Secondary battery

1. A secondary battery comprising:

an electrode assembly comprising a first electrode, a second electrode, and a separator between the first and second electrodes;

a first collecting part electrically connected to the first electrode;

a second collecting part electrically connected to the second electrode;

a case configured to receive the electrode assembly;

a cap assembly comprising a cap plate configured to seal an opening of the case; and

an auxiliary connection part electrically connected between the second collecting part and the cap plate,

wherein the second collecting part comprises:

at least two fuse parts;

a first extension part; and

a second extension part connected to the second electrode, and

wherein a first end of the auxiliary connection part is connected to a fixing part of the second collecting part between first and second fuse parts of the at least two fuse parts, and a second end of the auxiliary connection part is connected to a bottom surface of the cap plate or an inner side of the case.

2. The secondary battery as claimed in claim 1 ,

wherein the first and second fuse parts are arranged on the second collecting part and spaced apart from each other, and

wherein the first and second fuse parts include penetration holes formed through the second collecting part, respectively.

3. A secondary battery comprising:

an electrode assembly comprising a first electrode, a second electrode, and a separator between the first and second electrodes;

a first collecting part electrically connected to the first electrode;

a second collecting part electrically connected to the second electrode;

a case configured to receive the electrode assembly;

a cap assembly comprising a cap plate configured to seal an opening of the case; and

an auxiliary connection part electrically connected between the second collecting part and the cap plate,

wherein the second collecting art comprises:

at least two fuse parts;

a first extension part; and

a second extension part connected to the second electrode,

wherein the at least two fuse parts comprise first and second fuse parts arranged on the second collecting part and spaced apart from each other,

wherein the first and second fuse parts include penetration holes formed through the second collecting part, respectively,

wherein the first extension part is fixed to and electrically connected to a bottom surface of the cap plate, and

wherein the first and second fuse parts are arranged on the second extension part extending at an angle from the first extension part.

4. The secondary battery as claimed in claim 2 ,

wherein the second extension part comprises the fixing part between the first fuse part and the second fuse part, and

wherein the second end of the auxiliary connection part is connected to the bottom surface of the cap plate.

5. A secondary battery comprising:

an electrode assembly comprising a first electrode, a second electrode, and a separator between the first and second electrodes;

a first collecting part electrically connected to the first electrode;

a second collecting part electrically connected to the second electrode;

a case configured to receive the electrode assembly;

a cap assembly comprising a cap plate configured to seal an opening of the case; and

an auxiliary connection part electrically connected between the second collecting part and the cap plate,

wherein the second collectin part comprises:

at least two fuse parts;

a first extension part; and

a second extension part connected to the second electrode,

wherein the at least two fuse parts comprise first and second fuse parts arranged on the second collecting part and spaced apart from each other,

wherein the first and second fuse parts include penetration holes formed through the second collecting part, respectively, and

wherein the penetration hole of the first fuse part is larger than the penetration hole of the second fuse part.

6. The secondary battery as claimed in claim 2 ,

wherein the second extension part comprises the fixing part between the first fuse part and the second fuse part, and

wherein the second end of the auxiliary connection part is connected to the inner side of the case.

7. A secondary battery comprising:

an electrode assembly comprising a first electrode, a second electrode, and a separator between the first and second electrodes;

a first collecting part electrically connected to the first electrode;

a second collecting part electrically connected to the second electrode;

a case configured to receive the electrode assembly;

a cap assembly comprising a cap plate configured to seal an opening of the case; and

an auxiliary connection part electrically connected between the second collecting part and the cap plate,

wherein the second collecting part comprises:

at least two fuse parts;

a first extension part; and

a second extension part connected to the second electrode,

wherein the first collecting part comprises a first electrode terminal inserted through a first terminal hole of the cap plate,

wherein the first electrode terminal comprises a short-circuit plate,

wherein the cap plate has a short-circuit hole at a location corresponding to the short-circuit plate, and

wherein the cap assembly further comprises a short-circuit member covering the short-circuit hole.

8. The secondary battery as claimed in claim 7 , wherein the short-circuit member comprises a reversible plate comprising:

an edge part fixed to the cap plate; and

a convex part extending from the edge part into the short-circuit hole.

9. The secondary battery as claimed in claim 8 , wherein the convex part is configured to contact the short-circuit plate when an inside pressure of the secondary battery exceeds a reference pressure.

10. The secondary battery as claimed in claim 9 , wherein when the convex part contacts the short-circuit plate, the first and second fuse parts are configured to disconnect at regions between edges of the penetration holes of the respective first and second fuse parts and edges of the second extension part to interrupt a current.

11. A secondary battery comprising:

an electrode assembly comprising a first electrode, a second electrode, and a separator between the first and second electrodes;

a first collecting part electrically connected to the first electrode;

a second collecting part electrically connected to the second electrode;

a case configured to receive the electrode assembly;

a case assembly comprising a cap plate configured to seal an opening of the case; and

an auxiliary connection part electrically connected between the second collecting part and the cap plate,

wherein the second collecting part comprises:

at least two fuse parts;

a first extension part; and

a second extension part connected to the second electrode, and

wherein the first and second collecting parts comprise first and second electrode terminals protruding outward from the cap plate, respectively.

12. The secondary battery as claimed in claim 11 , wherein the at least two fuse parts comprise:

a first fuse part arranged on the first extension part; and

a second fuse part arranged on the second extension part extending at an angle from the first extension part.

13. The secondary battery as claimed in claim 11 ,

wherein the first and second electrode terminals are inserted through terminal holes formed in the cap plate and protrude outward from the cap plate,

wherein the first electrode terminal comprises a short-circuit plate,

wherein the cap plate has a short-circuit hole at a location corresponding to the short-circuit plate, and

wherein the cap assembly further comprises a short-circuit member covering the short-circuit hole.

14. The secondary battery as claimed in claim 13 , wherein the short-circuit member comprises a reversible plate comprising:

an edge part fixed to the cap plate; and

a convex part extending from the edge part into the short-circuit hole.

15. The secondary battery as claimed in claim 14 , wherein the convex part is configured to contact the short-circuit plate when an inside pressure of the secondary battery exceeds a reference pressure.

16. The secondary battery as claimed in claim 15 , wherein when the convex part contacts the short-circuit plate, the first and second fuse parts are configured to disconnect at regions between edges of penetration holes of the respective first and second fuse parts and edges of the second extension part to interrupt a current.

17. The secondary battery as claimed in claim 11 , further comprising insulation members between the cap plate and the first and second electrode terminals.