Rechargeable battery

1. A battery, comprising:

an electrode assembly including a positive electrode, a negative electrode, and a separator therebetween;

a case housing the electrode assembly;

a cap plate coupled to the case;

a collector plate coupled to the electrode assembly; and

a terminal coupled to the collector plate and passing through the cap plate, wherein:

the terminal includes a terminal protrusion and a bottom protrusion,

the collector plate includes an electrode region coupled to the electrode assembly and a terminal region coupled to the terminal, the terminal region including a combining hole passing therethrough, and

the bottom protrusion of the terminal:

has an interengaging, matching shape relative to a shape of the combining hole,

passes through the combining hole of the collector plate, and

is welded to a lower surface of the collector plate along an edge of the combining hole, wherein the lower surface of the collector plate includes a protruded region that surrounds the combining hole, the combining hole passing through the protruded region;

wherein the combining hole has a length and a width, the length of the combining hole being greater than the width.

2. The battery as claimed in claim 1 , wherein the bottom protrusion is welded to the lower surface of the collector plate in a weld line around a circumference of the combining hole.

3. The battery as claimed in claim 2 , wherein the weld line has a width, the width of the weld line being less than a width of the bottom protrusion.

4. The battery as claimed in claim 1 , wherein the bottom protrusion is welded to the lower surface of the collector plate in a weld line along a length of the bottom protrusion.

5. The battery as claimed in claim 2 , wherein the weld line has a width that is wider than the width of the bottom protrusion, such that the weld line overlaps opposite edges of the combining hole adjacent to the bottom protrusion.

6. The battery as claimed in claim 1 , wherein:

the combining hole has a depth, and

the bottom protrusion has a height sufficient to allow the bottom protrusion to be welded to the lower surface of the collector plate adjacent to the combining hole.

7. The battery as claimed in claim 1 , wherein the terminal further includes an electrically conductive flange between the bottom protrusion and the terminal protrusion.

8. The battery as claimed in claim 1 , wherein the combining hole has a noncircular shape.

9. The battery as claimed in claim 8 , wherein the terminal has a longitudinal axis and the noncircular shape of the combining hole is in a plane transverse to the axis.