Water-resistant and anti-flatulence aluminum-plastic film for packaging lithium battery and preparation method of water-resistant and anti-flatulence aluminum-plastic film

Abstract

The invention discloses a water-resistant and anti-flatulence aluminum-plastic film for packaging a lithium battery and a preparation method of the water-resistant and anti-flatulence aluminum-plastic film. The water-resistant and anti-flatulence aluminum-plastic film is characterized by sequentially comprising a scratch-resistant layer, an aluminum foil layer, a chemical protection layer, an absorption layer and a barrier layer from outside to inside, wherein adhesive layers are arranged between the scratch-resistant layer and the aluminum foil layer, between the chemical protection layer and the absorption layer and between the absorption layer and the barrier layer; and the aluminum foil layer and the chemical protection layer are formed together. The water-resistant and anti-flatulence aluminum-plastic film is formed by the steps of firstly preparing the scratch-resistant layer and forming the chemical protection layer, the absorption layer formed by a gas absorption layer and a water absorption layer, a mechanical support layer, a low-temperature heat seal layer and the barrier layer on the surface of aluminum foil; and then coating the adjacent surfaces of the scratch-resistant layer and the aluminum foil layer, the adjacent surfaces of the chemical protection layer and the absorption layer and the adjacent surfaces of the absorption layer and the barrier layer with the adhesive layers, and simultaneously compounding the scratch-resistant layer, the aluminum foil layer, the chemical protection layer, the absorption layer and the barrier layer through a roller press. The water-resistant and anti-flatulence aluminum-plastic film has water-resistant and anti-flatulence functions. By adopting the water-resistant and anti-flatulence aluminum-plastic film, the security of the lithium battery can be improved and the service life of the lithium battery can be prolonged.

Description

technical field [0001] The invention relates to a lithium battery packaging material. Specifically, it is an aluminum-plastic composite film for flexible packaging of polymer lithium-ion batteries. Background technique [0002] Polymer lithium-ion battery is the most advanced secondary battery in the world today. Its battery has high specific energy and fast charging and discharging speed. It has gradually replaced lithium-ion battery and is used in mobile phones, notebook computers, MP3, PDA, DV and other digital products. . [0003] The gas swelling phenomenon of lithium battery is the main factor affecting the safety of the battery, which will cause the performance of the battery to decline. The electrolyte of polymer lithium-ion batteries is mostly composed of organic solvents with strong corrosion and permeability and lithium salts that are easily hydrolyzed. During storage, the electrolyte is easy to oxidize and delaminate the inner film of lithium-ion batteries, cau...

AI Technical Summary

Problems solved by technology

[0004] Since the polymer lithium-ion battery electrolyte is mostly composed of corrosive and permeable organic solvents and easily hydrolyzed lithium salts, when external moisture and air infiltrate, resulting in CO in the battery 2 When significantly increased, a considerable amount of O 2 and N 2 , and the entry of water vapor will cause chemical oxidation, swelling and other problems in the electrolyte, and the phenomenon of gas swelling will also lead to problems such as the reduction of the service life of the battery

[0005] The aluminum-plastic film barrier layer of flexible packaging disclosed in the prior art uses a single-layer polyamide barrier layer. Although the barrier performance is good, the tear strength is poor and the toughness is insufficient. It is easy to tear during battery processing processes such as folding and stamping, resulting in packaging Integral destruction

[0006] In addition, the barrier layer of flexible packaging aluminum-plastic film disclosed in the technology is a single-layer modified polypropylene barrier layer, which has good tensile strength, tensile strength, corrosion resistance and insulation, but poor barrier performance. Gas and moisture will often enter the packaging, which will affect the safety and life of lithium-ion batteries

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