SECONDARY BATTERY

A secondary battery includes: an electrode assembly including a first electrode tab and a second electrode tab; a first current collector plate electrically connected to the first electrode tab; a case in which the first current collector plate and the electrode assembly are accommodated; a cap plate sealing an upper end of the case and including a coupling protrusion protruding downward; and an insulating member coupled to and fixed to the coupling protrusion at a lower portion of the cap plate, and the first current collector plate is coupled to a coupling hook located under the insulating member to be fixed.