Disclosed is a battery including a cathode and an anode wound to face each other with a separator interposed therebetween. Both surfaces of a cathode collector are provided with cathode active-material coating layers so as not to provide a cathode uncoated part at a winding beginning portion of the cathode. The cathode uncoated part for installation of a cathode lead is provided only at a winding ending portion of the cathode. An insulator tape is attached to the boundary of the cathode active-material coating layer facing the anode at the winding ending portion of the cathode. Providing the insulator tape to the boundary of the cathode active-material coating layer at a position where a non-coating part not containing the cathode active-material coating layer and an anode active-material coating layer face each other achieves enhanced electrical insulation capability and consequential safety of the battery.