<p>PURPOSE: A secondary battery is provided to improve heat dissipation of a battery by widening the area of a can contacting an electrode assembly by forming a can in which at least two accommodation spaces are formed between separated spaces. CONSTITUTION: A secondary battery(100) comprises: a can(110) in which at least two accommodation spaces are formed between separated spaces(112); an electrode assembly(120) which is built in the accommodation spaces; a current collector(130) electrically connected to the electrode assembly; and a cap plate(140) which is coupled with the upper side of the can and seals the can.</p>
