Disclosed is a battery. A battery according to various embodiments is characterized by comprising: a cathode including a cathode tab formed at one end; an anode disposed on one surface of the cathode and including an anode tab formed at one end; an electrode assembly including a first separator disposed between the cathode and the anode and separating the cathode from the anode, and a second separator having one surface disposed on the other surface of the cathode or the anode and including an extended portion extending from the other end of the cathode or the anode; and a pouch surrounding the electrode assembly, wherein the cathode, the anode, the first separator, and the second separator are wound so that the extended portion of the first separator is exposed to the outside, and an exposed surface of the extended portion is formed as an adhesive layer.