SECONDARY BATTERY

A secondary battery according to an exemplary embodiment of the present invention includes: an electrode assembly; and a pouch case in which the electrode assembly is embedded, in which the pouch case includes a first case part formed with a first accommodating part in which a part of the electrode assembly is embedded, and a second case part formed with a second accommodating part in which the remaining part of the electrode assembly is accommodated, the first case part and the second case part are in contact with each other in an edge portion surrounding the first and second accommodating parts and are sealed by a sealing part formed in a band shape on at least a part of the edge portion, the sealing part includes a first sealing part having a first width and a second sealing part having a second width smaller than the first width, and a central portion of the second sealing part in a longitudinal direction coincides with a central portion of a long side of the electrode assembly.