Disclosed is a battery including a cathode in which cathode active-material coating layers provided on both surfaces of a cathode collector are longitudinally deviated from each other, and an anode having at least one anode active-material coating layer provided on an anode collector, the cathode and anode being wound to face each other with a separator interposed therebetween. At least one of a winding beginning portion and winding ending portion of the cathode is provided with a cathode uncoated part for installation of a cathode lead. An insulator tape is attached to the boundary of the cathode active-material coating layer at a position where the anode active-material coating layer faces a non-coating part of the cathode not containing the cathode active-material coating layer, achieving enhanced electrical insulation capability and consequential safety of the battery.