Rechargeable battery having desirable safety performance

1. A rechargeable battery comprising a battery case and a battery cap coupled to the battery case, the battery cap comprising:

a conductive cap plate;

a first electrode electrically connected to the cap plate;

a second electrode insulatively coupled to the cap plate via an insulative component, the second electrode being in electrical connection with one end of a conductive plate for securing the second electrode to the conductive can plate; and

a conductive turnover component in electrical connection with the cap plate, the turnover component being initially separated from the conductive plate and capable deforming to contact other end of the conductive plate due to high pressure in the battery case, so as to short-circuit the first electrode and the second electrode.

2. The rechargeable battery according to claim 1 , wherein the turnover component comprises a turnover portion electrically connected with the cap plate and an overcurrent portion electrically connected with the overcurrent portion, the insulative component is formed with a snap ring gasket for matting with the overcurrent portion.

3. The rechargeable battery according to claim 2 , wherein the snap ring gasket is provided with a snap joint portion, the overcurrent portion of the turnover component is provided with a first groove and a second groove below the first groove, the snap joint portion is snapped into the first groove when the turnover component is not turned and snapped into the second groove when the turnover component is turned due to high pressure in the battery case.

4. The rechargeable battery according to claim 3 , wherein the snap joint portion of the snap ring gasket is configured to have a U shape, an S shape or an E shape.

5. The rechargeable battery according to claim 2 , wherein the overcurrent portion and the turnover portion are both made from conductive material.

6. The rechargeable battery according to claim 2 , wherein the overcurrent portion has a column shape and the turnover portion has a ring shape, inner edge of the turnover portion is recessed downwardly to form an elastic structure, and outer edge of the turnover portion is electrically connected with the cap plate.

7. The rechargeable battery according to claim 6 , wherein outer surface of the turnover component is provided with a treatment layer made from a group consisting of brass, bronze, nickel, silver and gold.

8. The rechargeable battery according to claim 6 , wherein the distance between the overcurrent portion of the turnover component and the conductive plate is 0.5˜1.0 mm when the overcurrent portion is not turned, and the overcurrent portion of the turnover component is in planar contact with the conductive plate when the overcurrent portion is turned.

9. The rechargeable battery according to claim 6 , wherein the thickness of the turnover portion is 0.1˜0.4 times of that of the overcurrent portion.

10. The rechargeable battery according to claim 9 , wherein the overcurrent portion has a thickness of about 0.8˜1.5 mm and the turnover portion has a thickness of about 0.1˜0.3 mm.

11. The rechargeable battery according to claim 6 , wherein the overcurrent portion has a thickness no less than that of the conductive plate and larger than that of the turnover portion.