SECONDARY BATTERY HAVING IMPROVED ENERGY DENSITY

There is provided a secondary battery including an electrode assembly having a stack structure of an anode/a separation film/a cathode, a pouch type exterior member configured of a lower surface in which a receiving part is formed and an upper surface covering the receiving part, a single electrode assembly or a plurality of electrode assemblies being received in the receiving part, and an electrode terminal formed outwardly of the pouch type exterior member, the secondary battery including: a sealing part formed by bonding edges of the pouch type exterior member, wherein a portion of the sealing part formed on a surface of the pouch type exterior member on which the electrode terminal is not formed outwardly of the exterior member is folded downwardly at an angle of 90 degrees. [0002] According to exemplary embodiment of the present disclosure, the sealing part of a pouch type secondary battery is folded downwardly at an angle of 90 degrees and is in a fixed state, such that a size of the sealing part may be significantly reduced to improve power output per unit volume and further, a pack size may be reduced.