JOINT GLASS TO FORM SODIUM-SULFUR BATTERY AND JOINT OF CYLINDRICAL SOLID ELECTROLYTE WITH BOTTOM TO INSULATION RING USING SAME

摘要

PURPOSE:To improve joint strength by using joint glass including specified chemical components and having a specified thermal expansion coefficient. CONSTITUTION:An outer circumferential part 13 of an aperture part 12 of beta-alumina tube 10 of a cylindrical solid electrolyte 15 having a bottom forming a sodium-sulfur battery is jointed with an insulation ring 11 by a joint glass ring 13. This ring 13 is formed of glass of which thermal expansion coefficient is smaller than that of the electrolyte 15 and the ring 11, having a difference of less than 20X10-7/ deg.C between the thermal expansion coefficient at the glass transition temperature and that of the electrolyte 15, and including chemical components of SiO2, Al2O3, NaO and B2O3 at least, so the tensile stress by a residual stress at the joint part becomes small, while the overhang bend strength becomes strong. As a result, the joint strength is increased.