Pouch film for secondary battery and manufacturing method thereof
AssigneeLG Energy Solution, Ltd.
InventorYong Kim
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Abstract
A pouch film for a secondary battery and a method for manufacturing the same. In some embodiments, the pouch film includes a stretchable auxiliary layer that is a multi-layered structure comprising a plurality of layers, wherein layers in the plurality of layers have different elongation rates. The stress at the interface of each layer is relieved and the moldability of a pouch is improved. The risk of breakage of a pouch is significantly reduced and defect rates are reduced in a pouch manufacturing process, thereby reducing manufacturing costs.
Claims6
A pouch film for a secondary battery for manufacturing a pouch-type battery case, the pouch film comprising:
- a sealant layer formed as the innermost layer;
- a surface protection layer formed as the outermost layer;
- a gas barrier layer laminated between the sealant layer and the surface protection layer;
- and
- a stretchable auxiliary layer laminated between the gas barrier layer and the surface protection layer,
- wherein the stretchable auxiliary layer is a multi-layered structure comprising a plurality of layers, and
- wherein the plurality of layers includes:
- a first modification PET layer having an elongation rate of 45% to 55%,
- a second modification PET layer bonded to the first modification PET layer, the second modification PET layer having an elongation rate of 65-75%, and
- a third modification PET layer bonded to the second modification PET layer, the third modification PET layer having an elongation rate of 85% to 95%.
A method for manufacturing a pouch film for a secondary battery, the method comprising:
- laminating a gas barrier layer on a sealant layer;
- laminating a stretchable auxiliary layer on the gas barrier layer, wherein the stretchable auxiliary layer is a multi-layered structure comprising a plurality of layers;
- and
- laminating a protection layer on the stretchable auxiliary layer, such that the sealant layer, gas barrier layer, stretchable auxiliary layer, and protection layer are sequentially arranged,
- wherein the plurality of layers includes:
- a first modification PET layer having an elongation rate of 45% to 55%,
- a second modification PET layer bonded to the first modification PET layer, the second modification PET layer having an elongation rate of 65-75%, and
- a third modification PET layer bonded to the second modification PET layer, the third modification PET layer having an elongation rate of 85% to 95%.
Dependencies are inferred from the claim text.