Abstract: A secondary battery includes a cylindrical case; an electrode assembly accommodated in the case and including a first electrode plate, a second electrode plate, and a separator, the electrode assembly being wound such that the first electrode plate is arranged at an outermost side and is in contact with the case; a cap assembly coupled to the case and electrically connected to the second electrode plate; and a first swelling tape attached to an inner surface of the first electrode plate in a state in which the electrode assembly is wound, the first swelling tape having a multi-layer structure. The swelling tape may be applied to a base material finishing portion of the electrode assembly to improve quality distribution of the base material finishing structure due to long-diameter distribution. In addition, a swelling effect may be improved through the multi-layer swelling tape.

Abstract: A technical problem to be solved according to the present disclosure is to provide a secondary battery capable of minimizing contact resistance between a base finish part of an electrode assembly and a can even when a deviation in the winding radius of the electrode assembly occurs, by positioning a swelling tape inside the electrode assembly. To this end, the present disclosure provides a secondary battery including: a cylindrical can, an electrode assembly having a base finish part electrically contacting the cylindrical can; a cap assembly sealing the electrode assembly by blocking the cylindrical can; and a swelling tape positioned inside the base finish part to press the base finish part into the cylindrical can.

Abstract: One embodiment of the present invention relates to a cylindrical secondary battery. The present invention comprises: an electrode assembly comprising a negative electrode plate, a positive electrode plate, and a separator interposed between the negative electrode plate and the positive electrode plate, and having a wound shape in one direction; a metallic finishing tape attached to the outer peripheral surface of the electrode assembly so as to cover at least a portion of the electrode assembly; a cylindrical can having one side opened so as to accommodate the electrode assembly along with an electrolyte; and a cap assembly coupled to the open one side of the can so as to seal the can. According to the present invention, by applying the metallic tape to a winding finishing portion of the electrode assembly, the effect is gained of improving the dispersion of quality of a substrate finishing structure, caused by the dispersion of a major axis.