Secondary battery and battery pack including the same

1. A secondary battery, comprising:

an electrode assembly having a first electrode plate, a separator, and a second electrode plate;

a collecting plate electrically connected to the electrode assembly;

a case configured to accommodate the electrode assembly and the collecting plate;

a cap plate configured to seal the case;

an electrode terminal part disposed through the cap plate and electrically connected to the collecting plate, the electrode terminal part including a first electrode terminal, a second electrode terminal, and a third electrode terminal, wherein the first and second electrode terminals include screw threads on outer surfaces thereof, the second electrode terminal extending through the cap plate into the case; and

a connection member between the second electrode terminal and the cap plate, wherein the first, second, and third electrode terminals are integral such that the first, second, and third electrode terminals are collectively a single piece, and

wherein the connection member is coupled to the second electrode terminal through the screw threads and a lower end thereof is coupled to the collecting plate through riveting.

2. The secondary battery as claimed in claim 1 , further comprising an upper insulation member on an upper side of the cap plate to be external to the case, the upper insulation member contacting a screw thread of the second electrode terminal.

3. The secondary battery as claimed in claim 2 , wherein the third electrode terminal is wider than the second electrode terminal, the third electrode terminal being between the upper insulation member and the first electrode terminal.

4. The secondary battery as claimed in claim 3 , wherein the third electrode terminal includes a bent part, the bent part being inserted into and affixed to the upper insulation member.

5. The secondary battery as claimed in claim 3 , wherein the third electrode terminal is between the first and second electrode terminals, the second electrode terminal being between the third electrode terminal and the electrode assembly.

6. The secondary battery as claimed in claim 3 , further comprising an auxiliary seal member between the third electrode terminal and the upper insulation member.

7. The secondary battery as claimed in claim 2 , further comprising an upper seal member between the upper insulation member and the cap plate.

8. The secondary battery as claimed in claim 1 , further comprising a lower insulation member under the cap plate around the connection member.

9. The secondary battery as claimed in claim 8 , further comprising a lower seal member between the connection member and the cap plate.

10. The secondary battery as claimed in claim 1 , wherein the third electrode terminal is between the first and second electrode terminals and is wider than each of the first and second electrode terminals, the second electrode terminal directly contacting the collecting plate and including a screw thread.

11. The secondary battery as claimed in claim 10 , further comprising an upper insulation member between an outer surface of the cap plate and the third electrode terminal, the upper insulation member contacting the screw thread of the second electrode terminal.

12. A battery pack, comprising:

a plurality of secondary batteries, each secondary battery including:

an electrode assembly having a first electrode plate, a separator, and a second electrode plate,

a collecting plate electrically connected to the electrode assembly,

a case configured to accommodate the electrode assembly and the collecting plate,

a cap plate configured to seal the case,

an electrode terminal part disposed through the cap plate and electrically connected to the collecting plate, the electrode terminal part including a first electrode terminal, a second electrode terminal, and a third electrode terminal, wherein the first and second electrode terminals include screw threads on outer surfaces thereof, the second electrode terminal extending through the cap plate into the case, and the first, second, and third electrode terminals are integral such that the first, second, and third electrode terminals are collectively a single piece; and

a connection member between the second electrode terminal and the cap plate, the connection member being coupled to the second electrode terminal through the screw threads, and a lower end of the connection member being coupled to the collecting plate through riveting;

a bus bar with a penetration hole, the electrode terminal part extending through the penetration hole; and

a nut coupled to the electrode terminal part to fix the bus bar to the electrode terminal part.

13. The battery pack as claimed in claim 12 , wherein the bus bar is coupled to the first electrode terminal, the bus bar being positioned on the third electrode terminal.

14. The battery pack as claimed in claim 12 , wherein the nut is coupled to the first electrode terminal.