Glass sealing materials for sodium-sulfur batteries and batteries made therewith

• US 5,158,840 A
• Filed: 03/11/1991
• Issued: 10/27/1992
• Est. Priority Date: 03/11/1991
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Megerle, Clifford A.
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US07/667,157
• Time in Patent Office: 596 Days
• Field of Search: 429/104, 429/185, 501/49, 29/623.2
• US Class Current: 429/104
• CPC Class Codes: C03C 3/14 containing boron
• CPC Class Codes: C03C 8/24 Fusion seal compositions being frit compositions having non-frit additions, i.e. for use as seals between dissimilar materials, e.g. glass and metal; Glass solders
• CPC Class Codes: H01M 10/3909 Sodium-sulfur cells
• CPC Class Codes: H01M 50/191 Inorganic material
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/4911 including sealing

Abstract

A glass composition having a composition between about 18 and about 23 mole % Na₂ O, about 3 to about 7 mole % Cs₂ O, the balance being B₂ O₃ is adaptable to match the thermal expansion coefficient of a beta"-Al₂ O₃ solid electrolyte when used to bond and seal the solid electrolyte to a porous support plate (22) in a sodium-sulfur battery (10).

Claims

1. A separator for use in a sodium-sulfur battery, the separator comprising a solid electrolyte;

a glass seal, wherein the glass comprises from 18-23 mole % Na₂ O, from 3-7 mole % Cs₂ O and the balance B₂ O₃ ; and

a porous support plate, wherein the glass seal bond and seals the solid electrolyte to the porous support plate.

2. The separator of claim 1, wherein the B₂ O₃ comprises about 75 mole %.

3. The separator of claim 1 wherein the Na₂ O comprises from 19-21 mole % and the Cs₂ O comprises from 4-6 mole %.

4. The separator of claim 1 wherein the solid electrolyte comprises beta"-Al₂ O₃ and the porous support plate is formed of a material selected from the group consisting of graphite and fused titania.

5. In a sodium-sulfur battery having a separator, a method of sealing the separator, comprising the steps of:

providing a solid electrolyte;

depositing a sealing glass on the electrolyte, wherein the glass comprises from 18-23 mole % Na₂ O, from 3-7 mole % Cs₂ O and the balance B₂ O₃ ;

providing a porous support plate on the sealing glass; and

heating the assembled structure so as to fuse the glass to the solid electrolyte and the support plate.

6. The method of claim 5 wherein the solid electrolyte comprises beta"-Al₂ O₃ and the porous support plate is formed of a material selected from the group consisting of graphite and fused titania.