Beta-alumina solid electrolyte
Beta-alumina solid electrolyte (BASE) is a fast ion conductor material used as a membrane in several types of molten salt electrochemical cell. Currently there is no known substitute available.
β''-Alumina (beta prime-prime alumina) is an isomorphic form of aluminium oxide (Al2O3), a hard polycrystalline ceramic, which, when prepared as an electrolyte, is complexed with a mobile ion, such as Na, K, Li, Ag, H, Pb, Sr or Ba depending on the application. Beta-alumina is a good conductor of its mobile ion yet allows no non-ionic (i.e., electronic) conductivity.