Rechargeable battery

1. A rechargeable battery comprising:

an electrode assembly wound with a separator between a first electrode and a second electrode;

a first exterior material including an opening receiving the electrode assembly and facing a bottom side of the electrode assembly;

a second exterior material covering the opening, and combined to the first exterior material to seal an internal side of the first exterior material;

a reinforcing member having greater rigidity than the first exterior material and the second exterior material, disposed between the electrode assembly and the first exterior material, and including a side wall for surrounding a lateral side of the electrode assembly, the side wall having a ring shape; and

a first insulating member between the electrode assembly and the reinforcing member, and insulating the electrode assembly from the reinforcing member.

2. The rechargeable battery of claim 1 , wherein

the reinforcing member further includes an upper wall for surrounding a top side of the electrode assembly and that has a can shape for receiving the electrode assembly.

3. The rechargeable battery of claim 2 , wherein the reinforcing member is made of a metal material, and

wherein the first insulating member surrounds the electrode assembly.

4. The rechargeable battery of claim 3 , further comprising

an electrode tab combined to the electrode assembly, extending from the electrode assembly, and drawn out to an outside of the first exterior material.

5. The rechargeable battery of claim 4 , wherein

the first insulating member includes a through-hole which the electrode tab penetrates, and

the electrode tab is drawn out between the first insulating member and the reinforcing member through the through-hole, and an insulating material is coated on a portion of the electrode tab outside of the first insulating member and contacting the reinforcing member.

6. The rechargeable battery of claim 5 , further comprising

a second insulating member installed on an external side of the first insulating member to close and seal the through-hole.

7. The rechargeable battery of claim 4 , wherein

the first exterior material includes a first edge portion surrounding a circumference of the opening and extending away from the opening,

the second exterior material includes a second edge portion provided on the first edge portion, the first edge portion and the second edge portion together form a terrace portion, and

the electrode tab passes through the terrace portion and is drawn out to an outside of the first exterior material.

8. The rechargeable battery of claim 7 , wherein

the terrace portion is folded to be closely attached to an exterior side of the first exterior material.

9. The rechargeable battery of claim 8 , further comprising

a fixing ring for surrounding the folded terrace portion and fixing the terrace portion to be closely attached to the exterior side of the first exterior material.

10. The rechargeable battery of claim 7 , wherein

the electrode tab is combined to the lateral side of the electrode assembly and is drawn out to the outside.

11. The rechargeable battery of claim 10 , wherein

the electrode tab includes:

a first extension extending to the second exterior material along the lateral side of the electrode assembly;

a second extension extending along the terrace portion from the first extension and drawn out to the outside; and

a bending portion connecting between the first extension and the second extension and that is bent.

12. The rechargeable battery of claim 7 , wherein

the terrace portion includes a draw-out hole through which the electrode tab penetrates and is drawn out, and further includes

a vent sealing portion sealing the draw-out hole and bursting when an internal pressure of the first exterior material increases.

13. The rechargeable battery of claim 1 , wherein the rechargeable battery has a coin shape in which a ratio of diameter to height is equal to or greater than 1.