Secondary battery pouch

A secondary battery pouch comprising:

• a sealing portion formed at an outside of the secondary battery pouch constituting a battery cell and configured to seal an inner space of the secondary battery pouch, the sealing portion is formed by fusion of an upper sheet and a lower sheet,
• wherein the sealing portion comprises:
• a plurality of first fusion portions having a first seal strength and extending continuously along a longitudinal direction of the sealing portion disposed with electrode terminals of the battery cell;
• and
• a plurality of second fusion portions having a second seal strength that is weaker than the first seal strength and extending continuously along the longitudinal direction of the sealing portion disposed with the electrode terminals of the battery cell,
• wherein the first fusion portions and the second fusion portions are configured to provide stepwise sealing release in response to internal gas pressure increase,
• wherein at least one of the second fusion portions is positioned at an innermost side of the sealing portion in contact with the inner space, and
• wherein the first fusion portions and the remaining second fusion portions are arranged alternately toward the outer side of the sealing portion.