New energy battery packaging film and preparation method thereof

Abstract

The invention relates to the technical field of outer layer materials of aluminum-plastic films for battery packaging, and discloses a new energy battery packaging film and a preparation method thereof.The preparation method comprises the steps that in a molten state and under the action of a free radical initiator, a self-made grafting monomer is grafted to a molecular main chain of LLDPE resin through a free radical graft copolymerization reaction, and epoxy LLDPE master batches are prepared; the preparation method comprises the following steps: based on an epoxy-amido ring-opening reaction mechanism, carrying out melt blending on an epoxy-based LLDPE master batch and PA6 resin to generate a bridging type PA6-LLDPE composite master batch, and carrying out blow molding to prepare a PA6-LLDPE film; a PA6-LLDPE film is used for replacing an outer layer PA6 film in an aluminum plastic film, and the new energy battery packaging film is prepared. The prepared PA6-LLDPE film product can replace an outer layer pure PA6 film of an aluminum plastic film to be used for packaging a battery which is high in product falling risk and few in burrs in the assembling process, so that the beneficial technical effect of reducing the overall production cost of the aluminum plastic film is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum-plastic film outer layer materials for battery packaging, and in particular to a new energy battery packaging film and a preparation method thereof. Background Art

[0002] New energy batteries refer to advanced battery technologies used to store and release electrical energy. The current mainstream technical routes include lithium-ion batteries, sodium-ion batteries and solid-state batteries. The packaging materials of lithium-ion batteries that dominate the market include steel shells, aluminum shells, soft packaging, etc., and the preferred material for soft packaging is aluminum-plastic film. The main structure of the product is an inner heat-sealing layer (made of cast polypropylene CPP, polyethylene PE, ethylene-acrylic acid copolymer EAA), an aluminum foil layer, and an outer buffer protective layer. The material of this protective layer is mainly polyamide PA.

[0003] Since the raw material cost of PA6 is relatively high (the price of PA6 is about 10300-21500 / ton), while the raw material price of polyethylene LLDPE is relatively low (only 7000-7500 / ton), in the outer layer design, LLDPE is planned to replace part of PA6 to reduce the overall production cost of aluminum-plastic film.

[0004] However, LLDPE is a non-polar polymer and PA6 is a strongly polar polymer. This significant difference in polarity results in extremely poor interfacial compatibility between LLDPE and PA6, and very weak intermolecular forces. It is difficult to form a strong and reliable bond between LLDPE and PA6 on the contact surface through a simple co-extrusion process. In other words, the interlayer bonding force of directly extruded composite films is very low, and they are very easy to delaminate, which cannot meet the performance requirements of aluminum-plastic films.

[0005] The present invention cites the following references: Zhang Wenhong's master's thesis "Synthesis and Characterization of Functionalized POSS Monomers" published by Zhejiang University in 2010 disclosed the chemical structure and synthesis method of isobutyloxyheptaphenyltitanium silsesquioxane Ti-POSS. Summary of the Invention

[0006] To address the problem of poor interfacial compatibility between LLDPE and PA6 resins when low-cost LLDPE resin raw materials replace part of high-cost PA6 resin raw materials, the present invention has developed a grafting monomer containing siloxane groups for bridging the raw material interface between LLDPE and PA6. The resulting PA6-LLDPE film product maintains mechanical properties close to those of pure PA6 film products while partially replacing the expensive PA6 raw materials and directly replacing the commonly used maleic anhydride polyethylene adhesive, thereby achieving the technical goal of reducing the overall production cost of aluminum-plastic film.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing a new energy battery packaging film comprises the following steps: Step 1: Based on the silanol condensation reaction mechanism, diphenyldimethoxysilane or dihydroxyphenylsiloxy Ti-POSS is used as a bridging structure, and vinyldimethylethoxysilane and (3-glycidoxypropyl)dimethylethoxysilane provide functional group raw materials to synthesize a siloxane-type grafting monomer containing vinyl and epoxy groups or a siloxane@Ti-POSS-type grafting monomer; Step 2: In a molten state and under the action of a free radical initiator, the grafting monomer is grafted onto the molecular main chain of the LLDPE resin through a free radical graft copolymerization reaction to prepare an epoxy LLDPE masterbatch; Step 3: Based on the epoxy-amine ring-opening reaction mechanism, the epoxy-based LLDPE masterbatch is melt-blended with the PA6 resin to generate a bridged PA6-LLDPE composite masterbatch, and the composite masterbatch is blow-molded to produce a PA6-LLDPE film; Step 4: Use PA6-LLDPE film to replace the PA6 film in the outer layer of the aluminum-plastic film to produce a new energy battery packaging film.

[0008] Preferably, the preparation method of the siloxane-type grafting monomer is: In the method, diphenyldimethoxysilane is first hydrolyzed in a mixed solvent of toluene and deionized water, and then condensed with the hydrolysis product of vinyldimethylethoxysilane under the catalysis of dibutyltin dilaurate. The condensation reaction is then carried out with the hydrolysis product of (3-glycidoxypropyl)dimethylethoxysilane, and the molar ratio of diphenyldimethoxysilane, vinyldimethylethoxysilane and (3-glycidoxypropyl)dimethylethoxysilane is controlled to be 1:(0.9-0.99):(1.0-1.1) to prepare a siloxane-type grafting monomer.

[0009] Preferably, the preparation method of the siloxane@Ti-POSS type grafting monomer is: The isobutoxy functional group in isobutoxyheptaphenyltitanium silsesquioxane Ti-POSS reacts with the silanol functional group obtained by hydrolysis of phenyltrimethoxysilane to undergo deisobutanol reaction to generate dihydroxyphenylsiloxy Ti-POSS. In a mixed solvent of toluene and deionized water, under the catalysis of dibutyltin dilaurate, 1 molar equivalent of dihydroxyphenylsiloxy Ti-POSS first undergoes condensation reaction with (0.9-0.99) molar equivalents of the hydrolysis product of vinyldimethylethoxysilane, and then with (1.0-1.1) molar equivalents of the hydrolysis product of (3-glycidoxypropyl)dimethylethoxysilane to form a siloxane@Ti-POSS type grafted monomer.

[0010] Preferably, the initiator is dicumyl peroxide or tert-butyl perbenzoate.

[0011] Preferably, the preparation method of the epoxy LLDPE masterbatch is: melt extrusion granulation through a twin-screw extruder, and the temperatures of zones 1-4 are: 105-115°C, 120-130°C, 130-140°C, and 130-140°C, respectively.

[0012] Preferably, the preparation method of the PA6-LLDPE film is: blow molding the film through an extruder, the temperatures of the three zones of the extruder barrel are: fixed conveying zone 170-190°C, melting zone 210-230°C, melt conveying zone 210-230°C, and head temperature is 210-220°C.

[0013] Preferably, the new energy battery packaging film is an aluminum-plastic film, the outer layer of the aluminum-plastic film is a PA6-LLDPE film, and the formula of the PA6-LLDPE film is: (70-90) wt% PA6 resin, (10-30) wt% epoxy LLDPE masterbatch; The formula of the epoxy-based LLDPE masterbatch is: (79.85-89.95) wt% LLDPE resin, (0.05-0.15) wt% dicumyl peroxide and (10-20) wt% siloxane or siloxane@Ti-POSS grafting monomer.

[0014] Preferably, the PA6-LLDPE film has a thickness of 15-30 μm.

[0015] The beneficial effects of the present invention are as follows: Based on the principle of molecular design, siloxane-type grafting monomers and siloxane@Ti-POSS-type grafting monomers containing vinyl and epoxy groups were synthesized. The specific mechanism is as follows: Mechanism 1: Based on the silanol condensation reaction mechanism, diphenyldimethoxysilane is used as the bridging structure, vinyldimethylethoxysilane and (3-glycidoxypropyl)dimethylethoxysilane are used as functional group raw materials to synthesize the siloxane-type grafting monomer; Mechanism 2: The hydrolysis product of phenyltrimethoxysilane reacts with isobutyloxyheptaphenyltitanium silsesquioxane (also known as Ti-POSS) to undergo a deisobutylation reaction to generate dihydroxyphenylsiloxy Ti-POSS. Based on the silanol condensation reaction mechanism, a siloxane@Ti-POSS grafting monomer is synthesized using dihydroxyphenylsiloxy Ti-POSS as a bridging structure and vinyldimethylethoxysilane and (3-glycidoxypropyl)dimethylethoxysilane as functional group raw materials. In the molten state and under the action of a free radical initiator, a grafting monomer containing a vinyl group is grafted onto the main chain of the LLDPE resin through a free radical graft copolymerization reaction to prepare an epoxysiloxane type LLDPE masterbatch or a silicone@Ti-POSS type epoxy LLDPE masterbatch; Based on the epoxy-amine ring-opening mechanism, epoxysiloxane-based LLDPE masterbatch or silicone@Ti-POSS-based epoxy-based LLDPE masterbatch was used as a compatibilizer, melt-blended with polyamide PA6, and then blow-molded to produce PA6-LLDPE film. The experimental results show that the PA6-LLDPE film product prepared by the present invention has the beneficial technical effect of significantly improving the impact resistance and water absorption performance while maintaining the performance close to that of pure PA6 film in terms of fracture resistance and puncture resistance. PA6-LLDPE film products can replace the pure PA6 film on the outer layer of aluminum-plastic film to package batteries with high risk of falling and less burrs during the assembly process, achieving the beneficial technical effect of reducing the overall production cost of aluminum-plastic film. DETAILED DESCRIPTION Experimental Example 1:

[0016] The synthesis mechanism of the siloxane grafting monomer is as follows: based on the silanol condensation reaction mechanism, diphenyldimethoxysilane first reacts with vinyldimethylethoxysilane to introduce a vinyl functional group, and then reacts with (3-glycidoxypropyl)dimethylethoxysilane to introduce an epoxy functional group to generate a siloxane grafting monomer; The experimental steps for siloxane-type grafting monomers are: 2.50 g of diphenyldimethoxysilane was added to 30 mL of toluene and 5 mL of deionized water, stirred and hydrolyzed at 70°C for 1.5 h, 10 mg of dibutyltin dilaurate and 1.33 g of vinyldimethylethoxysilane were added, and the mixture was kept at 70°C for 1.5 h. 2.23 g of (3-glycidoxypropyl)dimethylethoxysilane was then added, and the mixture was kept at 60°C for 3 h. Toluene and small molecular by-products were removed by rotary evaporation under reduced pressure to obtain a siloxane-type graft monomer. The chemical structure of the siloxane grafting monomer is: ; The hydrogen spectrum characterization results of the siloxane-type grafted monomer are as follows: 1H NMR (CDCl3, 400MHz) δ: 0.08 (s, 6H), 0.16 (s, 6H), 0.82-0.86 (t, 2H), 1.53-1.60 (m, 2H), 2.90-3.04 (m, 2H), 3.34-3.44 (m , 3H), 3.49-3.59(m, 2H), 5.74-5.86(m, 2H), 6.06-6.12(t, 1H), 7.23-7.26(m, 4H), 7.33-7.36(m, 2H), 7.45-7.47(m, 4H). Experimental Example 2:

[0017] Synthesize siloxane@Ti-POSS graft monomer, the synthesis process is as follows: In the first step, the isobutoxy functional group in isobutoxy heptaphenyl titanium silsesquioxane (also known as Ti-POSS) undergoes a deisobutanol reaction with the silanol functional group obtained by hydrolysis of phenyltrimethoxysilane to generate dihydroxyphenylsiloxy Ti-POSS; In the second step, based on the silanol condensation reaction mechanism, dihydroxyphenylsiloxy Ti-POSS first reacts with vinyldimethylethoxysilane to introduce vinyl functional groups, and then reacts with (3-glycidoxypropyl)dimethylethoxysilane to introduce epoxy functional groups to generate a siloxane@Ti-POSS type grafted monomer; The experimental steps for siloxane@Ti-POSS grafting monomer are as follows: Step 1: 0.38 g of phenyltrimethoxysilane was added to 10 mL of toluene and 2 mL of deionized water, 3 drops of glacial acetic acid were added dropwise, and the mixture was stirred and hydrolyzed at 60 ° C for 1 h. The mixture was cooled to room temperature, and the organic phase was separated and dried with anhydrous magnesium sulfate to obtain a dry hydrolyzate; under dehydration and deoxygenation conditions and an ice bath, the dry hydrolyzate was added dropwise to a 30 mL anhydrous toluene solution in which 2 g of isobutoxy heptaphenyl titanium silsesquioxane (Ti-POSS) was dissolved. After the addition was complete, the reaction was continued under stirring for 0.5 h in an ice bath, the ice bath was removed, the mixture was heated to 25 ° C and reacted for 4 h, and the mixture was concentrated by rotary evaporation under reduced pressure. The solid was precipitated with cold anhydrous acetonitrile under stirring, and the filter cake was filtered and washed with anhydrous acetonitrile to obtain dihydroxyphenylsilyl Ti-POSS; The chemical structure of dihydroxyphenylsilyl Ti-POSS is: ; The hydrogen spectrum characterization results of dihydroxyphenylsilyl Ti-POSS are as follows: 1 H NMR (CDCl3, 400MHz) δ: 6.99 (s, 2H), 7.26-7.33 (m, 24H), 7.50-7.53 (m, 8H), 7.54-7.58 (m, 8H); Step 2: 11.56 g of dihydroxyphenylsiloxy Ti-POSS was added to 80 mL of toluene and 5 mL of deionized water, stirred and dissolved for 10 min, 10 mg of dibutyltin dilaurate and 1.33 g of vinyldimethylethoxysilane were added, and the mixture was stirred and reacted at a constant temperature of 70 ° C for 1.5 h, and then 2.23 g of (3-glycidoxypropyl) dimethylethoxysilane was added, and the mixture was stirred and reacted at a constant temperature of 60 ° C for 3 h. The toluene and small molecular by-products were removed by vacuum rotary evaporation to obtain a siloxane@Ti-POSS type grafted monomer; The chemical structure of the siloxane@Ti-POSS grafting monomer is: ; The hydrogen spectrum characterization results of siloxane@Ti-POSS type grafted monomer are as follows: 1 H NMR (CDCl3, 400MHz) δ: 0.10 (s, 6H), 0.16 (s, 6H), 0.84-0.88 (t, 2H), 1.62-1.69 (m, 2H), 2.98-3.12 (m, 2H), 3.41-3.51 (m, 3H), 3.59-3.72(m, 2H), 5.89-5.99(m, 2H), 6.18-6.23(t, 1H), 7.26-7.33(m, 24H), 7.50-7.52(m, 8H), 7.55-7.57(m, 8H). Experimental Example 3:

[0018] Epoxysiloxane-based LLDPE masterbatch, whose raw material formula is: 84.9wt% linear low-density polyethylene LLDPE resin (brand: DFDA-7042), 0.1wt% dicumyl peroxide and 15wt% siloxane-based grafting monomer; The preparation process of epoxysiloxane type LLDPE masterbatch is as follows: linear low-density polyethylene (LLDPE) resin, dicumyl peroxide and siloxane type grafting monomer are added to a high-speed mixer, stirred and mixed, and then poured into a twin-screw extruder for melt extrusion and granulation to obtain epoxysiloxane type LLDPE masterbatch; Among them, the process parameters of the twin-screw extruder are: screw speed is 40r / min, and the temperatures of zones 1-4 are: 110℃, 125℃, 135℃, and 135℃. Experimental Example 4:

[0019] Epoxysiloxane@Ti-POSS type LLDPE masterbatch, whose raw material formula is: 84.9wt% linear low-density polyethylene LLDPE resin (brand: DFDA-7042), 0.1wt% dicumyl peroxide and 15wt% siloxane@Ti-POSS type grafting monomer; The preparation process of epoxysiloxane@Ti-POSS type LLDPE masterbatch differs from the preparation process of epoxysiloxane type LLDPE masterbatch only in that siloxane@Ti-POSS type grafting monomer is used instead of siloxane type grafting monomer. Example 1:

[0020] PA6-LLDPE film I-1, whose raw material formula is: 90wt% polyamide 6 (PA6) resin and 10wt% epoxysiloxane type LLDPE masterbatch; The preparation process of PA6-LLDPE film I-1 is as follows: polyamide 6 (PA6) resin (brand CM1046) is placed in a vacuum drying oven at 80°C for 24 hours to obtain dried polyamide 6 (PA6) resin; Polyamide 6 (PA6) resin and epoxysiloxane-based LLDPE masterbatch were added to a high-speed mixer, mixed at low speed for 5 minutes and at high speed for 5 minutes, and then added to an extruder for blow molding to obtain a PA6-LLDPE film I-1 with a thickness of 25 μm. Among them, the process parameters of the extruder are: the temperatures of the three zones of the barrel are: 180°C in the fixed conveying zone, 220°C in the melting zone, 220°C in the melt conveying zone, the head temperature is 215°C, and the screw speed is 20r / min. Example 2:

[0021] PA6-LLDPE film I-2, whose raw material formula is: 75wt% polyamide 6 (PA6) resin and 25wt% epoxysiloxane type LLDPE masterbatch; The difference between the preparation process of PA6-LLDPE film I-2 and the preparation process of PA6-LLDPE film I-1 is that the raw material formula of PA6-LLDPE film I-2 is used instead of the raw material formula of PA6-LLDPE film I-1. Example 3:

[0022] PA6-LLDPE film I-3, whose raw material formula is: 70wt% polyamide 6 (PA6) resin and 30wt% epoxysiloxane type LLDPE masterbatch; The difference between the preparation process of PA6-LLDPE film I-3 and the preparation process of PA6-LLDPE film I-1 is that the raw material formula of PA6-LLDPE film I-3 is used instead of the raw material formula of PA6-LLDPE film I-1. Example 4:

[0023] PA6-LLDPE film II-1, whose raw material formula is: 90wt% polyamide 6 (PA6) resin and 10wt% epoxysiloxane@Ti-POSS type LLDPE masterbatch; The difference between the preparation process of PA6-LLDPE film II-1 and the preparation process of PA6-LLDPE film I-1 is that the raw material formula of PA6-LLDPE film II-1 is used instead of the raw material formula of PA6-LLDPE film I-1. Embodiment 5:

[0024] PA6-LLDPE film II-2, whose raw material formula is: 75wt% polyamide 6 (PA6) resin and 25wt% epoxysiloxane@Ti-POSS type LLDPE masterbatch; The difference between the preparation process of PA6-LLDPE film II-2 and the preparation process of PA6-LLDPE film I-1 is that the raw material formula of PA6-LLDPE film II-2 is used instead of the raw material formula of PA6-LLDPE film I-1. Example 6:

[0025] PA6-LLDPE film II-3, whose raw material formula is: 70wt% polyamide 6 (PA6) resin and 30wt% epoxysiloxane@Ti-POSS type LLDPE masterbatch; The difference between the preparation process of PA6-LLDPE film II-3 and the preparation process of PA6-LLDPE film I-1 is that the raw material formula of PA6-LLDPE film II-3 is used instead of the raw material formula of PA6-LLDPE film I-1. Comparative Example 1:

[0026] PA6 film, its raw material formula is: 100wt% polyamide 6 (PA6) resin; The difference between the preparation process of PA6 film and the preparation process of PA6-LLDPE film I-1 is that the raw material formula of PA6 film is used instead of the raw material formula of PA6-LLDPE film I-1. Performance testing:

[0027] 1. Tensile strength: According to GB / T 1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for film and sheeting", a tensile test was conducted using a universal mechanical testing machine. The sample film was cut into strips with a length of 150 mm and a width of 20 mm. The clamp distance was 50 mm and the test speed was 150 mm / min. Puncture strength: According to GB / T 37841-2019 "Test method for puncture resistance of plastic film and sheeting", a sample film with a diameter of 100mm x 100mm was loaded on a tensile testing machine. The thickness of each sample film was measured at 4 points around the periphery and the arithmetic mean was calculated. Five samples were tested in each group at a puncture rate of 100mm / min. Impact strength: According to GB / T 1843-2008 "Determination of Izod Beam Impact Strength of Plastics", the notch type is A, the pendulum impact energy is 5.5J, and the test is repeated three times in parallel, and the average value is taken; 4. Water absorption rate: According to GB / T 1034-2008 "Determination of water absorption of plastics", cut a 60mm x 60mm sample film into an oven and dry it at 80℃ for 24 hours. Take it out and weigh it as m1 (g); then soak it in distilled water at room temperature for 48 hours. Take it out and use filter paper to absorb the surface moisture. Weigh it and record it as m2 (g). Calculate the water absorption rate = (m2-m1) / m1×100%; The above test results are shown in Table 1 below; Table 1 Performance test results of PA6-LLDPE film

[0028] From the above experimental results, we can know that: When the content of silicone LLDPE masterbatch or silicone@Ti-POSS LLDPE masterbatch is reduced to 10wt%, the fracture resistance and puncture resistance of PA6-LLDPE film products are close to those of pure PA6 film products; When the content of silicone LLDPE masterbatch or silicone@Ti-POSS LLDPE masterbatch was increased to 30wt%, the fracture resistance and puncture resistance of PA6-LLDPE film products showed a significant decline compared with pure PA6 film products. Both silicone-based LLDPE masterbatch and silicone@Ti-POSS-based LLDPE masterbatch can significantly improve the impact resistance and water absorption properties of PA6-LLDPE film products; Increasing the content of silicone LLDPE masterbatch or silicone@Ti-POSS LLDPE masterbatch has a significant effect on improving the impact resistance and water absorption properties of PA6-LLDPE film products; Compared with silicone-based LLDPE masterbatch, silicone@Ti-POSS-based LLDPE masterbatch not only shows a more significant improvement in the impact resistance and water absorption properties of PA6-LLDPE film products, but also significantly improves the fracture resistance and puncture resistance of PA6-LLDPE film products.

Claims

1. A method for preparing a new energy battery packaging film, characterized in that: The following steps are involved: Step 1: Based on the silanol condensation reaction mechanism, diphenyldimethoxysilane or dihydroxyphenylsiloxy Ti-POSS is used as a bridging structure, and vinyldimethylethoxysilane and (3-glycidoxypropyl)dimethylethoxysilane provide functional group raw materials to synthesize a siloxane-type grafting monomer containing vinyl and epoxy groups or a siloxane@Ti-POSS-type grafting monomer; Step 2: In a molten state and under the action of a free radical initiator, the grafting monomer is grafted onto the molecular main chain of the LLDPE resin through a free radical graft copolymerization reaction to prepare an epoxy LLDPE masterbatch; Step 3: Based on the epoxy-amine ring-opening reaction mechanism, the epoxy-based LLDPE masterbatch is melt-blended with the PA6 resin to generate a bridged PA6-LLDPE composite masterbatch, and the composite masterbatch is blow-molded to produce a PA6-LLDPE film; Step 4: Use PA6-LLDPE film to replace the PA6 film in the outer layer of the aluminum-plastic film to produce a new energy battery packaging film.

2. The method for preparing a new energy battery packaging film according to claim 1, characterized in that: The preparation method of the siloxane-type grafting monomer is as follows: In the method, diphenyldimethoxysilane is first hydrolyzed in a mixed solvent of toluene and deionized water, and then condensed with the hydrolysis product of vinyldimethylethoxysilane under the catalysis of dibutyltin dilaurate. The condensation reaction is then carried out with the hydrolysis product of (3-glycidoxypropyl)dimethylethoxysilane, and the molar ratio of diphenyldimethoxysilane, vinyldimethylethoxysilane and (3-glycidoxypropyl)dimethylethoxysilane is controlled to be 1:(0.9-0.99):(1.0-1.1) to prepare a siloxane-type grafting monomer.

3. The method for preparing a new energy battery packaging film according to claim 1, characterized in that: The preparation method of the siloxane@Ti-POSS type grafting monomer is: The isobutoxy functional group in isobutoxyheptaphenyltitanium silsesquioxane Ti-POSS reacts with the silanol functional group obtained by hydrolysis of phenyltrimethoxysilane to undergo deisobutanol reaction to generate dihydroxyphenylsiloxy Ti-POSS. In a mixed solvent of toluene and deionized water, under the catalysis of dibutyltin dilaurate, 1 molar equivalent of dihydroxyphenylsiloxy Ti-POSS first undergoes condensation reaction with (0.9-0.99) molar equivalents of the hydrolysis product of vinyldimethylethoxysilane, and then with (1.0-1.1) molar equivalents of the hydrolysis product of (3-glycidoxypropyl)dimethylethoxysilane to form a siloxane@Ti-POSS type grafted monomer.

4. The method for preparing a new energy battery packaging film according to claim 1, characterized in that: The initiator is dicumyl peroxide or tert-butyl perbenzoate.

5. The method for preparing a new energy battery packaging film according to claim 1, characterized in that: The preparation method of the epoxy LLDPE masterbatch is: melt extrusion granulation is carried out through a twin-screw extruder, and the temperatures of zones 1-4 are: 105-115° C., 120-130° C., 130-140° C., and 130-140° C., respectively.

6. The method for preparing a new energy battery packaging film according to claim 1, characterized in that: The PA6-LLDPE film is prepared by blow molding the film through an extruder, wherein the temperatures of the three zones of the extruder barrel are: 170-190° C. in the fixed conveying zone, 210-230° C. in the melting zone, 210-230° C. in the melt conveying zone, and 210-230° C. in the die head.

7. A new energy battery packaging film prepared according to the method according to any one of claims 1 to 6, characterized in that: The new energy battery packaging film is an aluminum-plastic film, the outer layer of which is a PA6-LLDPE film, and the formula of the PA6-LLDPE film is: (70-90) wt% PA6 resin, (10-30) wt% epoxy LLDPE masterbatch; The formula of the epoxy-based LLDPE masterbatch is: (79.85-89.95) wt% LLDPE resin, (0.05-0.15) wt% dicumyl peroxide and (10-20) wt% siloxane or siloxane@Ti-POSS grafting monomer.

8. The new energy battery packaging film according to claim 7, characterized in that: The chemical structural formula of the siloxane-type grafting monomer is: 。 9. The new energy battery packaging film according to claim 7, characterized in that: The chemical structural formula of the siloxane@Ti-POSS type grafting monomer is: 。 10. The new energy battery packaging film according to claim 7, characterized in that: The thickness of the PA6-LLDPE film is 15-30 μm.

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