Electrode assembly and secondary battery comprising the same

1 . An electrode assembly, comprising:

an anode plate having an anode coating layer formed on an anode current collector plate, the anode plate having a rectangular shape;

a cathode plate having a cathode coating layer formed on a cathode current collector plate; and

a separator interposed between the cathode plate and the anode plate, the electrode assembly being formed by winding a stack of the anode plate, the separator, and the cathode plate into a wound electrode assembly,

wherein the cathode plate comprises:

a side extending along a lengthwise direction;

an opposite side opposite to the side, the opposite side extending along the lengthwise direction;

a leading side directly connecting the side and the opposite side and located at a center winding portion of the wound electrode assembly, an entirety of the leading side being slanted in a same direction to have an acute angle or obtuse angle with respect to the side, and the cathode coating layer extending to the leading side to contact the leading side; and

a terminating side connecting the side and the opposite side and located, as a side opposite to the leading side, on an outermost side of the wound electrode assembly.

2 . The electrode assembly of claim 1 , wherein the leading side is located in a leading-end region, the cathode plate is a right-angled triangle in the leading-end region, and the leading side is an oblique side of the right-angled triangle.

3 . The electrode assembly of claim 2 , wherein the leading-end region is wound by any one of ¼ to 1 turn when the electrode assembly is wound in a cylindrical shape.

4 . The electrode assembly of claim 1 , wherein the terminating side is parallel to the leading side, so that the cathode plate is a parallelogram plate.

5 . The electrode assembly of claim 1 , wherein the anode plate is a rectangular plate and has a side and an opposite side, extending along the lengthwise direction and parallel to the side of the cathode plate, a leading side connecting the side of the anode plate and the opposite side of the anode plate and located at the center winding portion of the wound electrode assembly, and a terminating side connecting the side and the opposite side of the anode plate and located, as a side opposite to the leading side of the anode plate, on the outermost side of the wound electrode assembly.

6 . The electrode assembly of claim 5 , wherein the leading side of the anode plate extends longer toward the center winding portion along the longitudinal direction than the leading side of the cathode plate.

7 . A secondary battery, comprising:

the wound electrode assembly as claimed in claim 1 ;

a case having an internal space, wherein the wound electrode assembly and an electrolyte are accommodated in the inner space; and

a cap plate that is coupled to an upper portion of the case to seal the case.

8 . The electrode assembly of claim 1 , wherein an edge of the separator extends beyond the leading side of the cathode plate in the center winding portion of the wound electrode assembly.

9 . The electrode assembly of claim 1 , further comprising a cathode tab protruding perpendicularly from the cathode current collector, the cathode tab being spaced apart from the leading side along a longitudinal direction of the cathode current collector, and the cathode tab being separated from the leading side by a portion of the cathode coating layer.