| abstract |
A solid ionic conductor material, sujtable for use as a solid electrolyte in an alkali metal-sulphur battery, is in the form of a glass ceramic prepared by crystallisation from a glass derived from a composition comprising at least one alkali or alkaline earth metal borate selected from lithium, sodium, potassium, calcium and magnesium borates and at least one source of halogen selected from metal chlorides, bromides and iodides. |