Composite ceramic structure for use in a sodium sulphur cell

摘要

In a sodium sulphur cell, the electrolyte element of beta alumina has a non metallic element bonded to it by a seal formed of glass-ceramic. A glass ceramic seal is made by sealing in the normal way with an alumina-borate glass with an alkaline earth oxide modifier and then heat treating the glass seal to encourage nucleation of crystals and subsequently to encourage crystallisation. The glass used should be free of alkali metal oxide but should include a nucleating agent such as PO25 or TiO2.