Method for providing a hermetically sealed coin cell
View Patent ↗A hermetically sealed coin cell is described. The coin cell has the opposite polarity terminals isolated from one another by a glass-to-metal seal. Glassing a conductive disc inside a ring of greater diameter and height forms this seal. The height of the ring is equivalent to the desired height of the cell. The disc acts as one cell terminal, which can be positive or negative, and the ring serves as the other terminal. In plan view, both terminals are on the same side of the cell. This allows for easy mounting and connection to an electronic circuit board, and the like.
1. A method for providing an electrochemical battery, comprising the steps of:
a) providing a ring having a surrounding ring sidewall extending to a ring upper end and a ring lower end;
b) providing a base having a surrounding base sidewall extending to a base upper end and a base lower end;
c) positioning the base inside the ring surrounding the base with the base upper end spaced below the ring upper end;
d) sealing the base to the ring with a glass material;
e) positioning a first electrode on the base upper end, the first electrode having spaced apart upper and lower first electrode sides with the first lower electrode side proximate the base upper end and the first upper electrode side spaced below the ring upper end;
f) supporting a separator on the first upper electrode side;
g) positioning a second, counter electrode on the separator, the second electrode having spaced apart upper and lower second electrode sides with the second upper electrode side spaced below the ring upper end;
h) activating the first and second electrodes with an electrolyte; and
i) sealing a plate to the ring upper end.
2. The method of claim 1 including providing the base having a recess and nesting the first electrode into the recess.
3. The method of claim 2 including providing the upper end of the first electrode being either substantially coplanar with the base upper end or being spaced above the base upper end with the first electrode nested in the base recess.
4. The method of claim 1 including having the plate applying a stack pressure to the first and second electrodes.
5. The method of claim 1 including applying stack pressure to the first and second electrodes with a spring biasing between the plate and the second electrode.
6. The method of claim 1 including providing the ring lower end and the base lower end being coplanar.
7. The method of claim 1 including providing the ring upper end comprising a step receiving the plate welded to the ring.
8. The method of claim 1 including surrounding the first electrode with an insulative ring.
9. The method of claim 1 including providing the cell of either a primary or a secondary chemistry powering an implantable medical device.
10. The method of claim 1 including providing the first electrode as a cathode of a cathode active material capable of intercalating or intercalating and deintercalating lithium and the second electrode as an anode comprised of lithium or an anode active material capable of intercalating and deintercalating lithium.
11. The method of claim 1 including providing a first coefficient of thermal expansion of the ring being greater than a second coefficient of thermal expansion of the glass, which, in turn, is greater than a third coefficient of thermal expansion of the base.
12. The method of claim 1 including selecting the base from the group consisting of nickel, titanium, molybdenum, and alloys thereof, and proving the ring and lid being of stainless steel.