Aluminium-plastic film and preparation method for same

Abstract

The invention discloses an aluminium-plastic film and a preparation method for the same. The aluminium-plastic film is composed of a blocking layer, a matrix layer, an aluminium film layer, an adhesive film layer and a CPP (castpolypropylene) film layer which are sequentially stacked. The preparation method for the aluminium-plastic film comprises the following steps of: 1) using polyimide (PI) for preparing a matrix, and performing pre-treatment on the surface of the matrix; 2) coating a blocking coating on one surface of the preheated PI matrix; 3) forming the aluminium film layer on the other surface of the PI matrix by a PVD (physical vapour deposition) method; 4) coating the adhesive layer on the aluminium film layer; and 5) compounding the CPP film on the adhesive layer. The aluminium-plastic film disclosed by the invention provides a coloured matrix film layer, as well as is extremely high in strength, air tightness, blocking property, acid-base resistance and electrolyte resistance, and convenient to identify; the aluminium film layer generated by virtue of the PVD method is extremely high in peeling strength with the matrix layer; and the functional aluminium-plastic film prepared by the method is excellent in machining performance, shielding effectiveness, blocking performance and the like, and capable of being used for external packaging for lithium batteries and high-performance batteries. Moreover, the aluminium-plastic film is low in cost, excellent in bending and tensile property, environment-friendly, and easy in technical processing.

Description

technical field [0001] The invention relates to a packaging material for an explosion-proof soft-pack lithium battery and a preparation method thereof, in particular to a lithium battery and a battery production with color identification, explosion-proof film, outer packaging, soft-pack material aluminum-plastic film, and shielding material Aluminum plastic film and its preparation method. Background technique [0002] At present, with the development of the lithium battery industry, the demand for aluminum-plastic packaging films is increasing. At the same time, the pursuit of high-performance lithium batteries has attracted more and more attention to the requirements for aluminum-plastic films. [0003] In view of the problem that the current packaged lithium battery is easy to release gas during use, the pressure increases, and the explosion is caused. The new flexible packaging material on the market is flexible and can expand to release the pressure, thereby preventing ...

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Problems solved by technology

[0004] For example, the invention patent application with the publication number CN101350370A discloses a packaging film using PP ethylene-methacrylic acid copolymer / aluminum foil / ethylene-methacrylic acid copolymer / PP. This series of films has better explosion-proof performance, but the bonding layer Poor toughness and heat-sealing bonding strength; another example is that the invention patent application with the application publication number CN101992570A discloses a lithium battery packaging aluminum-plastic film, which mainly includes a protective layer, an aluminum foil layer and a heat-sealing layer, and the protective layer and the aluminum foil layer, and the heat-sealing layer and the aluminum foil layer are respectively bonded and compounded by an adhesive layer. The surfaces of the layer and the heat-sealing layer are treated by plasma technology surface grafting, and then the protective layer and the aluminum foil layer, as well as the aluminum foil layer and the heat-pressed layer are respectively heat-pressed and composited with the two sides of a glued layer.

Although the aluminum-plastic film for lithium battery packaging has high chemical resistance, moisture insulation, oxygen insulation, packaging adhesion and explosion-proof, it is suitable for flexible packaging lithium batteries, but its aluminum foil layer is mechanically processed by bonding the glued layer with heat and pressure. Poor performance, unreliable bonding, and not environmentally friendly due to the use of adhesives

[0005] In the production of lithium batteries, due to the strong corrosion of the electrolyte, it is necessary to solve the corrosion resistance of the aluminum film. However, due to the poor mechanical processing performance of traditional packaging materials, they are easily damaged during the preparation and molding of lithium batteries, which increases the use of lithium batteries. The possibility of leakage, damage and explosion during the process; in addition, due to the poor identifiability of many materials in the battery processing process, it is easy to cause confusion in material processing; resulting in difficulties in lithium battery processing and unstable quality of the prepared batteries

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