Battery cell design and method of its construction
View Patent ↗A compact, robust, multifunctional and highly manufacturable rechargeable battery cell is provided. The cell design dedicates minimal internal volume to inert components of the cell. This is accomplished, in part, by providing multiple functionalities to individual cell components.
1. An electrochemical device, comprising:
an electrode assembly comprising a positive electrode, a negative electrode and an electrolyte;
a cylindrical container housing the electrode assembly and having at least one opening;
an end cap disposed to cover the opening, the end cap defining a centrally-located electrolyte fill hole; and
a plug comprising a plastic seal and a deformable metal insert, the plug sealingly disposed in the centrally-located electrolyte fill hole such that the metal insert is disposed in the plastic seal, wherein at least a portion of the plastic seal and the metal insert passes into the centrally-located fill hole, and wherein the centrally-located electrolyte fill hole provides a feed through inlet for the electrolyte.
2. The electrochemical device of claim 1 , wherein the plug serves as a terminal for connecting the device to an external connection.
3. The electrochemical device of claim 1 , wherein the centrally-located electrolyte fill hole comprises a feed through inlet fittingly disposed within the hole and connected to the interior of the device.
4. The electrochemical device of claim 3 , wherein the feed through inlet comprises:
a rivet having a substantially flat head defining a hole corresponding to the centrally-located electrolyte fill hole and extending over a portion of an external face of the end cap and a hollow stem extending into the interior of the cylindrical container; and
a rivet backing disposed at an internal face of the end cap and engaged with a distal portion of the rivet stem.
5. The electrochemical device of claim 4 , wherein the centrally-located electrolyte fill hole further comprises:
an upper insulating member disposed between the rivet and the end cap and defining a hole corresponding to the centrally-located electrolyte fill hole; and
a lower insulating member disposed between the end cap and the rivet backing.
6. The electrochemical device of claim 4 , wherein the rivet comprises nickel-plated steel.
7. The electrochemical device of claim 4 , wherein the cylindrical container comprises aluminum.
8. The electrochemical device of claim 4 , wherein the end cap comprises aluminum.
9. The electrochemical device of claim 4 , wherein the end cap is at a negative end of the device.
10. The electrochemical device of claim 4 , wherein the end cap is at a positive end of the device.
11. The electrochemical device of claim 1 , wherein the end cap is welded to an open end of the cylindrical container.
12. The electrochemical device of claim 1 , wherein the end cap is welded to an opening of the cylindrical contain.
13. The electrochemical device of claim 1 , wherein the container further comprises a second opening at the opposing end of the cylindrical container and a second end cap is disposed to cover the second opening.
14. The electrochemical device of claim 13 , wherein the second end cap is welded to the second opening of the cylindrical container.
15. The electrochemical device of claim 13 , wherein the second end cap is sealed to the second opening of the cylindrical container with a crimp seal.
16. The electrochemical device of claim 13 , wherein the second end cap comprises aluminum.
17. The electrochemical device of claim 4 , wherein a top portion of the metal insert is configured to engage a flange portion of the plastic seal, wherein the flange portion corresponds to the rivet.
18. The electrochemical device of claim 17 , wherein the metal insert is configured to expand and hold the plastic seal against the rivet disposed within the centrally-located electrolyte fill hole.
19. The electrochemical device of claim 1 , wherein the centrally-located electrolyte fill hole is comprised of an inner diameter and an outer diameter.
20. The electrochemical device of claim 19 , wherein the plastic seal is configured such that a hermetic seal is created in a radial direction when at least a portion of the plastic seal abuts the inner diameter of the centrally-located electrolyte fill hole.
21. The electrochemical device of claim 1 , wherein the centrally-located electrolyte fill hole comprises a rivet having a ledge, and the metal insert is disposed to hold the plastic seal against the ledge.
22. The electrochemical device of claim 21 , wherein the ledge is formed on a stem of the rivet.
23. The electrochemical device of claim 1 , wherein the plastic seal is cup-shaped with an open end and a closed end, the metal insert is inserted into the plastic seal through the open end.
24. The electrochemical device of claim 1 , wherein the plastic seal is a high temperature plastic seal.