Rechargeable battery

1. A rechargeable battery, comprising:

an electrode assembly for performing charging and discharging operations;

a case in which the electrode assembly is placed;

a cap plate being coupled to an opening of the case and including a terminal hole having a wide hole opening an external surface of the cap plate and a narrow hole opening an internal surface of the cap plate, the wide and narrow holes of the terminal hole connected to each other;

an electrode terminal electrically coupled to the electrode assembly and including a rivet terminal passing through the wide and narrow holes of the terminal hole of the cap plate and a plate terminal connected to the rivet terminal outside of the cap plate; and

an insulating member for electrically insulating the electrode terminal from the cap plate,

the insulating member including a first insulator surrounding an external circumference of the rivet terminal at the wide hole of the terminal hole and a second insulator between the cap plate and the plate terminal at an external circumference of the first insulator, wherein

the first insulator of the insulating member is partially inserted between the wide hole of the terminal hole and the rivet terminal and is supported by an inner circumferential surface of the wide hole of the terminal hole.

2. The rechargeable battery as claimed in claim 1 , further comprising a gasket between the rivet terminal and the narrow hole of the terminal hole, wherein

the gasket extends between a flange extending from the rivet terminal and an inner surface of the cap plate, and

the gasket and the first insulator contact each other in the terminal hole.

3. The rechargeable battery as claimed in claim 1 , wherein:

the cap plate includes a first protrusion that protrudes toward the plate terminal, and

the first protrusion is inserted into the opening of the case to weld an inner lateral surface of the opening and an outer lateral surface of the first protrusion together.

4. The rechargeable battery as claimed in claim 3 , wherein the cap plate further includes a second protrusion protruding toward the plate terminal to form the wide hole of the terminal hole, and the second protrusion contacting and supporting a circumferential surface of the first insulator.

5. The rechargeable battery as claimed in claim 4 , wherein the plate terminal includes:

a through-hole penetrated by the rivet terminal; and

an expansion groove connected to the through-hole, the expansion groove contacting the first insulator, the expansion groove having a larger diameter than the through-hole.

6. The rechargeable battery as claimed in claim 5 , wherein:

the first insulator is supported at a first side by the external surface of the cap plate and the second protrusion, and

the first insulator is supported at a second side opposite the first side by an inner surface of the plate terminal and the expansion groove.

7. The rechargeable battery as claimed in claim 4 , wherein the second insulator includes:

a plate between the plate terminal and the second protrusion facing each other, the plate including a hole penetrated by the first insulator; and

a protrusion protruding from the plate to partially enclose an external circumferential surface of the plate terminal.

8. The rechargeable battery as claimed in claim 7 , wherein the plate includes a cutting line that that radially extends towards the hole.

9. The rechargeable battery as claimed in claim 4 , wherein:

the plate terminal and the second protrusion face each other, and

the second insulator includes first and second half insulators that are inserted between the plate terminal and the second protrusion in a planar direction of the cap plate to be combined with each other.

10. The rechargeable battery as claimed in claim 1 , wherein:

the first insulator is smaller than the plate terminal, and

the second insulator is larger than the plate terminal.

11. The rechargeable battery as claimed in claim 1 , wherein:

the first insulator includes a synthetic resin material, and

the second insulator includes a rubber material.

12. A rechargeable battery, comprising:

an electrode assembly for performing charging and discharging operations;

a case in which the electrode assembly is placed;

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

an electrode terminal electrically coupled to the electrode assembly and including a rivet terminal passing through a terminal hole of the cap plate and a plate terminal connected to the rivet terminal outside of the cap plate; and

an insulating member for electrically insulating the electrode terminal from the cap plate, the insulating member including a first insulator at an external circumference of the rivet terminal and a second insulator between the cap plate and the plate terminal at an external circumference of the first insulator, the second insulator including first and second half insulators, wherein:

each of the first and second half insulators include:

a half plate including a half groove partially corresponding to an external circumference of the first insulator; and

protrusions protruding from the half plate to partially enclose an external circumferential surface of the plate terminal, and

the protrusion of the first half insulator includes a coupling groove, and the protrusion of the second half insulator includes a coupling protrusion combined with the coupling groove.

13. The rechargeable battery as claimed in claim 12 , wherein the first half insulator and the second half insulator include a synthetic resin material.