New patent application published for: Secondary Battery

Secondary Battery

Claims

1. A secondary battery comprising: an electrode assembly comprising at least one electrode tab extending outwardly therefrom; a current collector electrically coupled to the at least one electrode tab; and a casing receiving the electrode assembly and the current collector therein, wherein the current collector comprises: a current collecting unit and a pole unit coupled together, wherein the current collecting unit comprises a plate having an opening therein, wherein the pole unit comprises: a current collecting protrusion; and a support portion coupled to an end of the current collecting protrusion, wherein the current collecting protrusion extends away from the support portion along a central axis of the pole unit, wherein a cross-sectional area of the support portion is greater than a cross-sectional area of the current collecting protrusion along a plane perpendicular to the central axis, and wherein the support portion is at least partially accommodated in the opening and secured within the opening by a welding region disposed between a periphery of the support portion and a perimeter of the opening.
2. The secondary battery according to claim 1, wherein the welding region is disposed along an entirety of the perimeter of the opening.
3. The secondary battery according to claim 1, wherein the opening defines a through hole extending through the current collecting unit.
4. The secondary battery according to claim 3, wherein the opening communicates with a recessed region defined in a lower surface of the current collecting unit, the recessed region having a larger cross-sectional area along a plane perpendicular to the central axis than the opening.
5. The secondary battery according to claim 4, wherein the support portion is at least partially accommodated within the recessed region.
6. The secondary battery according to claim 4, wherein the support portion is fully accommodated within the recessed region.
7. The secondary battery according to claim 4, wherein a depth of the recessed region ranges from 30% to 50% of a height of the plate of the current collecting unit.
8. The secondary battery according to claim 1, wherein the opening defines a blind hole terminating within the current collecting unit.
9. The secondary battery according to claim 1, wherein the current collector further comprises a stopper adjacent to the opening, the stopper having an upper surface spaced above an upper surface of the plate along an axial direction parallel to the central axis of the pole unit.
10. The secondary battery according to claim 9, wherein the stopper is a portion of the current collector unit.
11. The secondary battery according to claim 10, wherein the upper surface of the stopper is provided by an upper surface of a portion of the current collecting unit that circumscribes the opening.
12. The secondary battery according to claim 10, wherein an upper surface of the stopper is flush with an upper surface of the support portion.
13. The secondary battery according to claim 10, wherein the opening defines a through hole extending through the current collecting unit, the opening communicating with a recessed region defined in a lower surface of the current collecting unit, the recessed region having a larger cross-sectional area along a plane perpendicular to the central axis than the opening, and wherein a cross-sectional area of the recessed region is smaller than a cross-sectional area of the stopper.
14. The secondary battery according to claim 13, wherein a depth of the recessed region is equal to or greater than a height of an end of the current collecting unit.
15. The secondary battery according to claim 13, wherein a lower surface of the support portion is positioned above the lower surface of the current collecting unit.
16. The secondary battery according to claim 9 wherein the stopper is a portion of the pole unit.
17. The secondary battery according to claim 16, wherein the upper surface of the stopper is provided by an upper surface of the support portion.
18. The secondary battery according to claim 16, wherein the stopper is disposed between the current collecting protrusion and the support portion, wherein a cross-sectional area of the stopper is greater than a cross-sectional area of the protrusion portion and different than the cross-sectional area of the support portion along a plane perpendicular to the central axis.
19. The secondary battery according to claim 1, wherein a lower surface of the current collecting unit is flush with a lower surface of the support portion.
20. The secondary battery according to claim 1, wherein a nickel plating layer is formed on an upper end of the current collecting protrusion.
21. The secondary battery according to claim 1, wherein the current collecting unit further comprises: a first current collecting portion; a second current collecting portion; and a connection portion, wherein the first current collecting portion is coupled to a plurality of first electrode tabs, wherein the second current collecting portion is coupled to a plurality of second electrode tabs, and wherein the connection portion is connected to the first current collecting portion and includes the opening.
22. The secondary battery according to claim 21, wherein the plurality of first electrode tabs are bent toward an upper surface of the first current collecting portion, and the plurality of second electrode tabs are bent toward an upper surface of the second current collecting portion in a direction opposite to a direction in which the plurality of first electrode tabs are bent, and wherein a separation distance between the plurality of first electrode tabs and the plurality of second electrode tabs is 5% to 15% of a length of the current collector.