High performance composite film, manufacturing process and application in lithium battery powder ton bag storage and transportation

Abstract

The application relates to the technical field of lithium battery powder packaging materials, and discloses a high-performance composite film, a manufacturing process and application in lithium battery powder ton bag storage and transportation, in particular to the following: a trialkyl long-chain silane coupling agent or a tetraalkyl long-chain silane coupling agent is synthesized; a surface of graphene rich in a hydroxyl functional group is modified by the silane coupling agent to obtain an organic-inorganic hybrid functional component, and the alkyl long-chain structure on the surface of the functional component can significantly improve the interface bonding condition between the graphene and a polyethylene resin matrix; the organic-inorganic hybrid functional component is used as raw material of an intermediate layer and an inner layer in a three-layer co-extrusion film, and a three-layer co-extrusion blow molding process is used to obtain the high-performance composite film. The high-performance composite film prepared by the application has excellent antistatic performance, barrier performance and mechanical performance, and can be used to manufacture the inner layer of ton bag products.

Description

Technical Field

[0001] This invention relates to the field of lithium battery powder packaging materials technology, and in particular to high-performance composite films, manufacturing processes, and their application in the storage and transportation of lithium battery powder in ton bags. Background Technology

[0002] With the explosive growth of the new energy vehicle and energy storage industries, the demand for lithium batteries has increased exponentially. This has directly driven the large-scale production of upstream lithium battery materials (cathode materials and anode materials). These materials are usually micron-sized powders, which are highly valuable, highly sensitive, and potentially hazardous. Their packaging and transportation face the following severe challenges:

[0003] First, extremely high moisture resistance is required: Positive and negative electrode materials undergo irreversible chemical reactions upon contact with water, leading to product denaturation and failure. For example, moisture can cause lithium dissolution in lithium iron phosphate batteries, causing the ternary material structure to collapse, directly resulting in battery capacity decay, bulging, or even short circuits. Furthermore, the water vapor transmission resistance of traditional woven bags or ordinary PE inner bags cannot meet the requirements for long-term sea transport (high temperature and high humidity environment).

[0004] Second, the need for anti-oxidation: Some materials (such as high-nickel ternary materials) are very sensitive to oxygen. Oxidation will lead to an increase in residual alkali on the surface, which will affect battery performance.

[0005] Third, dust leakage and static electricity hazards: Dust leakage is prone to occur during the filling and transportation of powder, causing not only material and economic losses, but more seriously, the mixture of dust and air may form an explosive environment. At the same time, the friction of powder can generate static electricity of up to tens of thousands of volts, which may cause combustion and explosion accidents after accumulation, posing an extremely dangerous hazard.

[0006] Fourth, insufficient physical properties: Lithium battery materials have high density, and ton bags (also known as flexible container bags, which are usually made of multiple layers of composite materials, including a plastic film as the inner layer and a woven fabric as the main structural layer. Currently, ton bags are mainly used to package lithium battery powder from raw material suppliers to raw material warehouses in battery factories) can bear a weight of more than 500 kg or even 1 ton. During hoisting and transportation, traditional ton bags are prone to breakage due to insufficient strength or poor puncture resistance, resulting in huge losses.

[0007] Fifth, environmental and cost pressures: Traditional packaging is mostly for single use and is difficult to degrade after disposal, which does not conform to the concept of green manufacturing.

[0008] Existing single-layer PE ton bags and aluminum-plastic composite bags cannot perfectly solve all the above problems at the same time. The market urgently needs a new packaging solution that combines ultra-high barrier properties, ultra-high strength, anti-static properties, and cleanliness and environmental friendliness. Summary of the Invention

[0009] This invention independently developed a single PE material co-extruded film with antistatic, high sealing and high strength properties. This film product can be used as a raw material to manufacture the inner layer of ton bag products. The ton bags made from this film can meet the packaging and transportation needs of lithium battery powder.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] High-performance composite thin films, comprising the following layers:

[0012] Outer layer: The formulation consists of 30-50 wt% HDPE and 50-70 wt% LDPE, with a dosage of 20-40 parts by weight;

[0013] Intermediate layer: The formulation consists of 90-97 wt% LDPE and 3-10 wt% organic-inorganic hybrid functional components, with a dosage of 20-40 parts by weight;

[0014] Inner layer: The formulation consists of 30-57wt% m-LLDPE, 40-60wt% LLDPE and 3-10wt% organic-inorganic hybrid functional components, with a dosage of 30-50 parts by weight;

[0015] The organic-inorganic hybrid functional component is prepared by modifying graphene rich in hydroxyl functional groups with a polyalkyl long-chain silane coupling agent, wherein the amount of the coupling agent is 30-80 wt% of the amount of graphene.

[0016] The coupling agent is a trialkyl long-chain silane coupling agent or a tetraalkyl long-chain silane coupling agent;

[0017] The chemical structural formula of the trialkyl long-chain silane coupling agent is:

[0018] ;

[0019] The chemical structural formula of the tetraalkyl long-chain silane coupling agent is:

[0020] ;

[0021] R1 is one of 1-chlorooctadecane, 1-chlorohexadecane, and 1-chlorotetradecane;

[0022] R2 is one of 1-octadecene, 1-nonadene, or 1-eicosene.

[0023] Preferably, the thickness of the high-performance composite film is 80-120 μm.

[0024] Preferably, the graphene has an average thickness of 3.5 nm and a diameter ranging from 5 to 10 μm.

[0025] Preferably, the amount of the trialkyl long-chain silane coupling agent is 30-50 wt% of the amount of graphene.

[0026] Preferably, the amount of the tetraalkyl long-chain silane coupling agent is 50-80 wt% of the amount of graphene.

[0027] The manufacturing process of high-performance composite films includes the following steps:

[0028] Step 1: Synthesize trialkyl long-chain silane coupling agents or tetraalkyl long-chain silane coupling agents, and use these silane coupling agents to modify the surface of graphene rich in hydroxyl functional groups to obtain organic-inorganic hybrid functional components.

[0029] Step 2: Prepare the ingredients according to the formula of the high-performance composite film. Put the raw materials of each film layer into the hoppers of the three screw extruders of the three-layer co-extrusion film blow molding unit, stir and mix them. The molten resin is then gathered at the die head through the distributor, extruded through the die head and blow molded. After cooling and winding, the high-performance composite film is obtained.

[0030] The process parameters for the screw extruder corresponding to the outer layer are set as follows: Zone 1 temperature is 120-140℃, Zone 2 temperature is 140-160℃, Zone 3 temperature is 170-180℃, runner temperature is 165-175℃, and screw speed is 25-35 r / min.

[0031] The process parameters for the screw extruder corresponding to the intermediate layer are set as follows: Zone 1 temperature is 110-130℃, Zone 2 temperature is 130-150℃, Zone 3 temperature is 150-170℃, runner temperature is 150-160℃, and screw speed is 35-45 r / min.

[0032] The process parameters for the screw extruder corresponding to the inner layer are set as follows: Zone 1 temperature is 120-140℃, Zone 2 temperature is 140-160℃, Zone 3 temperature is 160-180℃, runner temperature is 160-170℃, and screw speed is 25-35 r / min.

[0033] Preferably, the preparation method of the trialkyl long-chain silane coupling agent is as follows:

[0034] Based on the substitution reaction mechanism, 1 molar equivalent of octadecylamine reacts with 2 molar equivalents of long straight-chain α-chloro hydrocarbons to prepare trialkyl long-chain amines;

[0035] Among them, the long straight-chain α-chlorohydrocarbon is one of 1-chlorooctadecane, 1-chlorohexadecane, and 1-chlorotetradecane;

[0036] Based on the quaternization reaction mechanism, under the action of a halogen exchange catalyst, the tertiary amine group in 1 molar equivalent of trialkyl long-chain amine reacts with 1 molar equivalent of 3-chloropropyltriethoxysilane to prepare a trialkyl long-chain silane coupling agent.

[0037] Preferably, the preparation method of the tetraalkyl long-chain silane coupling agent is as follows:

[0038] Based on the silanol condensation reaction, using 3-aminopropylmethyldimethoxysilane as the backbone raw material and 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane as the end-capping agent, an aminopropylbenzene-containing siloxane was prepared.

[0039] Dialkyl long-chain diphenyltrisiloxane monomers were prepared by substitution reaction of the amino group in 1 molar equivalent of aminopropylbenzenesiloxane with the chlorine functional group in 2 molar equivalent of long straight-chain α-chloro hydrocarbon.

[0040] Based on the Friedel-Crafts alkylation reaction mechanism, anhydrous aluminum chloride catalyzes the reaction of dialkyl long-chain diphenyltrisiloxane monomers with long straight-chain α-olefins at a molar ratio of 1:2-2.02 to prepare tetraalkyl long-chain diphenyltrisiloxane monomers.

[0041] Among them, the long straight-chain α-olefin is one of 1-octadecene, 1-nonadene, and 1-eicosene;

[0042] In the presence of a halogen exchange catalyst, a tetraalkyl long-chain silane coupling agent is prepared by quaternization of the tertiary amine group in 1 molar equivalent of tetraalkyl long-chain diphenyltrisiloxane monomer with the chlorine functional group in 1 molar equivalent of 3-chloropropyltriethoxysilane.

[0043] Preferably, the halogen exchange catalyst is one of potassium iodide and sodium iodide.

[0044] Preferably, the high-performance composite film is used to manufacture the inner layer of ton bag products.

[0045] The beneficial effects of this invention are as follows:

[0046] Using octadecylamine as the backbone raw material, the primary amine functional group in its structure first undergoes a substitution reaction with the chlorine functional group in 1-chlorooctadecane, and then undergoes a quaternization reaction with the chlorine functional group in 3-chloropropyltriethoxysilane to prepare a trialkyl long-chain silane coupling agent.

[0047] Based on the silanol condensation reaction, using 3-aminopropylmethyldimethoxysilane as the backbone raw material and 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane as the end-capping agent, an aminopropylbenzene-containing siloxane was prepared.

[0048] The primary amine functional group of aminopropylbenzenesiloxane undergoes a substitution reaction with the chlorine functional group in 1-chlorooctadecane, followed by a Friedel-Crafts alkylation reaction using the benzene ring in its structure with the alkenyl functional group in 1-octadecene, and finally a quaternization reaction using the tertiary amine group in its structure with the chlorine functional group in 3-chloropropyltriethoxysilane to prepare a tetraalkyl long-chain silane coupling agent.

[0049] The above-mentioned silane coupling agent was modified on the surface of graphene with excellent antistatic and barrier properties to prepare a high-performance organic-inorganic hybrid functional component. The long alkyl chain structure on the surface of the functional component can significantly improve the interfacial bonding between graphene and polyethylene resin matrix.

[0050] High-performance composite films were prepared by using organic-inorganic hybrid functional components as modifiers for polyethylene resin and employing a three-layer co-extrusion blow molding process.

[0051] Experimental results demonstrate that the high-performance composite film prepared by this invention exhibits superior antistatic, barrier, and mechanical properties. Detailed Implementation Example 1:

[0052] The synthesis mechanism of trialkyl long-chain silane coupling agents is as follows:

[0053] Step S1: Tri(octadecyl)amine is generated by the substitution reaction between the amino group in octadecylamine and the chlorine functional group in 1-chlorooctadecane.

[0054] Step S2: Quaternization reaction occurs between the tertiary amine group in tri(octadecyl)amine and the chlorine functional group in 3-chloropropyltriethoxysilane to generate a trialkyl long-chain silane coupling agent;

[0055] The specific experimental steps for trialkyl long-chain silane coupling agents are as follows:

[0056] Step 1: Add 2.7g of octadecylamine and 20mL of anhydrous ethanol to a 250mL three-necked flask equipped with a stirrer, reflux condenser and constant pressure dropping funnel, stir mechanically until homogeneous, add 40mL of chloroform solution containing 5.8g of 1-chlorooctadecane dropwise over 2h, then add 30% sodium hydroxide solution, maintain the pH of the reaction system at 11, stir and reflux at 80℃ for 1h, after the reaction is complete, remove the solvent by vacuum distillation, wash, and vacuum dry at 50℃ for 8h to obtain tri(octadecyl)amine;

[0057] Step 2: Add 7.75g of tri(octadecyl)amine and 2.41g of 3-chloropropyltriethoxysilane to 80mL of anhydrous toluene, stir mechanically to dissolve, add 0.08g of potassium iodide, raise the system temperature to 70℃, stir and react for 30h. After the reaction is complete, remove the solvent by rotary evaporation, and dry in a vacuum drying oven at 60℃ for 5h to obtain the trialkyl long-chain silane coupling agent.

[0058] The chemical structural formula of the trialkyl long-chain silane coupling agent is:

[0059] ;

[0060] The 1H NMR characterization of the trialkyl long-chain silane coupling agent is as follows:

[0061] 1 H NMR (CDCl3, 400MHz) δ: 0.88-0.90 (t, 9H), 0.97-1.01 (t, 2H), 1.13-1.16 (t, 9H), 1.27-1. 38(m, 90H), 1.73-1.84(m, 8H), 3.38-3.41(t, 6H), 3.58-3.62(t, 2H), 3.77-3.82(m, 6H). Example 2:

[0062] The synthetic mechanism for tetraalkyl long-chain silane coupling agents is as follows:

[0063] Step S1: Based on the hydrolysis-condensation reaction mechanism, 3-aminopropylmethyldimethoxysilane and 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane are used as raw materials to generate aminopropylphenylsiloxane.

[0064] Step S2: The amino group in aminopropylbenzenesiloxane undergoes a substitution reaction with the chlorine functional group in 1-chlorooctadecane to generate a dioctadecyldiphenyltrisiloxane monomer;

[0065] Step 3 S3: Based on the Friedel-Crafts alkylation reaction mechanism, tetra(octadecyl)diphenyltrisiloxane monomer and 1-octadecene are used as raw materials to generate tetra(octadecyl)diphenyltrisiloxane monomer;

[0066] Step S4: Quaternization reaction occurs between the tertiary amine group in the tetra(octadecyl)diphenyltrisiloxane monomer and the chlorine functional group in 3-chloropropyltriethoxysilane to generate a tetraalkyl long-chain silane coupling agent.

[0067] The specific experimental steps for tetraalkyl long-chain silane coupling agents are as follows:

[0068] Step 1: Under nitrogen protection, 1.63 g of 3-aminopropylmethyldimethoxysilane, 14.33 g of 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane, and 100 mL of benzene were added to a 250 mL three-necked flask equipped with a thermometer and a reflux condenser. Then, 0.03 g of tetramethylammonium hydroxide was added dropwise. The temperature was raised to 90 °C and refluxed for 3 h. After the reaction was completed, the mixture was distilled under reduced pressure and cooled to room temperature to obtain aminopropylphenylsiloxane.

[0069] Step 2: Add 4.04 g of aminopropylbenzenesiloxane and 5.78 g of 1-chlorooctadecane to 60 mL of toluene, stir well, add 30% sodium hydroxide solution to adjust the pH of the system to 11, raise the system temperature to 80 °C, stir and reflux for 1 h, remove the solvent by rotary evaporation, and dry under vacuum at 50 °C to constant weight to obtain bis(octadecyl)diphenyltrisiloxane monomer;

[0070] Step 3: Add 4.55g of dried dioctadecyl diphenyltrisiloxane monomer and 30mL of anhydrous toluene to a dry 250mL three-necked flask, add 0.2g of anhydrous aluminum chloride catalyst, stir mechanically until homogeneous, raise the temperature to 80℃, add 2.53g of 1-octadecene dropwise over 0.5h, and react at a constant temperature for 6h. After the reaction is complete, remove the solvent by rotary evaporation, and dry in a vacuum drying oven at 60℃ for 5h to obtain tetra(octadecyl)diphenyltrisiloxane monomer.

[0071] Step 4: Add 7.1g of tetra(octadecyl)diphenyltrisiloxane monomer and 1.2g of 3-chloropropyltriethoxysilane to 50mL of toluene, stir magnetically until homogeneous, add 0.05g of potassium iodide, raise the temperature to 100℃, stir and react for 30h, remove the solvent by rotary evaporation, and dry under vacuum at 60℃ to constant weight to obtain the tetraalkyl long-chain silane coupling agent;

[0072] The chemical structural formula of the tetraalkyl long-chain silane coupling agent is:

[0073] ;

[0074] The proton NMR spectrum characterization of the tetraalkyl long-chain silane coupling agent is as follows:

[0075] 1H NMR (CDCl3, 400MHz) δ: 0.05 (s, 3H), 0.34 (s, 12H), 0.88-0.90 (t, 12H), 0.98 -1.02(t, 4H), 1.13-1.16(t, 9H), 1.27-1.38(m, 120H), 1.52-1.58(m, 4H), 1 .68-1.84(m, 8H), 2.61-2.64(t, 4H), 3.33-3.37(t, 4H), 3.45-3.60(m, 2H), 3.65-3.69(t, 2H), 3.77-3.82(m, 6H), 7.01-7.03(d, 4H), 7.36-7.38(d, 4H). Example 3:

[0076] (1) Preparation of organic-inorganic hybrid functional component I: 100 mg of graphene powder (average thickness of 3.5 nm and diameter of 5 μm) was added to a mixed solution of 10 mL of distilled water and 7.5 mL of anhydrous ethanol and ultrasonically treated for 1 h. Then, 2.5 mL of anhydrous ethanol solution containing 46 mg of trialkyl long-chain silane coupling agent was added under stirring. After the addition was completed, the system temperature was raised to 60 °C and the reaction was carried out for 24 h. After the reaction was completed, the mixture was filtered, washed, and vacuum dried at 50 °C to constant weight to obtain organic-inorganic hybrid functional component I.

[0077] (2) Prepare organic-inorganic hybrid functional component II, which differs from organic-inorganic hybrid functional component I only in that 75 mg of tetraalkyl long-chain silane coupling agent is used instead of 46 mg of trialkyl long-chain silane coupling agent. Example 4:

[0078] (1) Preparation of high-performance composite thin film I-1, including the following steps:

[0079] Step 1: Set the high-performance composite thin film I-1 as a three-layer membrane structure. The formulation and dosage of each membrane layer are as follows:

[0080] Outer layer: The formula consists of 40 wt% high-density polyethylene resin (HDPE) and 60 wt% low-density polyethylene resin (LDPE), with a dosage of 30 parts by weight.

[0081] Intermediate layer: The formulation consists of 93 wt% low-density polyethylene resin (LDPE) and 7 wt% organic-inorganic hybrid functional component I, with a dosage of 30 parts by weight;

[0082] Inner layer: The formula consists of 43 wt% metallocene linear low-density polyethylene resin m-LLDPE, 50 wt% linear low-density polyethylene resin LLDPE and 7 wt% organic-inorganic hybrid functional component I, with a dosage of 40 parts by weight.

[0083] Step 2: The raw materials of each film layer in Step 1 are respectively fed into the hoppers of the three screw extruders of the three-layer co-extrusion film blow molding unit. After stirring and mixing, the molten resin is gathered at the die head through the distributor, extruded through the die head and blow molded, and then cooled and wound up to obtain a high-performance composite film I-1 with a thickness of 100μm.

[0084] The process parameters for the screw extruder corresponding to the outer layer are set as follows: zone 1 temperature is 130℃, zone 2 temperature is 150℃, zone 3 temperature is 175℃, flow channel temperature is 170℃, and screw speed is 30r / min.

[0085] The process parameters for the screw extruder corresponding to the intermediate layer are set as follows: Zone 1 temperature is 120℃, Zone 2 temperature is 140℃, Zone 3 temperature is 160℃, runner temperature is 155℃, and screw speed is 40r / min.

[0086] The process parameters for the screw extruder corresponding to the inner layer are set as follows: Zone 1 temperature is 130℃, Zone 2 temperature is 150℃, Zone 3 temperature is 170℃, runner temperature is 165℃, and screw speed is 30r / min.

[0087] Among them, the grade of high-density polyethylene resin HDPE is MH602; the grade of low-density polyethylene resin LDPE is 2426H; the grade of metallocene linear low-density polyethylene resin m-LLDPE is SP1520; and the grade of linear low-density polyethylene resin LLDPE is 7042.

[0088] (2) Prepare high-performance composite film II-1, which differs from high-performance composite film I-1 only in that: organic-inorganic hybrid functional component II is used instead of organic-inorganic hybrid functional component I.

[0089] (3) Prepare high-performance composite film I-2, which differs from high-performance composite film I-1 only in that:

[0090] Intermediate layer: The formulation consists of 97 wt% low-density polyethylene resin (LDPE) and 3 wt% organic-inorganic hybrid functional component I, with a dosage of 30 parts by weight;

[0091] Inner layer: The formulation consists of 47 wt% metallocene linear low-density polyethylene resin m-LLDPE, 50 wt% linear low-density polyethylene resin LLDPE, and 3 wt% organic-inorganic hybrid functional component I, in a dosage of 40 parts by weight.

[0092] (4) Preparation of high-performance composite film I-3, which differs from high-performance composite film I-1 only in that:

[0093] Intermediate layer: The formulation consists of 90 wt% low-density polyethylene resin (LDPE) and 10 wt% organic-inorganic hybrid functional component I, with a dosage of 30 parts by weight;

[0094] Inner layer: The formula consists of 40 wt% metallocene linear low-density polyethylene resin m-LLDPE, 50 wt% linear low-density polyethylene resin LLDPE, and 10 wt% organic-inorganic hybrid functional component I, with a dosage of 40 parts by weight.

[0095] (5) Preparation of high-performance composite film II-2, which differs from high-performance composite film I-1 only in that:

[0096] Intermediate layer: The formulation consists of 97wt% low-density polyethylene resin (LDPE) and 3wt% organic-inorganic hybrid functional component II, with a dosage of 30 parts by weight.

[0097] Inner layer: The formulation consists of 47 wt% metallocene linear low-density polyethylene resin m-LLDPE, 50 wt% linear low-density polyethylene resin LLDPE, and 3 wt% organic-inorganic hybrid functional component II, in a dosage of 40 parts by weight.

[0098] (6) Preparation of high-performance composite film II-3, which differs from high-performance composite film I-1 only in that:

[0099] Intermediate layer: The formulation consists of 90 wt% low-density polyethylene resin (LDPE) and 10 wt% organic-inorganic hybrid functional component II, with a dosage of 30 parts by weight.

[0100] Inner layer: The formula consists of 40 wt% metallocene linear low-density polyethylene resin m-LLDPE, 50 wt% linear low-density polyethylene resin LLDPE, and 10 wt% organic-inorganic hybrid functional component II, with a dosage of 40 parts by weight.

[0101] Performance testing:

[0102] I. Antistatic performance: The surface resistance of the high-performance composite film was tested according to GB / T 31838.3-2019 "Dielectric and resistive properties of solid insulating materials - Part 3: Resistive properties (DC method) - Surface resistance and surface resistivity". The size of the high-performance composite film was 100mm×100mm. Electrode device C1 was used and the test voltage was set to 100V.

[0103] II. Barrier Properties: The prepared high-performance composite film was fabricated to have an area of ​​40 cm². 2 Circular sample;

[0104] According to GB / T 1038.1-2022 "Test methods for gas permeability of plastic films and sheets - Part 1: Differential pressure method", the oxygen barrier properties of the sample were tested and the oxygen permeation of the sample was recorded.

[0105] The water resistance of the samples was tested according to GB / T 1037-2021 "Determination of Water Vapor Permeability of Plastic Films and Sheets - Cup Method for Weight Gain and Loss". The water vapor permeation of the samples was recorded. The test conditions were 23℃ and 90% relative humidity.

[0106] III. Tensile Strength: The longitudinal tensile strength of the high-performance composite film was tested according to GB / T 1040.3-2018 "Test of tensile properties of plastics - Part 3: Test conditions for films and sheets". The tensile test was carried out using a universal testing machine. The size of the high-performance composite film was 150mm × 20mm, the clamping distance was 50mm, and the test speed was 150mm / min.

[0107] The test results are shown in Table 1 below;

[0108] Table 1 Performance test results of high-performance composite films

[0109]

[0110] As can be seen from the experimental results in Table 1, the high-performance composite film prepared by this invention has achieved significant improvements in antistatic properties, barrier properties, and mechanical properties, which are beneficial technical effects.

Claims

1. A high performance composite film, characterized by, Each layer comprises the following settings: Outer layer: formula of 30-50wt% HDPE and 50-70wt% LDPE, dosage of 20-40 parts by weight; Middle layer: formula of 90-97wt% LDPE and 3-10wt% organic-inorganic hybrid functional components, dosage of 20-40 parts by weight; Inner layer: formula of 30-57wt% m-LLDPE, 40-60wt% LLDPE and 3-10wt% organic-inorganic hybrid functional components, dosage of 30-50 parts by weight; The organic-inorganic hybrid functional components are obtained by modifying the graphene rich in hydroxyl functional groups with a multi-alkyl long-chain silane coupling agent, and the dosage of the coupling agent is 30-80wt% of the dosage of the graphene; The coupling agent is a trialkyl long-chain silane coupling agent or a tetraalkyl long-chain silane coupling agent; The chemical structural formula of the trialkyl long-chain silane coupling agent is: ； The chemical structural formula of the tetraalkyl long-chain silane coupling agent is: ； R1 is one of 1-chlorooctadecane, 1-chlorohexadecane, and 1-chlorotetradecane; R2 is one of 1-octadecene, 1-nonadecene, and 1-eicosene.

2. The high performance composite film of claim 1, wherein, The thickness of the high-performance composite film is 80-120μm.

3. The high performance composite film of claim 1, wherein The average thickness of the graphene is 3.5nm, and the diameter range is 5-10μm.

4. The high performance composite film of claim 1, wherein The dosage of the trialkyl long-chain silane coupling agent is 30-50wt% of the dosage of the graphene.

5. The high performance composite film of claim 1, wherein, The dosage of the tetraalkyl long-chain silane coupling agent is 50-80wt% of the dosage of the graphene.

6. A manufacturing process for preparing the high performance composite film of claim 1, characterized by, The method comprises the following steps: Step one: synthesize a trialkyl long-chain silane coupling agent or a tetraalkyl long-chain silane coupling agent, and modify the surface of the graphene rich in hydroxyl functional groups with the silane coupling agent to obtain organic-inorganic hybrid functional components; Step two: according to the formula of the high-performance composite film, the raw materials of each film layer are respectively put into the hoppers of the three screw extruders of a three-layer co-extrusion film blowing machine, and after stirring and mixing, the molten resin is converged at the die head through a flow divider, and then extruded and blown into a film, and then cooled and wound to obtain a high-performance composite film; The process parameters of the screw extruder corresponding to the outer layer are set as follows: the temperature of zone one is 120-140℃, the temperature of zone two is 140-160℃, the temperature of zone three is 170-180℃, the temperature of the flow channel is 165-175℃, and the screw rotation speed is 25-35r / min; The process parameters of the screw extruder corresponding to the middle layer are set as follows: the temperature of zone one is 110-130℃, the temperature of zone two is 130-150℃, the temperature of zone three is 150-170℃, the temperature of the flow channel is 150-160℃, and the screw rotation speed is 35-45r / min; The process parameters of the screw extruder corresponding to the inner layer are set as follows: the temperature of zone one is 120-140℃, the temperature of zone two is 140-160℃, the temperature of zone three is 160-180℃, the temperature of the flow channel is 160-170℃, and the screw rotation speed is 25-35r / min.

7. The manufacturing process of high performance composite film according to claim 6, wherein, The preparation method of the trialkyl long-chain silane coupling agent is: Based on the substitution reaction mechanism, 1 mole equivalent of octadecylamine reacts with 2 mole equivalents of long straight chain alpha-chlorohydrocarbon to produce a long-chain trialkyl amine; Among them, the long straight chain alpha-chlorohydrocarbon is one of 1-chlorooctadecane, 1-chlorohexadecane and 1-chlorotetradecane; Based on the quaternization reaction mechanism, under the action of halogen exchange type catalyst, 1 mole equivalent of tertiary amine group in the long-chain trialkyl amine reacts with 1 mole equivalent of 3-chloropropyl triethoxysilane to produce a long-chain trialkyl silane coupling agent.

8. The manufacturing process of high performance composite film according to claim 6, wherein, The preparation method of the long-chain tetraalkyl silane coupling agent is: Based on the silicon hydroxyl condensation reaction, 3-aminopropyl methyl dimethoxysilane is used as the skeleton raw material, and 1,1,3,3-tetramethyl-1,3-diphenyl disiloxane is used as the end-capping agent to produce an aminopropyl phenyl-containing siloxane; Through substitution reaction between 1 mole equivalent of amino group in the aminopropyl phenyl-containing siloxane and 2 mole equivalents of chlorine functional groups in the long straight chain alpha-chlorohydrocarbon, a long-chain dialkyl diphenyl trisiloxane monomer is produced; Based on the Friedel-Crafts alkylation reaction mechanism, anhydrous aluminum chloride catalyzes the reaction between the long-chain dialkyl diphenyl trisiloxane monomer and the long straight chain alpha-olefin according to the molar equivalent ratio of 1:2-2.02 to produce a long-chain tetraalkyl diphenyl trisiloxane monomer; Among them, the long straight chain alpha-olefin is one of 1-octadecene, 1-nonadecene and 1-eicosene; Under the action of halogen exchange type catalyst, through quaternization reaction between 1 mole equivalent of tertiary amine group in the long-chain tetraalkyl diphenyl trisiloxane monomer and 1 mole equivalent of chlorine functional groups in the 3-chloropropyl triethoxysilane, a long-chain tetraalkyl silane coupling agent is produced.

9. The manufacturing process of a high performance composite film according to claim 7 or 8, characterized in that, The halogen exchange type catalyst is one of potassium iodide and sodium iodide.

10. Use of a high performance composite film according to any one of claims 1 to 5, characterized in that, The high-performance composite film is used to manufacture the inner layer of lithium battery powder ton bag products.

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