Brazed ceramic seal for batteries
This invention is a sealed battery case and a method for making it, including a brazed ceramic ring that separates the positive and negative ends of the battery while providing a leak-tight seal. A brazing material is used that comprises greater than 50% gold. The case is strong, and can be negative, neutral, or positive, withstanding more than 3.5 V vs. Li/Li + .
1. A battery comprising:
a battery case including
a first ring that includes a ceramic material,
a second ring sealed to the first ring, the second ring including a first metal and being bonded to an open end of a cylinder, and
a third ring sealed to the first ring, the third ring being bonded to a cap for the battery case
electrodes housed in the battery ease such that the cylinder surrounds the electrodes; and
an electrolyte activating the electrodes in the battery case.
2. The battery of claim 1 , wherein the battery case includes a positive current carrying element of the battery.
3. The battery of claim 2 , wherein the positive current carrying clement exhibits more than 3.5 V vs. Li/Li + .
4. The battery of claim 2 , wherein the positive current carrying element exhibits more than 4.1 V vs. Li/Li + .
5. The battery of claim 2 , wherein the positive current carrying element exhibits more than 4.3 V vs. Li/Li + .
6. The battery of claim 1 , wherein the battery is a lithium battery.
7. The battery of claim 1 , wherein the end cap is negatively charged.
8. The battery of claim 1 , wherein the cylinder has a closed end.
9. The battery of claim 1 , wherein the cap includes a feedthrough hole.
10. The battery of claim 1 , wherein the second ring is bonded to the open end of the cylinder such that a lower edge the second ring is on top of an upper edge of the cylinder.
11. The battery of claim 1 , wherein the third ring is bonded to the cap such that the cap is on top of an upper edge of the cylinder.
12. The battery of claim 1 , wherein the first ring is positioned between the second ring and the third ring.
13. The battery of claim 1 ,wherein a lower edge of the third ring is on top of an upper edge of the first ring and a lower edge of the first ring is on an upper edge of the second ring.
14. The battery of claim 1 , wherein a gold alloy braze seals the second ring to the first ring, the gold alloy braze being more than 50 wt/% gold.
15. The battery case of claim 14 , wherein the gold alloy braze has a gold content of more than 70 wt %.
16. The battery case of claim 15 , wherein the gold alloy braze includes 96.4% gold, 3.0% nickel, and 0.6% titanium.
17. The battery of claim 1 , wherein a gold alloy braze seals the third ring to the first ring, the gold alloy braze being more than 50 wt % gold.
18. The battery case of claim 17 , wherein the gold alloy braze has a gold content of more than b 70 wt/%.
19. The battery case of claim 17 , wherein the gold alloy braze includes 96.4% gold, 3.0% nickel, and 0.6% titanium.
20. The battery of claim 1 , wherein a weld attaches the third ring to the cylinder.
21. The battery of claim 1 , wherein the ceramic material is selected from the group consisting of: alumina, zirconia, tetragonal zirconia, stabilized-zirconia, partially-stabilized zirconia, yttria-stabilized zirconia, magnesia-stabilized zirconia, acne-stabilized zirconia, calcia-stabilized zirconia, and titania.
22. The battery case of claim 1 , wherein the cylinder and the second ring include the same metal.
23. The battery case of claim 1 , wherein the end cap and the third ring include the same metal.
24. The battery of claim 1 , wherein the second ring includes a material chosen from the group consisting of titanium and alloys thereof.
25. The battery of claim 1 , wherein the third ring includes a material chosen from the group consisting of titanium and alloys thereof.
26. The battery of claim 1 , wherein
the cylinder has a closed end;
the cap includes a feedthrough hole;
the first ring is positioned between the second ring and the third ring such that a lower edge of the third ring is on top of an upper edge of the first ring and a lower edge of the first ring is on an upper edge of the second ring;
the second ring is bonded to the open end of the cylinder such that a lower edge the second ring is on top of an upper edge of the cylinder;
the third ring is bonded to the cap such that the cap is on upper edge of the cylinder; and
a weld attaches the third ring to the cylinder.
27. The battery of claim 26 , wherein
gold alloy brazes seal the second ring to the first ring and the third ring to the first ring the gold alloy brazes being more than 50 wt % gold;
the ceramic material is selected from the group consisting of: alumina, zirconia, tetragonal zirconia, stabilized-zirconia, partially-stabilized zirconia, yttria-stabilized zirconia, magnesia-stabilized zirconia, ceria-stabilized zirconia, calcia-stabilized zirconia, and titania;
the second ring and the third ring each include a material chosen from the group consisting of titanium and alloys thereof.
28. The battery of claim 1 , wherein
gold alloy brazes seal the second ring to the first ring and the third ring to the first ring, the gold alloy brazes being more than 50 wt % gold;
the ceramic material is selected from the group consisting of: alumina, zirconia, tetragonal zirconia, stabilized-zirconia, partially-stabilized zirconia, yttria-stabilized zirconia, magnesia-stabilized zirconia, ceria-stabilized zirconia, calcia-stabilized zirconia, and titania;
the second ring and the third ring each include a material chosen from the group consisting of titanium and alloys thereof.