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market@legion.com.cn
Aluminum plastic film (ALF) is a key material for flexible packaging of lithium battery cells. It is a multi-layer composite with high strength and high barrier composed of various plastics, aluminum foil and adhesives. After the single cell is assembled, it is sealed with aluminum plastic film to form a battery. The aluminum plastic film plays the role of protecting the contents. Aluminum plastic composite film for soft pack lithium battery has good barrier property, electrolyte stability, cold stamping formability, puncture resistance and insulation. It is the most critical safety link in soft package lithium battery and a composite material with extremely strict technical requirements.
About ALF
Aluminum plastic film (ALF) is a key material for flexible packaging of lithium battery cells. It is a multi-layer composite with high strength and high barrier composed of various plastics, aluminum foil and adhesives. After the single cell is assembled, it is sealed with aluminum plastic film to form a battery. The aluminum plastic film plays the role of protecting the contents. Aluminum plastic composite film for soft pack lithium battery has good barrier property, electrolyte stability, cold stamping formability, puncture resistance and insulation. It is the most critical safety link in soft package lithium battery and a composite material with extremely strict technical requirements.
Material structure and production process
1.Typical product structure
The structure of typical aluminum plastic film is: on (surface layer) / Al (aluminum foil layer) / CPP (resin layer). Among them, the outermost layer is usually nylon layer or composite layer of pet and nylon, which is mainly used to protect against pollution, corrosion and external force damage; the intermediate aluminum foil layer is the base material, which plays the role of waterproof, barrier and product shape forming; polypropylene is the hot sealing layer, which is mainly used for sealing and bonding, and it can separate the aluminum layer from the battery core, so as to prevent the electrolyte leakage of packaging from corroding aluminum The composite layer of foil, adhesive or adhesive resin mainly plays the role of strong connection between layers.
2.Production technology
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| 图1 Two production processes | 图2 Production flow diagram |
3.Material structure of products
LGA-G：LGA-088G/LGA-113G/LGA-152G
LGA-E：LGA-152E/LGA-156E
LGA-R：LGA-113R/ LGA-152R/LGA-156R
Model
| Type | Thickness | Width | Length |
| LGA-088G | 88µm | 400mm/480mm | 200m~400m |
| LGA-113G | 113µm | 320mm/400mm/480mm | |
| LGA-113R | 113µm | 320mm/400mm/480mm | |
| LGA-152G | 152µm | 400mm/480mm | |
| LGA-152E | 152µm | 400mm/480mm | |
| LGA-152R | 152µm | 400mm/480mm | |
| LGA-156E | 156µm | 400mm/480mm | |
| LGA-156R | 156µm | 400mm/480mm | |
| Remarks | ★ According to the requirements of customers, the maximum width is 900mm and the minimum width is 50mm. |
Features
It has very high barrier property, which is 10000 times higher than that of ordinary aluminum plastic composite film;
It has excellent electrolyte resistance;
It has good cold stamping formability;
It has excellent heat sealing strength, which is conducive to battery packaging and processing;
It has excellent stamping formability;
With excellent electrolyte corrosion resistance, through the creative anti-corrosion treatment process, the product does not contain heavy metals;
The results show that the corrosion resistance is excellent; the aluminum coating after stamping deformation has a certain degree of self-healing to ensure the long-term reliability of the battery;
It has excellent heat sealing performance, high temperature resistance and strong insulation: the sealing performance of side seal, top seal and sealing after liquid injection reaches or exceeds the same industry level; it can maintain high heat sealing strength in a wide temperature range, which is beneficial to the processing and durability of battery. At the same time, the insulation, friction coefficient, puncture resistance, bending performance, water permeability, oxygen permeability, printing performance and other physical properties have passed the strict test.
Physicochemical properties
| Items | LGA-088G | LGA-113G | LGA-113R | LGA-152G | LGA-152E | LGA-152R | LGA-156E | LGA-156R | |
| thickness µm | 88±5% | 113±5% | 113±5% | 152±5% | 152±5% | 152±5% | 156±5% | 156±5% | |
| peel strength N/15mm | ON/AL | ≥3 | ≥3 | ≥3 | ≥3 | ≥3 | ≥3 | ≥3 | ≥3 |
| CPP/AL | ≥6 | ≥6 | ≥6 | ≥8 | ≥8 | ≥8 | ≥12 | ≥12 | |
| heat sealing strengh N/15mm | ≥40 | ≥40 | ≥60 | ≥60 | ≥60 | ≥60 | ≥70 | ≥70 | |
| electrolyte resistanceN/15mm | peel strength（CPP/AL) | ≥5 | ≥6 | ≥6 | ≥8 | ≥8 | ≥8 | ≥8 | ≥8 |
| heat sealing strength | ≥30 | ≥50 | ≥50 | ≥50 | ≥50 | ≥50 | ≥60 | ≥60 | |
| electrical resistance of protective layer Corrosive solution | Y | Y | Y | Y | Y | Y | Y | Y | |
| formability mm | ≥5 | ≥5 | ≥5 | ≥6 | ≥6 | ≥6 | ≥6 | ≥6 | |
| puncture intensity N | ≥18 | ≥20 | ≥20 | ≥20 | ≥20 | ≥22 | ≥22 | ≥22 | |
| tensile strength N/15mm | ≥80 | ≥100 | ≥100 | ≥100 | ≥100 | ≥110 | ≥110 | ≥110 | |
| halogen ppm | Free | Free | Free | Free | Free | Free | Free | Free | |
| RoHS ppm | Free | Free | Free | Free | Free | Free | Free | Free | |
Hot sealing strength：temperature180℃、surface pressure 0.6MPa、time 3s； Test conditions of electrolyte resistance：immerse the sample into electrolyte，85℃*24hr，EC:DEC:DMC=1:1:1,LiPF6 1mol/L； Corrosion resistance of protective layer: drop the electrolyte on the surface of the outer protective layer, wipe and observe after 1h, there is no residual imprint, dissolution, discoloration and stratification, "n" is not corrosion-resistant; "Y" is excellent corrosion resistance； Molding performance: Lianjing double pit mold, mold size 65 * 80mm, top angle R = 1.5; Test equipments: tensile testing machine, heat sealing instrument, stamping machine, electric constant temperature water bath pot, test method of thickness as GB/T 6672-2001。 | |||||||||
It is mainly used in 3C consumer electronic battery, energy storage battery, power battery, etc., such as mobile communication, digital camera, notebook computer, MP3, intelligent wear, UAV, electric vehicle, etc.