Patent ID: 8758927

Claim:
A secondary battery, comprising: a can having at least two receiving spaces with a separation space therebetween such that each receiving space is separated from every other receiving space by the separation space; an electrode assembly received in the receiving spaces of the can, wherein: the electrode assembly includes a separator disposed between a positive electrode plate and a negative electrode plate, the separator, positive electrode plate, and negative electrode plate are spirally wound; and the electrode assembly has an oval-shaped cross-section with a height along a long axis of the oval shape; a collector electrically connected to the electrode assembly; and a cap plate coupled to an upper portion of the can to seal the can, wherein the can includes: long sidewalls having a length, the long sidewalls being spaced apart from and facing each other, short sidewalls connected to the long sidewalls, the short sidewalls having a length less than the length of the long sidewalls and being spaced from and facing each other, and separation sidewalls disposed at central portions of the short sidewalls, the separation sidewalls being parallel to the long sidewalls, the separation sidewalls being flat, and the separation sidewalls facing each other, wherein the separation sidewalls are parallel to the long axis of the oval-shaped cross-section of the electrode assembly, and a height of the separation sidewalls is less than or equal to the height of the oval-shaped cross-section of the electrode assembly.