Method of sealing pouch-type battery case and pouch-type secondary battery

A pouch-type secondary battery comprising:

• a pouch-type battery case including a first case unit extending along a first direction and a second direction intersecting the first direction, the first direction having a first side and a second side opposite to the first side and the second direction having a third side and a fourth side opposite to the third side, and a second case unit with an end portion in the first direction connected to an end portion of the first side of the first case unit being bent with respect to the first case unit to face the first case unit in a third direction intersecting the first direction and the second direction to cover the first case unit;
• and
• an electrode assembly accommodated between the first case unit and the second case unit,
• wherein each of the first case unit and the second case unit include an accommodation portion in contact with or facing the electrode assembly and an extension that extends outward from the accommodation portion and at least partially surrounding the accommodation portion, the extension configured to be bondable, the electrode assembly being disposed between the accommodation portions of the first case unit and the second case unit, the extensions of the first case unit and the second case unit include first sealing regions bonded to face each other in a pre-sealing operation and second sealing regions bonded to face each other in a main sealing operation after the pre-sealing operation, the first sealing regions include first regions or second regions of the extensions of the first case unit and the second case unit, the first regions are adjacent to an end portion of the third side of the electrode assembly at an end portion of the second side of the electrode assembly and face each other and the second regions are adjacent to an end portion of the fourth side of the electrode assembly at an end portion of the second side of the electrode assembly and face each other, and the second sealing regions include seventh regions or eighth regions of the extensions of the first case unit and the second case unit, the seventh regions positioned at the third side of the electrode assembly and facing each other and the eighth regions positioned at the fourth side of the electrode assembly and facing each other
• wherein lengths of the first regions and the second regions in the first direction are each smaller than a length of the electrode assembly in the first direction, and wherein the seventh regions have a greater total length in the first direction than the first regions, and the eighth regions have a greater total length in the first direction than the second regions.