Lithium battery separator longitudinal stretching production line

The main function of the longitudinal separator in lithium batteries is to separate the positive and negative electrodes of the battery, preventing short circuits caused by contact between the two poles. The micropores in the film allow lithium ions to pass through, forming a charging and discharging circuit. The separator is the core and key material in lithium batteries, and also the high value-added material with the highest technical barrier in lithium batteries. Its performance determines the interface structure, internal resistance, battery capacity, lifespan, and safety performance of the battery.
In the structure of lithium batteries, the separator is one of the key inner components. The performance of the separator determines the interface structure, internal resistance, and other characteristics of the battery, directly affecting its capacity, cycling, and safety performance. A high-performance separator plays an important role in improving the overall performance of the battery. A simple description of a separator is a porous plastic film, which is the most technically challenging high value-added material in lithium battery materials, accounting for about 20% -30% of the cost of lithium batteries.
Jinweier Machinery specializes in manufacturing PP/PE lithium battery separator dry single pull extrusion production line. The production line is equipped with our company's MDO (Unidirectional Stretching) unit, which can achieve stable and uniform stretching of products, uniform pores, and greatly reduce the defect rate.

The lithium battery separator production line is divided into:Dry unidirectional stretching production line; Dry biaxial stretching production line; Wet extraction bidirectional stretching production line.
Dry uniaxial stretching production line:The dry uniaxial stretching process is a method of producing hard elastic fibers, using PP or PE as the main raw material, mixing various grades of auxiliary materials, and thoroughly stirring to prepare low crystallinity high orientation polypropylene or polyethylene films, and then annealing at high temperature to obtain high crystallinity oriented films. This type of film is first stretched at low temperatures to form micro defects, and then the defects are pulled apart at high temperatures to form micropores. In terms of equipment, after extrusion molding by casting method, the multi-layer composite is subjected to unidirectional stretching by a laminating machine. Then, the stretched multi-layer separator is layered and cut by a layering machine and a slitting machine to produce unidirectional stretched lithium battery separators. The Jinweier lithium battery dry single pull production line is equipped with high-precision detection instruments and adopts a production process jointly developed with well-known Chinese research institutions. It mainly produces lithium-ion battery separators with different specifications ranging from 16 μ m to 40 μ m thickness. Application scope: Large lithium-ion power batteries (electric vehicles, electric motorcycles, electric tools, large energy storage equipment, military large batteries)
Dry biaxial stretching production line:The dry biaxial stretching process is a process with independent intellectual property rights developed by the Institute of Chemistry of the Chinese Academy of Sciences in the early 1990s. Using PP as the main raw material, β - crystal type improver with nucleation effect is added to polypropylene. By utilizing the difference in density between different phases of polypropylene, crystal type transformation occurs during the stretching process to form micropores, which are used to produce single-layer PP membrane battery isolation film. In terms of equipment, after extrusion molding by the casting method, the biaxially stretched lithium battery separator is produced by winding and slitting in both directions. The Jinweier lithium battery separator equipment is equipped with high-precision detection instruments and adopts a production process jointly developed with well-known Chinese research institutions. It mainly produces dual pull lithium-ion battery separators with different specifications ranging from 12 μ m to 40 μ m in thickness. At present, more than one-third of China's production capacity uses dry double pull technology, and the products occupy a large proportion in the mid to low end market
Wet process biaxial stretching production line: The wet process uses PE as the main raw material to mix liquid hydrocarbons or some small molecular substances with polyolefin resin, stir thoroughly, heat and melt to form a uniform mixture, then cool down for phase separation, press the film, heat the film to near the melting point temperature, perform biaxial stretching to orient the molecular chains, and finally hold for a certain period of time. Volatile substances are used to wash away residual solvents to prepare interconnected microporous film materials. In terms of equipment, the wet process biaxially stretched lithium battery separator is produced by extrusion molding using the casting method, followed by extraction process to form holes, and then longitudinal and transverse stretching followed by winding and slitting. The Jinweier wet dual pull lithium battery separator line is equipped with high-precision detection instruments and adopts a production process jointly developed with well-known Chinese research institutions. It mainly produces lithium-ion battery separators with different specifications ranging from 8 μ m to 25 μ m thickness. Application scope: High performance lithium-ion batteries, etc.

(Dry process single pull lithium battery separator and electron microscopy image)
Product Features:Lithium ion battery separator is a polymer functional material with nanoscale micropores. Rechargeable lithium-ion batteries have the characteristics of high specific energy, long cycle life, and no memory effect, as well as safety, reliability, and fast charging and discharging. It meets the great development needs of energy and environmental protection in various countries today, and its usage in various industries is rapidly increasing.
1. Good thickness uniformity and even distribution of micropores are beneficial for the consistency of lithium-ion batteries;
2. Low micro pore tortuosity, good breathability, strong liquid retention ability, and low internal resistance of the battery;
3. High temperature resistance, no transverse thermal shrinkage, high film breaking temperature, good safety performance;
4. High tensile strength and good mechanical properties;
5. The standard width of the production line is 1000-2400mm, and the specific specifications are determined by the production process and can be customized.
Main uses of the product:Various systems of power lithium-ion batteries such as electric vehicles, electric motorcycles, electric bicycles, and electric tools, large-scale energy storage lithium-ion batteries, as well as various digital lithium-ion batteries.

Parameters of lithium battery separator dry single pull production line (please consult sales engineer for details)

model	Single screw GWS75	Single screw GWS90	Pingshuang GWP75	Single screw GWS75/90/75
raw material	PP、PE	PP、PE	PP、PE	PP、PE
Product structure	single layer	single layer	single layer	A/B/A
Product width	1000mm	1000mm	1000mm	1000mm
Product thickness	16um-25um	16um-25um	16um-25um	12um-38um
Extrusion output	70KG/H-100KG/H	90KG/H-110KG/H	90KG/H-110KG/H	100KG/H-130KG/H
linear velocity	100 m/min	100 m/min	100 m/min	100 m/min