Technology of Aluminum Plastics Film for Battery

Looking at the global market for lithium batteries aluminum plastic film, the production technology upgrade. The aluminum plastic membrane production process of batteries is currently mainly a dry process represented by the Japanese Showa and a thermal process represented by the Japanese DNP. The dry process is applied to high energy batteries such as mobile phone batteries and high-power and high-capacity power batteries such as electric vehicles andspecial models; The thermal process can only be applied to batteries with low capacity requirements. The domestic battery aluminum plastic film mostly adopts the heat process, the performance is low. Under the gap, how to break the cocoon? Domestic battery aluminum plastic film enterprises in thinking in action.

Analytic Process

CNKI data show that there is a large gap between domestic battery aluminum plastic film products and foreign products. Only a few indicators of domestic aluminum plastic film manufacturers meet the DNP standard. The production process directly affects the quality of the product: First, the sealing ability is not strong. The domestic aluminum plastic composite film is not able to reach the Japanese standard. Second, the depth of the shell is not enough. The punching depth of domestic aluminum plastic film is about 5mm, and it can reach 8mm to 12mm abroad. Third, the thinness is insufficient. The thinnest aluminum plastic film in China can only achieve 70um. The main problem of product performance is the resistance of electrolytes and impulse depth, especially the reaction conditions and precision control. The difficulty of process control is in the millimetre, the difference is thousands of miles.

Subject to the process technology, the domestic aluminum plastic film is like a pupa trapped in the cocoon.

Litaoyong, deputy general manager and chief technical officer of Mingguan Xincai, analyzed and pointed out: "The heat method is a technical route for thermal extrusion. The thermal stress is relatively large, which is its disadvantage; The dry method is to dry and press together, the thermal stress is small, the aluminum plastic film will not be affected under the state of crystallization, and the punching shell, stretching, and needle holes will be smaller. This is its advantage. "

Shanghai zijiang people believe that: in the two technological routes, the advantage of dry method lies in the deep molding performance, short-circuit performance, appearance, cutting performance, electrolytic liquid resistance, strong water separation, and simple process. The advantages of thermal process mainly focus on electrolytic liquid resistance and water resistance. Other properties need to be improved, and the process is complex.

Improvement of process technology

It is reported that Mingguan New Materials has been used in combination with two kinds of process technologies. The advantage of the dry heat method is that it absorbs the advantages of the dry process while taking into account the advantages of the heat method in the resistance to electrolytes and water resistance. The comprehensive performance of aluminum plastic film in deep forming, appearance, cutting performance, electrolyte resistance and water resistance performance has been comprehensively improved. Through these improvements, the company reached 2.5 million square meters per month in 2018. The product classification includes light, medium and heavy series. The dry heat process was completed and tested experimentally, and it performed well in terms of barrier, protection, process, and stability.

"Water insulation, insulation, corrosion resistance, friction resistance, and compounding are the five major factors that affect the performance of aluminum plastic films. They are also the five directions for domestic aluminum plastic film performance breakthroughs and are the key points for technological improvement. "Relevant experts said.

Some leading enterprises in China also rely on the accumulation of high-performance adhesives for many years, research and development of dry heat recovery method to comprehensively improve the performance of battery aluminum plastic film.

Control process quality

In addition, in the quality control of battery aluminum plastic film products, many domestic enterprises have increased their efforts.

Mingguan new material upgraded the quality control system, applying mature PET composite technology, with the production process, to improve aluminum plastic film cleaning, friction resistance. For the insulation and corrosion resistance of products, the PET structure is used externally, and the corrosion resistance of electrolytes on the surface can resist electrolyte pollution above 24h, basically eliminating electrolyte pollution. High insulation remains at the GΩ level after 1000V DC clicks 500 seconds; The unique modified CPP is used internally to effectively reduce the resistance scrap rate. At the same time, the company adopts the independent research and development of composite structure PP, aluminum foil corrosion resistant coating and special special electrolytic liquid adhesive, better use of thermal process, three-layer protection makes it difficult for electrolytes to invade aluminum foil layer corrosion aluminum foil, protect aluminum plastic film integrity, And has the long-term stable performance of electrolytic liquid. In the production process, the whole process of quality control tracking.

Mingguan New Materials Chief Technical Officer Litaoyong said: "Mingguan New Materials has strict quality control of aluminum plastic film, and has a number of laboratories. Customers need to do water transparent and BSC tests. The import of the main raw materials is in accordance with the 16949 standard. How the materials are inspected and guaranteed, they must be approved by the user before they can be changed. The core equipment is unchanged, the production method is unchanged, the core material is unchanged, and changes in process detection and identification must be approved by the user to ensure quality. "

The company has also done a series of third-party testing and certification, and the product has greatly improved in terms of barrier, protection, process and stability. And through the raw materials, process, inspection and prevention and other strict monitoring, to achieve product process control, ensure product quality.

Shanghai zijiang related personnel said: the company continuously strengthen the production of crafts control, instead of improving the process, work hard on the quality of products, focusing on improving electrolyte resistance, waterproof barrier and deep forming, improve the stability of quality.

Market meeting, look forward to the domestic battery aluminum plastic film, this pupa break out as soon as possible, flying butterfly.

The page contains the contents of the machine translation.