide containing 33–45 mole per cent (m/o) aluminum oxide exhibited conductivities in the order of 10−5 ohm−1 cm−1 at 25° ± 2°C. Inasmuch as no substantial amount of aluminum oxide was found soluble in the lithium iodide under the experimental conditions, the increase in conductivity could not be explained by the classical doping mechanism. The electronic conductivity of the lithium iodide-aluminum oxide solid was negligible compared to the ionic conductivity. Therefore, it is suitable as a solid electrolyte in solid-state battery systems.