SECONDARY BATTERY

The present invention relates to a secondary battery in which an electrode assembly and a current collection plate may be easily welded and safety may be improved. As an embodiment, disclosed is a secondary battery comprising: an electrode assembly which is formed by winding a first electrode plate having a first electrode uncoated part, a separator, and a second electrode plate having a second electrode uncoated part, the first electrode uncoated part protruding upwards, and the second electrode uncoated part protruding downwards; and a first current collection plate which is electrically connected to the first electrode uncoated part and has a concave-convex part protruding downwards, wherein the width of the concave-convex part becomes wider from the center of the first current collection plate toward the outer periphery thereof.