Rechargeable battery

1. A rechargeable battery comprising:

a case accommodating an electrode assembly;

a cap plate closing and sealing an opening of the case;

an electrode terminal comprising a rivet terminal and a plate terminal, the rivet terminal being coupled to the electrode assembly and extending through a terminal opening in the cap plate, and the plate terminal being at an upper surface of the cap plate and coupled to the rivet terminal, the upper surface of the cap plate facing away from the case; and

a first insulator and a second insulator electrically insulating the electrode terminal from the cap plate, the first insulator and the second insulator being separate from and interlocked with each other, the first insulator being between the cap plate and the plate terminal at an outer periphery of the rivet terminal, and the second insulator being coupled to the first insulator at an outer periphery thereof and being between the cap plate and the plate terminal.

2. The rechargeable battery of claim 1 , wherein the first insulator accommodates the rivet terminal via an opening corresponding to the terminal opening and comprises a first hook at one side thereof, and

wherein the second insulator comprises a second hook, and the second hook is coupled to the first hook.

3. The rechargeable battery of claim 2 , wherein the second insulator surrounds the outer periphery of the first insulator, and

wherein the second insulator comprises a third hook combined to a side of the first insulator opposite to a side thereof at which the first hook is arranged.

4. The rechargeable battery of claim 3 , wherein the second insulator comprises:

an insertion plate having the same thickness as the first insulator and arranged between the cap plate and the plate terminal; and

a protrusion rim protruding along an outer edge of the insertion plate to surround a periphery of the plate terminal.

5. The rechargeable battery of claim 4 , wherein the protrusion rim extends along each side of second insulator except the side thereof at which the third hook is arranged to surround the periphery of the plate terminal.

6. The rechargeable battery of claim 1 , wherein the first insulator comprises a first hook and is coupled to the electrode terminal in a stacking direction of the cap plate, and

wherein the second insulator is inserted to be between the cap plate and the plate terminal in a lateral direction perpendicular to the stacking direction and is coupled to the first insulator by the first hook.

7. The rechargeable battery of claim 6 , wherein the second insulator comprises a second hook and a third hook, the second hook being at an inner side of the second insulator,

wherein the first hook of the first insulator is coupled to the second hook, and

wherein the third hook is coupled to the first insulator at an opposite side of the first insulator with respect to the first hook.

8. The rechargeable battery of claim 1 , wherein the first insulator has long sides corresponding to a length direction of the cap plate and short sides corresponding to a width direction of the cap plate, and

wherein the first insulator comprises a first hook at one of the short sides thereof.

9. The rechargeable battery of claim 8 , wherein the second insulator has long and short sides respectively corresponding to the long and short sides of the first insulator, and

wherein the second insulator comprises a second hook at one of the short sides thereof, and the second hook is coupled to the first hook.

10. The rechargeable battery of claim 9 , wherein the second insulator further comprises:

an insertion plate having the same thickness as the first insulator and arranged between the cap plate and the plate terminal; and

a protrusion rim protruding along an outer edge of the insertion plate to surround a periphery of the plate terminal,

wherein the protrusion rim is at the long sides of the second insulator and one of the short sides nearest to the second hook.

11. The rechargeable battery of claim 1 , wherein the first insulator has a width that is less than a width of the cap plate, and

wherein the second insulator has a width substantially the same as the width of the cap plate.