Analysis on the Development Status of China's Lithium Battery Aluminum Plastic Film Industry in 2016 [Figure]]

Aluminum plastic film is divided into food grade aluminum plastic film and lithium battery aluminum plastic film. Food grade aluminum plastic film is a common packaging material, such as potato chips, capsule packaging and so on. However, the aluminum-plastic film process for polymer soft-packed lithium batteries is much more difficult, and it was jointly developed by Showa and SONY in 1999. At present, it is the core material that has not yet achieved large-scale localization in the core, and the technical barriers are extremely high. Aluminum plastic film has extremely high requirements in related performance, far exceeding the diaphragm, positive electrode, negative electrode and electrolyte. The requirements mainly involve four aspects: barrier ability, puncture resistance, electrolyte stability, high temperature resistance and insulation. Any lack of any aspect may lead to a decrease in battery performance and direct scrap. It uses precision coating technology production, at present, the world's more advanced precision coating technology is mainly mastered by Japanese enterprises.

Important indicators of aluminum plastic film

Data source: public data collation

Aluminum-plastic film plays a key role in soft-packed lithium batteries, generally accounting for about 15-20% of the cost of batteries. However, due to its high technical barriers, domestic aluminum plastic film market share is very small. At present, 90% of the domestic aluminum-plastic film market is monopolized by Japanese manufacturers, mainly DNP (Great Japan Printing), Showa Electric and T & T, while domestic aluminum-plastic film accounts for less than 5%.
The main raw materials of lithium battery cells have basically formed import substitution, and aluminum-plastic film as a lithium-electric material that has not yet been localized, its gross profit margin is as high as 60-80% (the current price of imported aluminum-plastic film exceeds 30 yuan/square meter, domestic about 25 yuan/Square meters). It is conceivable that the domestic manufacturers who took the lead in the layout of the aluminum-plastic film industry and achieved technological breakthroughs can truly snatch this piece of fat from the mouths of foreign giants.

Global aluminum plastic film market share, 2014

Data source: public data collation

Cost composition of soft pack lithium battery

Data source: public data collation

Aluminum-plastic film is a three-layer film, each layer of film is bonded by adhesive: the outermost nylon layer (ON) mainly plays a protective role, protecting the aluminum layer from being scratched and oxidized; The middle aluminum layer (AL) is the matrix material, which plays the role of shaping and blocking. The inner polypropylene (CPP) separates the aluminum layer from the battery core to prevent electrolyte corrosion. At present, the market share of aluminum plastic film accounted for a relatively large two manufacturers Showa Electric, DNP, respectively, the use of dry process and thermal process.

Structure Comparison of Showa Electric Dry Method and DNP Thermal Method

Data source: public data collation

Comparison of Fabrication Methods and Properties of Aluminum Plastic Film by Dry Method and Thermal Method

Data source: public data collation

Why is it difficult to break through the manufacturing technology of aluminum-plastic film, the difficulty lies mainly in the control of the process-the precise control of the reaction conditions. At present, only a few of the indicators of domestic aluminum plastic film manufacturers have reached the DNP index. 1) Tightness. Surface structure and electrolyte resistance of aluminum layer. Domestic aluminum foil surface treatment process is backward, the use of washing to remove oil and "chromic anhydride" passivation treatment, pollution. Water has surface tension, and the oil treatment in the micropores of the aluminum foil is not clean, resulting in defects in the subsequent composite process. The aluminum foil after water treatment will produce "hydrogen embrittlement", resulting in the domestic aluminum-plastic composite film folding resistance has always been less than the Japanese level. 2) Shell depth. The depth of impact is always unsatisfactory. The depth of domestic penetration is about 5mm, even if it is very good, it can reach 8mm abroad, and some even reach 12mm, which is still a certain gap with foreign products. 3) In terms of thickness, the thinnest aluminum-plastic film in China is 70um, and the mass production is 112um, 88um and 72um, while the thinnest aluminum-plastic film in Japan can be 40um (aluminum layer thickness is 30um), and the mass production is also realized for 65um and 48um.

The oligopoly control of the domestic aluminum-plastic film market has caused many battery manufacturers to lose their right to speak in terms of quantity, quality and price. At present, both DNP and Showa Electric have expanded their production on the original basis. DNP's production capacity has reached 6 million square meters/month, and Showa also plans to expand production by 30% on the basis of 2 million square meters/month. Li Village also has a capacity of 2 million m2/month.