Rechargeable battery including an extensible member

1. A rechargeable battery comprising:

a case;

a first electrode coupled to the case;

a second electrode coupled to the case, the second electrode having a portion extending outside of the case;

a first short bar electrically coupled to the first electrode;

a second short bar electrically coupled to said portion of the second electrode; and

an extensible member extending from the case, the extensible member being extensible from a first position in which a conductive portion on the extensible member is spaced apart from the first short bar and the second short bar by a gap to an extended position in which the conductive portion contacts the first short bar and the second short bar,

wherein the extensible member is configured to couple the second short bar electrically to the first short bar in the extended position in response to an overcharging condition of the rechargeable battery, thereby short-circuiting the first and second electrodes via the first and second short bars, wherein the extensible member comprises an electrical conductor, and wherein the extensible member is electrically coupled to a cap plate on the case.

2. The rechargeable battery as claimed in claim 1 , wherein the extensible member is configured to extend toward the first and second short bars when an internal pressure of the case is above a set value.

3. The rechargeable battery as claimed in claim 1 , wherein the extensible member and the first and second short bars are configured to remain electrically coupled to each other in response to the overcharging condition.

4. The rechargeable battery as claimed in claim 1 , wherein at least one of the extensible member or the first and second short bars is configured to melt when the extensible member and the first and second short bars conduct an electrical current in response to the overcharging condition.

5. The rechargeable battery as claimed in claim 1 , wherein the second short bar is welded and/or screwed to said portion of the second electrode.

6. The rechargeable battery as claimed in claim 1 , further comprising:

a spring having two end portions with one of the end portions coupled to the case and the other one of the end portions coupled to a side of the extensible member acing the short bar,

wherein the spring is configured to apply a pressure on the extensible member in a direction toward the case and away from the short bar.

7. The rechargeable battery as claimed in claim 6 , wherein the spring comprises two springs positioned diametrically on the side of the extensible member facing the short bar.

8. The rechargeable battery as claimed in claim 6 , wherein the pressure applied on the extensible member by the spring is less than an internal pressure of the case applied on the extensible member when the rechargeable battery is in the overcharging condition.

9. A rechargeable battery comprising:

a case;

a first electrode coupled to the case;

a second electrode coupled to the case, the second electrode having a portion extending outside of the case;

a third electrode coupled to the case, the third electrode having a portion extending outside of the case;

a first short bar electrically coupled to said portion of the second electrode;

a second short bar electrically coupled to said portion of the third electrode, the first short bar being adjacent to the second short bar with a gap therebetween; and

an extensible member extending from the case, the extensible member located below the first and second short bars with a gap therebetween,

wherein the extensible member is configured to couple the first short bar electrically to the second short bar in response to an overcharging condition of the rechargeable battery, thereby short-circuiting the first and second electrodes via the first and second short bars.

10. The rechargeable battery as claimed in claim 9 , wherein the extensible member is electrically coupled to a cap plate on the case.

11. The rechargeable battery as claimed in claim 9 , wherein the extensible member is configured to extend toward the first and second short bars when an internal pressure of the case is above a set value.

12. The rechargeable battery as claimed in claim 9 , wherein the second short bar is between the first short bar and the extensible member.

13. The rechargeable battery as claimed in claim 9 , wherein the first and second short bars are at substantially a same distance from the extensible member.

14. The rechargeable battery as claimed in claim 13 , wherein the extensible member comprises an electrical conductor.

15. The rechargeable battery as claimed in claim 13 , further comprising a conduction plate on the extensible member,

wherein the conduction plate is configured to electrically couple the first and second short bars together in response to the overcharging condition.

16. The rechargeable battery as claimed in claim 9 , wherein the first and second short bars are configured to remain electrically coupled to each other in response to the overcharging condition.

17. The rechargeable battery as claimed in claim 9 , wherein at least one of the first short bar or the second short bar is configured to melt when the first short bar and the second short bar conduct an electrical current in response to the overcharging condition.

18. The rechargeable battery as claimed in claim 9 , wherein the first short bar is welded and/or screwed to said portion of the second electrode.