SECONDARY BATTERY AND METHOD FOR MANUFACTURING THE SAME

A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case accommodating the electrode assembly, and including an open first side-surface and an open second side-surface that are opposite to each other; and a vent at a surface of the case. A thickness of the vent is smaller than a thickness of a portion of the surface of the case without the vent.