Aluminum plastic film for lithium battery

Aluminum plastic film is one of the five materials of lithium-ion battery, which is the packaging material of soft pack lithium battery. The aluminum plastic film consists of five layers: the outer nylon layer / adhesive / the middle aluminum foil / adhesive / the inner thermal seal layer. Each layer has high functional requirements.
The basic structure of the flexible battery is similar to that of the cylinder and the square. They are positive pole, negative pole, diaphragm, insulating material, positive and negative pole ear and shell. Only the topic of the flexible battery is aluminum-plastic film.



The structure of aluminum plastic film is as shown in the figure above: the outermost layer is nylon layer, the middle layer is aluminum foil, the inner layer is thermal seal layer, and each layer is bonded with adhesive.
Aluminum plastic film is required to have the following characteristics: high barrier; good heat sealing performance; material resistance to electrolyte and strong acid corrosion; good ductility, flexibility and mechanical strength.
The role of aluminum plastic film in lithium ion battery
Aluminum plastic film is one of the five materials of lithium-ion battery, which is the packaging material of soft pack lithium battery. The aluminum plastic film consists of five layers: the outer nylon layer / adhesive / the middle aluminum foil / adhesive / the inner thermal seal layer. Each layer has high functional requirements.
Requirements of aluminum plastic film for lithium ion battery
The barrier ability, puncture resistance, electrolyte stability, high temperature resistance and insulation of aluminum-plastic film affect the performance of lithium-ion battery. Any lack of any aspect may lead to the degradation of battery performance and direct scrap. At present, Japanese enterprises have the most advanced precision coating technology in the world.
Aluminum plastic film technology of lithium ion battery
Dry process and hot process are the main production processes of aluminum plastic film. The dry process is formed by pressing aluminum and polypropylene directly after bonding with adhesive, and the hot process is formed by pressing aluminum and polypropylene with MPP, followed by heating and boosting slowly.
The aluminum plastic film produced by dry method is thin, has good appearance, excellent deep drawing performance and short-circuit resistance, and has simple process and low cost. However, compared with thermal method, it has poor electrolyte resistance and water resistance; the advantages of thermal method are good electrolyte resistance and water resistance, but the deep drawing forming performance and short-circuit resistance are not as good as dry method, and its appearance and cutting performance are poor.