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 electric circuit board, and the like.
1. An electrochemical cell, which comprises:
a) a ring having a surrounding ring sidewall extending to a ring upper end and a ring lower end;
b) a base having a surrounding base sidewall extending to a base upper end and a base lower end, wherein the ring surrounds the base with the base upper end spaced below the ring upper end;
c) a glass material extending to and sealing with the ring sidewall and the base sidewall;
d) a first electrode supported 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;
e) a separator supported on the first upper electrode side;
f) a second, counter electrode having spaced apart upper and lower second electrode sides with the second lower electrode side supported on the separator and the second upper electrode side spaced below the ring upper end;
g) an electrolyte activating the first and second electrodes; and
h) a plate seated to the ring upper end.
2. The cell of claim 1 wherein the base comprises a recess into which the first electrode is nested.
3. The cell of claim 2 wherein with the first electrode nested in the recess of the base, the upper end of the first electrode is either substantially coplanar with the base upper end or spaced above the base upper end.
4. The cell of claim 1 wherein the plate applies stack pressure to the first and second electrodes.
5. The cell of claim 1 wherein a spring biases between the plate and the second electrode to apply stack pressure to the first and second electrodes.
6. The cell of claim 1 wherein the ring lower end and the base lower end are coplanar.
7. The cell of claim 1 wherein the ring upper end includes a step that receives the plate.
8. The cell of claim 1 including an insulative ring surrounding the first electrode.
9. The cell of claim 1 of either a primary or a secondary chemistry powering an implantable medical device.
10. The cell of claim 1 wherein the first electrode is a cathode of a cathode active material capable of intercalating or intercalating and deintercalating lithium and the second electrode is an anode comprised of lithium or an anode active material capable of intercalating and deintercalating lithium.
11. The cell of claim 1 wherein the base is selected from the group consisting of nickel, titanium, molybdenum, and alloys thereof, and the ring and lid are of stainless steel.