Aluminum-plastic composite film-the neglected "profiteering" market

One side is the unsalable 4,400 yuan, and the other side is the arrogant 10 million.The market of aluminum-plastic film for lithium batteries is really Don't ignore it anymore!

 

The five major materials of lithium ion battery:positive Machine, material; negative electrode material; electrolyte; lithium battery diaphragm; aluminum-plastic composite film.Among them, there are many reports on positive and negative materials, electrolytes and lithium battery separators, and there are also many domestic enterprises.However, aluminum-plastic composite film, a "profitable" material, has been neglected for a long time for various reasons.

 

According to statistics, in 2013, China's annual output of batteries was 3.5 billion, and the amount of aluminum-plastic composite film was 50-60 million square meters.

 

Lithium polymer battery is the battery with the highest capacity, lightest weight and highest safety among lithium batteries.In terms of shape, lithium polymer batteries have the characteristics of ultra-thin, and can be made into batteries of any shape and capacity to meet the needs of various products.This type of battery can reach a minimum thickness of 0.5mm.Its nominal voltage is the same as that of Li-ion ​​is also 3.6 or 3.7V, no memory effect.

 

Polymer soft pack batteries are deeply loved by digital products, and will also be the mainstream direction of wearable lithium batteries in the future.

 

Currently launched products such as:i-Watch, i-PAD, Huawei's mate-7, Xiaomi's various series of mobile phones basically use polymer soft pack batteries, one of the important components of polymer soft pack batteries It is an aluminum-plastic composite film.

 

Structure of aluminum-plastic composite film

 

Aluminum plastic film is composed of five layers of outer nylon layer/adhesive/intermediate aluminum foil/adhesive/inner heat sealing layer, and each layer has relatively high functional requirements.

 

There are only a few domestic aluminum-plastic film manufacturers whose indexes reach the DNP index.Most of them are battery fluid resistance and deep drawing.The domestic drawing depth is about 5mm, and the foreign one can generally reach 8mm , and even reached 15mm.It can be seen that the domestic performance needs to be improved.

 

 

The performance of domestic aluminum plastic film lags behind

 

At present, domestic aluminum-plastic films are used in the lithium battery industry.There are basically no products due to performance reasons.There are only a few experimental products.

 

The main restricting factors are:the domestic aluminum foil has insufficient elongation rate, and the supporting BOPA (biaxially oriented nylon) production enterprises have not really invested in related technologies, which makes the elongation rate of the two materials cannot be Unite.

 

Main domestic aluminum-plastic film manufacturers include:China Aluminum Group Huaxi Aluminum Co., Ltd., Dongguan Zhuogao Electronic Technology Co., Ltd., Zhuhai Saiwei Electronic Materials Co., Ltd., Shanghai Zijiang New Materials Co., Ltd., Guangdong Fosu Jinhui New Materials Co., Ltd.

 

Disadvantages of China's aluminum-plastic composite film:

 

 

1.The surface treatment process of aluminum foil is backward, and it adopts water washing and degreasing and "chromic anhydride" passivation treatment, which causes great pollution.Water has surface tension, and the oil in the micropores of the aluminum foil is not cleanly treated, causing defects in the subsequent composite process.

 

2.The aluminum foil after water treatment will produce "hydrogen embrittlement", resulting in the folding resistance of the domestic aluminum-plastic composite film never reaching the Japanese level.

 

3.The CPP polymer is directly poured on the surface of the unstretched aluminum foil.When the high-heat polymer encounters the surface of the high thermal conductivity aluminum foil, it curls rapidly, resulting in layered crystallization, resulting in many defects.

 

4.The surface of the aluminum foil is not coated with a UV layer, resulting in insufficient stiffness of the aluminum foil.Dry lamination is easy to wrinkle, and it cannot be used as a wide-width product.The rejection rate is extremely high.