Pouch bag for secondary battery and pouch type secondary battery comprising same
A pouch bag that can be opened and closed during the degassing process and a pouch type secondary battery comprising the same, which has an economical effect because the pouch bag surplus portion to be discarded after the degassing process does not occur. This results in a reduction of waste material in the manufacturing process.
1 . A pouch bag for a secondary battery, comprising:
an electrode assembly accommodating portion;
a sealing portion; and
an opening and closing portion configured to be repeatedly opened and closed with respect to the sealing portion,
wherein the pouch bag comprises:
a first pouch film and a second pouch film, the first pouch film including a first metal layer and a first inner resin layer positioned on a first surface of the first metal layer, and the second pouch film including a second metal layer and a second inner resin layer positioned on a first surface of the second metal layer; and
the opening and closing portion including a protrusion portion provided on the first inner resin layer of the first pouch film sealed together with the second pouch film, and a protrusion fixing portion provided on the second inner resin layer of the second pouch film,
wherein the protrusion portion has a protrusion protruding from a surface of the first inner resin layer, and the protrusion fixing portion includes a groove, the groove being recessed in a surface of the second inner resin layer within which the protrusion portion is configured to be disposed,
wherein the first inner resin layer of the first pouch film includes a first planar surface extending along and facing the second inner resin layer,
wherein the protrusion is entirely protruded from the first planar surface,
wherein the second inner resin layer of the second pouch film includes a second planar surface extending along and facing the first inner resin layer, and
wherein the groove is entirely recessed in the second planar surface.
2 . The pouch bag for the secondary battery according to claim 1 , wherein the sealing portion is positioned in a ring form configured to surround a perimeter of the electrode assembly accommodating portion, and the opening and closing portion is positioned on a left sealing portion or a right sealing portion in an axial dimension of the pouch bag, the axial dimension being parallel to an axis along which the electrode terminal extends when the electrode assembly is accommodated.
3 . The pouch bag for the secondary battery according to claim 1 , wherein the protrusion portion includes a plurality of protrusions on the surface of the first inner resin layer, the plurality of protrusions being spaced apart from each other along a linear dimension extending along the surface of the first inner resin layer and wherein the protrusion fixing portion includes a plurality of grooves, the plurality of grooves being spaced apart from each other along a linear dimension extending along the surface of the second inner resin layer.
4 . The pouch bag for the secondary battery according to claim 1 , wherein the protrusion protrudes in the form of a spherical column or a polygonal column, and the groove is configured to receive the protrusion therein.
5 . The pouch bag for the secondary battery according to claim 1 , wherein the protrusion is elongated along a continuous line in an axial dimension on the surface of the first inner resin layer, and the groove is elongated along a continuous line in the axial dimension on the surface of the second inner resin layer.
6 . The pouch bag for the secondary battery according to claim 1 , wherein the opening and closing portion is configured to be opened and closed by fitting and disengaging the protrusion portion within the protrusion fixing portion.
7 . A pouch type secondary battery comprising:
the pouch bag according to claim 1 ;
an electrode assembly accommodated in the pouch bag; and
an electrolyte solution charged in the pouch bag.
8 . The pouch bag for the secondary battery according to claim 1 , wherein the second planar surface of the second inner resin layer does not include a protrusion protruding therefrom.
9 . The pouch bag for the secondary battery according to claim 1 , wherein the first planar surface of the first inner resin layer does not include a groove recessing therefrom.