Glass seals for sealing beta-alumina in electro-chemical cells or other energy conversion devices, glasses for use in such seals and cells or other energy conversion devices with such seals

摘要

A glass for sealing a beta-alumina tube in a sodium- sulphur cell has a composition suitable to resist attack by sodium at elevated temperatures and a coefficient of thermal expansion suitable for use with beta-alumina. The glass consists essentially of 28-48 mol % B₂O₃, 0-20 mol % SiO₂, 16-28 mol % Al₂O₃, together with 18-33 mol % of at least one alkaline earth oxide selected from the group consisting of BaO, SrO, CaO and MgO, the proportions of the constituents being such that the combined total of B₂O₃ and SiO₂ is 40 to 60 mol % and furthermore being such that 0.0517 A₁ + 0.0354 A₂ - 0.0063 A3 + 0.168 A4 + 0.1336 A₅ + 0.098 A₆ + 0.1597 A₇, lies between 5.7 and 6.4 where A₁, A₂, A₃, A₄, A₅, A₆ and A₇ are the respective molar percentages of B₂O₃, SiO₂, Al₂O₃, BaO, CaO, MgO and SrO.;A cell 30 sealed with such a glass seal is described with reference to Figure 8.