Rechargeable battery and method of manufacturing the same

1 . A rechargeable battery, comprising;

an electrode assembly including a spirally wound separator, positive electrode, and negative electrode;

a case housing the electrode assembly;

a cap plate including a terminal hole and sealing an opening in one side of the case;

an electrode terminal in the terminal hole of the cap plate and extending inwardly inside the case and outwardly from the case; and

a lead tab having one side connected to the electrode terminal inside the case and another side connected to the electrode assembly, the lead tab including silver (Ag).

2 . The rechargeable battery as claimed in claim 1 , wherein the lead tab includes a body made of a metal and a silvered layer on a surface of the body.

3 . The rechargeable battery as claimed in claim 2 , wherein the lead tab further includes a zincated layer between the body and the silvered layer.

4 . The rechargeable battery as claimed in claim 3 , wherein the zincated layer has a thickness of less than about 1 μm.

5 . The rechargeable battery as claimed in claim 3 , wherein the lead tab further includes a chromated layer on the silvered layer.

6 . The rechargeable battery as claimed in claim 5 , wherein the zincated layer, the silvered layer, and the chromated layer have a total thickness of about 1 μm to about 5 μm.

7 . The rechargeable battery as claimed in claim 2 , wherein the lead tab further includes a chromated layer on the silvered layer.

8 . The rechargeable battery as claimed in claim 2 , wherein the body is made of one of copper (Cu) or aluminum (Al).

9 . A method of manufacturing a rechargeable battery, the method comprising:

supplying an electrode assembly, the electrode assembly including a spirally wound separator, a positive electrode, and a negative electrode;

housing the electrode assembly in a case;

sealing an opening in one side of the case with a cap plate, the cap plate including a terminal hole;

supplying an electrode terminal in the terminal hole of the cap plate, the electrode terminal extending inwardly inside the case and outwardly from the case; and

supplying a lead tab, the lead tab having one side connected to the electrode terminal inside the case and another side connected to the electrode assembly,

wherein supplying the lead tab includes:

degreasing a surface of a lead tab body;

forming a zincated layer on the surface of the degreased lead tab body;

washing a surface of the zincated layer; and

forming a silver layer on the surface of the zincated layer.

10 . The method as claimed in claim 9 , wherein a thickness of the zincated layer is about 1 μm or less.

11 . The method as claimed in claim 9 , wherein degreasing the surface of the lead tab body is performed using a sodium hydroxide solution having a concentration of at least about 0.1 M.

12 . The method as claimed in claim 9 , wherein forming the zincated layer is performed using a solution including about 7 to about 30 g/l of zinc metal, about 10 to about 60 g/l of zinc cyanide, about 10 to about 40 g/l of zinc sodium, and about 30 to about 100 g/l of a 2-3 M sodium hydroxide solution.

13 . The method as claimed in claim 9 , wherein forming the silvered layer is performed using a solution including about 20 to about 50 g/l of silver cyanide, about 30 to about 70 g/l of sodium cyanide, and about 80 to about 150 g/l of potassium cyanide.

14 . The method as claimed in claim 9 , wherein supplying the lead tab further includes forming a chromated layer on a surface of the silvered layer.

15 . The method as claimed in claim 10 , wherein a total thickness of the zincated layer, the silvered layer, and the chromated layer is about 1 μm to about 5 μm.