A cylindrical battery cell including a first electrode terminal and a second electrode terminal having different polarities: an electrode assembly in which a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode are wound; a battery case configured to include the electrode assembly therein in a state of being impregnated with an electrolytic solution; a cap assembly mounted to a top end of the battery case; and a connection cap including a cap housing loaded on the battery case and the cap assembly and having an insulating material, and a first connection plate and a second connection plate placed on the cap housing and electrically connected to the first electrode terminal and the second electrode terminal, respectively.