Ionic conductivity (solid state)

Ionic conductivity (denoted by λ) is a measure of a substance's tendency towards ionic conduction. This involves the movement of an ion from one site to another through defects in the crystal lattice of a solid or aqueous solution. Ionic conduction is one mechanism of current. In solids, ions typically occupy fixed positions in the crystal lattice and do not move. However, ionic conduction can occur, especially as the temperature increases. Materials exhibiting this property are used in batteries. A well-known ion conductive solid is β''-alumina ("BASE"), a form of aluminium oxide. When this ceramic is complexed with a mobile ion, such as Na +, it behaves as so-called fast ion conductor. BASE is used as a membrane in several types of molten salt electrochemical cell.