CN113437436B - High-flexibility lithium ion battery film and preparation method thereof - Google Patents

High-flexibility lithium ion battery film and preparation method thereof Download PDF

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CN113437436B
CN113437436B CN202110725726.1A CN202110725726A CN113437436B CN 113437436 B CN113437436 B CN 113437436B CN 202110725726 A CN202110725726 A CN 202110725726A CN 113437436 B CN113437436 B CN 113437436B
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temperature
stretching
transverse stretching
film
agent
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CN113437436A (en
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赵洪亮
刘涛涛
陈朝晖
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Jiangsu Housheng New Energy Technology Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/44—Fibrous material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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Abstract

The invention discloses a high-flexibility lithium ion battery film and a preparation method thereof, wherein the battery film is prepared from the following raw materials, by weight, 67% -74% of a pore-forming agent, 25% -30% of ultrahigh molecular weight polyethylene, 0.1% -0.2% of polycarbonate, 0.1% -2% of random copolymerization polypropylene, 0.1% -0.2% of chlorinated polyethylene, 0.1% -0.2% of polymethyl methacrylate, 0.1% -0.2% of a dispersing agent, 0.1% -0.2% of reinforcing fibers, 0.1% -0.2% of colloidal silica, 0.1% -0.2% of a compatilizer, and 0.1% -0.2% of a crosslinking agent, wherein the dispersing agent is prepared from polyvinylpyrrolidone and methylnaphthalene. When the ultrahigh molecular weight polyethylene and the white oil are mixed, polycarbonate, polypropylene random copolymer, chlorinated polyethylene, polymethyl methacrylate, polyvinylpyrrolidone, reinforcing fiber, colloidal silica, a compatilizer and a crosslinking agent are added at the same time for mixing, and the mixture is longitudinally and transversely stretched to finally obtain the effect of the lithium battery diaphragm with obvious crosslinking, a complex three-dimensional space structure and a high-tortuosity pore structure.

Description

High-flexibility lithium ion battery film and preparation method thereof
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a high-flexibility lithium ion battery thin film and a preparation method thereof.
Background
The lithium ion battery is composed of four parts, namely a positive electrode material, a negative electrode material, a diaphragm and electrolyte. The diaphragm is an important component of the lithium battery, plays a role in separating the positive electrode and the negative electrode of the battery and preventing the short circuit caused by the contact of the two electrodes, and has a function of enabling electrolyte ions to freely pass between the positive electrode and the negative electrode, and prevents the current conduction in the battery through a 'closed-cell function' when the battery is overheated. The tortuosity of the micropores of the diaphragm is too small, pores of the diaphragm can form a parallel net post channel close to an ideal state, the puncture strength of the diaphragm can be greatly reduced, the risk of short circuit caused by contact of a positive electrode and a negative electrode is increased, and meanwhile, the safety performance of the lithium battery is reduced because the diaphragm is difficult to fuse and close completely when the temperature is too high and the micropores are required to be completely fused, so that the high-tortuosity lithium ion battery film and the preparation method thereof are particularly important.
Disclosure of Invention
The invention aims to provide a high-flexibility lithium ion battery thin film and a preparation method thereof, so as to solve the problems in the background technology.
In order to solve the technical problems, the invention provides the following technical scheme: a high-flexibility lithium ion battery film is prepared from the following raw materials, by weight, 67% -74% of a pore-foaming agent, 25% -30% of ultrahigh molecular weight polyethylene, 0.1% -0.2% of polycarbonate, 0.1% -2% of random copolymer polypropylene, 0.1% -0.2% of chlorinated polyethylene, 0.1% -0.2% of polymethyl methacrylate, 0.1% -0.2% of a dispersing agent, 0.1% -0.2% of reinforcing fibers, 0.1% -0.2% of colloidal silica, 0.1% -0.2% of a compatilizer and 0.1% -0.2% of a crosslinking agent.
Further, the dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
Further, the dispersant also comprises methylnaphthalene.
Further, the polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
Further, the catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fiber, colloidal silicon dioxide, a compatilizer and a crosslinking agent, stirring uniformly, adding a pore-foaming agent, stirring uniformly, and extruding the pore-foaming agent;
(2) longitudinal stretching: longitudinally stretching the extruded sheet;
(3) primary transverse stretching: transversely stretching the film after longitudinal stretching;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through the extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out;
(5) heat setting: and (4) performing heat setting treatment on the film subjected to the secondary transverse stretching.
Further, the concrete steps are as follows,
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fiber, colloidal silicon dioxide, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 20-30rpm, the extrusion temperature is 200-250 ℃, and the temperature of a casting roll is 10-22 ℃;
the extrusion temperature is limited to 200 ℃ and 250 ℃ because the structure formed by the corresponding cast sheet becomes more compact and the pore size of the diaphragm is reduced as the melt extrusion temperature is increased. As the temperature of the casting roll is reduced, the more dense the sheet crystal clusters of the casting sheet are, and the smaller the aperture of the corresponding diaphragm is.
(2) Longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 90-110 ℃, and the stretching ratio of the longitudinal stretching is 5-9;
this application has been injectd longitudinal stretching temperature and tensile ratio, and the reason lies in keeping relatively lower temperature and tensile ratio, can guarantee that the molecular chain activity can be lower, and the crystal orientation is lower, and then under the effect of longitudinal stretching power for pore-forming structure is complicated relatively.
(3) Primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 100-110 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through the extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the secondary transverse stretching temperature is 120-130 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80-100 ℃.
Further, the preparation steps of the dispersant are as follows,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, adding copper acetylide, heating at 95-100 deg.C for 2-3h under 1-1.5MPa to obtain product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating at the temperature of 130-;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at 50-60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 70-75 ℃, adding sulfuric acid and sulfur trioxide, raising the temperature, keeping the temperature at 135-150 ℃, maintaining the temperature for 3-4h, lowering the temperature at 120-125 ℃, adding deionized water for hydrolysis, continuing to lower the temperature at 75-85 ℃, adding recovered formaldehyde, raising the temperature at 105-110 ℃, and maintaining the temperature for 4-5h to obtain a product C;
s3, preparation of a dispersing agent:
and mixing the obtained product polyvinylpyrrolidone with the product C to obtain the dispersing agent.
Contain self-made polyvinylpyrrolidone in the dispersant that this application added, this application passes through formaldehyde and acetylene through a series of reactions such as addition, dehydrogenation, ammonolysis, obtains polyvinylpyrrolidone, and the polyvinylpyrrolidone who obtains is a macromolecular surfactant agent, has the effect of apparent dispersant for the crystal structure of polymer refines more, thereby forms more complicated compact microporous structure, and can also improve the wettability of diaphragm electrolyte.
This application uses formaldehyde and acetylene to react, and in order to guarantee product quality, this application is injectd the addition of raw materials, and the mass ratio of injecing to add formaldehyde and acetylene is 3.5-4.7: 1, limiting the mass ratio of the introduced ammonia gas to the acetylene to be 0.78-0.85:1, further ensuring that the acetylene can be completely converted into a product, and further ensuring the product quality. However, the residual formaldehyde is added, so that the formaldehyde has high reducibility, certain carcinogenicity and dangerousness, and can be oxidized into formic acid in an oxide layer in the air, so that the production safety risk is increased due to the residual formaldehyde, the qualification rate of products is reduced, and the formaldehyde needs to be correspondingly treated.
This application is handled formaldehyde, methylnaphthalene has been added, methylnaphthalene adds the formaldehyde of retrieving after the sulfonation and reacts, can generate anion surface active agent MF, the surfactant MF who obtains uses as the dispersant, use with the cooperation of polyvinylpyrrolidone, can make the crystal structure of polymer more refine, and then can form more complicated fine and close microporous structure, and the surfactant MF who obtains has higher heat resistance, it is very stable under high temperature state, consequently, can avoid taking place at the phenomenon of rupture of membranes, the surfactant MF who adds still has certain hydrophilicity, can improve the affinity of product diaphragm and electrolyte. It should be noted that the surfactant MF prepared by the present application cannot be used with a cationic surfactant, and therefore, when the dispersant is selected, polyvinylpyrrolidone is purposefully selected to be used in combination with the surfactant MF, so that the dispersing ability is enhanced, and the hydrophilic performance of the membrane is improved.
Further, in the step S1(1), the mass ratio of the formaldehyde to the acetylene added is 3.5-4.7: 1.
further, the mass ratio of the ammonia gas and the acetylene introduced in the step S1(2) is 0.78-0.85: 1.
Further, in step S2, the mass ratio of the methylnaphthalene to the acetylene is 90-120: 1.
Compared with the prior art, the invention has the following beneficial effects: when the ultrahigh molecular weight polyethylene and the white oil are mixed, polycarbonate, polypropylene random copolymer, chlorinated polyethylene, polymethyl methacrylate, polyvinylpyrrolidone, reinforcing fiber, colloidal silica, a compatilizer and a crosslinking agent are added at the same time for mixing, and the mixture is longitudinally and transversely stretched to finally obtain the lithium battery diaphragm with obvious crosslinking, a complex three-dimensional space structure and a high-tortuosity pore structure.
The application aims to select and use the high molecular weight polyethylene when selecting the polyethylene, and controls the molecular weight of the high molecular weight polyethylene to be 2000000-4000000, because the higher the molecular weight of the polyethylene is, the weaker the molecular chain movement capability is, the more obvious the molecular chain entanglement is, and the pore structure is convenient to be complicated when the pore is formed in the subsequent process.
Polycarbonate has been added to this application, and polycarbonate is a non-crystalline type thermoplastic, because its plastics polymer chain is arranged in disorder and is entangled, does not form orderly arrangement structure, leads to it not have crystal nucleus and crystalline grain growth process in the solidification process, mixes the back with the polyethylene of crystallinity, is favorable to going on of spinodal line phase separation, finally forms the three-dimensional porous structure that communicates that has the fibrous skeleton of nanometer. Meanwhile, the continuous vesicle structure form further improves the tortuosity of the microporous structure.
The random copolymerization polypropylene is added, wherein the mass fraction of the ethylene molecules is generally 1-7%, and the ethylene molecules are randomly inserted among the propylene molecules on a polymer chain, so that the order of the molecules is reduced. Ethylene enters the main chain in both single and multiple molecular forms, and when the ratio of the two is very different, the crystallinity of the copolymer is significantly reduced. The comonomer in the copolymerization polypropylene is randomly distributed on the molecular chain of the isotactic polypropylene, the regularity of the homopolymerization polypropylene chain is damaged, and the particles in the system are connected together to form a large intestine shape, so that the tortuosity of the micropore structure is improved.
Chlorinated polyethylene is added in the method, and due to the introduction of chlorine atoms with polarity, the regularity of a polyethylene molecular structure is destroyed, the distance between chain segments is increased, the original high-crystallization aggregation state is changed into a loose amorphous state, and a mixture with low orientation degree is formed when the polymer is mixed and melted, so that a microporous structure with an irregular shape is obtained, and the tortuosity of micropores is improved.
Polymethyl methacrylate is further added, and because the carbon atoms in the polymethyl methacrylate are connected with methyl and methyl ester groups, the methyl and methyl ester groups destroy the space regularity of a molecular chain, the macromolecular chain is of an atactic three-dimensional structure and is a typical amorphous polymer, and the atactic high-tortuosity microporous structure can be conveniently obtained after the amorphous polymer is mixed with the main material.
The application also adds the reinforcing fiber, mixes with a proper amount of colloidal silicon dioxide and other substances, the mixture has low enough beating degree, and is helpful for forming an irregular three-dimensional space network structure, and the added maleic anhydride grafting compatilizer leads the material to have high polarity and reactivity by introducing strong polar reactive groups. The application also adds vinyl silane cross-linking agent, which can generate chemical bond between linear molecules, so that the linear molecules are connected together to form a more complex network structure, thereby improving the tortuosity of micropores.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
A high-flexibility lithium ion battery film is prepared from 67 wt% of pore-foaming agent, 29.4 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 2 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of reinforcing fiber, 0.2 wt% of colloidal silica, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 30rpm, the extrusion temperature is 200 ℃, and the temperature of a casting roll is 20 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 105 ℃, and the stretching ratio of the longitudinal stretching is 7;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 120 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the secondary transverse stretching temperature is 130 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 100 ℃.
Example 2
The high-flexibility lithium ion battery film is prepared from the following raw materials, by weight, 70% of pore-foaming agent, 26.5% of ultrahigh molecular weight polyethylene, 0.2% of polycarbonate, 2% of random copolymerization polypropylene, 0.2% of chlorinated polyethylene, 0.2% of polymethyl methacrylate, 0.2% of dispersing agent, 0.2% of reinforcing fiber, 0.2% of colloidal silica, 0.2% of compatilizer and 0.2% of crosslinking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 30rpm, the extrusion temperature is 200 ℃, and the temperature of a casting roll is 20 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 105 ℃, and the stretching ratio of the longitudinal stretching is 7;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 120 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the secondary transverse stretching temperature is 130 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 100 ℃.
Example 3
A high-flexibility lithium ion battery film is prepared from the following raw materials, by weight, 74% of pore-foaming agent, 25% of ultrahigh molecular weight polyethylene, 0.1% of polycarbonate, 0.1% of random copolymerization polypropylene, 0.1% of chlorinated polyethylene, 0.1% of polymethyl methacrylate, 0.1% of dispersing agent, 0.1% of reinforcing fiber, 0.2% of colloidal silica, 0.1% of compatilizer and 0.1% of crosslinking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following specific steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 3.5: 1, adding acetylene copper, heating at 95 ℃, reacting for 2 hours under the pressure of 1MPa to obtain a product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 130 ℃, adding copper powder, continuously raising the temperature to 220 ℃, maintaining for 2 hours, introducing ammonia gas and inert gas, reacting for 2 hours, adding potassium hydroxide, and beginning to cool to 130 ℃ to obtain a product B, wherein the mass ratio of the introduced ammonia gas to acetylene is 0.78: 1;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at 50 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 70 ℃, adding sulfuric acid and sulfur trioxide at a mass ratio of the added methylnaphthalene to acetylene of 90:1, heating to 135 ℃, maintaining for 3 hours, cooling to 120 ℃, adding deionized water for hydrolysis, continuously cooling to 75 ℃, adding recovered formaldehyde, heating to 105 ℃, and maintaining for 4 hours to obtain a product C;
s3, preparation of a dispersing agent:
mixing the obtained product polyvinylpyrrolidone with the product C to obtain a dispersing agent;
s4, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 30rpm, the extrusion temperature is 200 ℃, and the temperature of a casting roll is 20 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 105 ℃, and the stretching ratio of the longitudinal stretching is 7;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 120 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the secondary transverse stretching temperature is 130 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 100 ℃.
Example 4
A high-flexibility lithium ion battery film is prepared from 67 wt% of pore-foaming agent, 30 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 1.4 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of reinforcing fiber, 0.2 wt% of colloidal silica, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 4.0: 1, adding copper acetylide, heating at 98 ℃, reacting for 2.5h under the pressure of 1.2MPa to obtain a product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 132 ℃, adding copper powder, continuously raising the temperature to 225 ℃, maintaining for 2.5 hours, introducing ammonia gas and inert gas, keeping the mass ratio of the introduced ammonia gas to acetylene at 0.80:1, reacting for 2.5 hours, adding potassium hydroxide, and beginning to cool to 135 ℃ to obtain a product B;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, stirring uniformly, heating at 55 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 73 ℃, adding sulfuric acid and sulfur trioxide at a mass ratio of the added methylnaphthalene to acetylene of 100:1, heating to 140 ℃, maintaining for 3.5h, cooling to 123 ℃, adding deionized water for hydrolysis, continuously cooling to 82 ℃, adding recovered formaldehyde, heating to 107 ℃, and maintaining for 4.5h to obtain a product C;
s3, preparation of a dispersing agent:
mixing the obtained product polyvinylpyrrolidone with the product C to obtain a dispersing agent;
s4, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fiber, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 20rpm, the extrusion temperature is 250 ℃, and the temperature of a casting roll is 10 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 90 ℃, and the stretching ratio of the longitudinal stretching is 5;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 100 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the secondary transverse stretching temperature is 120 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 90 ℃.
Example 5
A high-flexibility lithium ion battery film is prepared from 70 wt% of pore-foaming agent, 28 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 0.4 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of reinforcing fiber, 0.2 wt% of colloidal silica, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 4.7: 1, adding acetylene copper, heating at 100 ℃, reacting for 3 hours under the pressure of 1.5MPa to obtain a product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 135 ℃, adding copper powder, continuously raising the temperature to 230 ℃, maintaining for 3 hours, introducing ammonia gas and inert gas, keeping the mass ratio of the introduced ammonia gas to acetylene at 0.85:1, reacting for 3 hours, adding potassium hydroxide, and beginning to cool to 140 ℃ to obtain a product B;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at the temperature of 60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 75 ℃, adding sulfuric acid and sulfur trioxide at a mass ratio of the added methylnaphthalene to acetylene of 120:1, heating to 150 ℃, maintaining for 3-4h, cooling to 125 ℃, adding deionized water for hydrolysis, continuously cooling to 85 ℃, adding recovered formaldehyde, heating to 110 ℃, and maintaining for 5h to obtain a product C;
s3, preparation of a dispersing agent:
mixing the obtained product polyvinylpyrrolidone with the product C to obtain a dispersing agent;
s4, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 25rpm, the extrusion temperature is 240 ℃, and the temperature of a casting roll is 22 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 110 ℃, and the stretching ratio of the longitudinal stretching is 9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 110 ℃;
(4) and (3) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the temperature of the secondary transverse stretching is 125 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to secondary transverse stretching, wherein the heat setting temperature is 80 ℃.
Comparative example 1
A high-flexibility lithium ion battery film is prepared from 70 wt% of pore-foaming agent, 28 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 0.8 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following specific steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 4.7: 1, adding acetylene copper, heating at 100 ℃, reacting for 3 hours under the pressure of 1.5MPa to obtain a product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 135 ℃, adding copper powder, continuously raising the temperature to 230 ℃, maintaining for 3 hours, introducing ammonia gas and inert gas, keeping the mass ratio of the introduced ammonia gas to acetylene at 0.85:1, reacting for 3 hours, adding potassium hydroxide, and beginning to cool to 140 ℃ to obtain a product B;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at the temperature of 60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 75 ℃, adding sulfuric acid and sulfur trioxide at a mass ratio of the added methylnaphthalene to acetylene of 120:1, heating to 150 ℃, maintaining for 3-4h, cooling to 125 ℃, adding deionized water for hydrolysis, continuously cooling to 85 ℃, adding recovered formaldehyde, heating to 110 ℃, and maintaining for 5h to obtain a product C;
s3, preparation of a dispersing agent:
mixing the obtained product polyvinylpyrrolidone with the product C to obtain a dispersing agent;
s4, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 25rpm, the extrusion temperature is 240 ℃, and the temperature of a casting roll is 22 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 110 ℃, and the stretching ratio of the longitudinal stretching is 9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 110 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the temperature of the secondary transverse stretching is 125 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80 ℃.
Comparative example 2
A high-flexibility lithium ion battery film is prepared from 70 wt% of pore-foaming agent, 28 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 0.4 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of reinforcing fiber, 0.2 wt% of colloidal silica, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is fatty acid polyglycol ester, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 25rpm, the extrusion temperature is 240 ℃, and the temperature of a casting roll is 22 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 110 ℃, and the stretching ratio of the longitudinal stretching is 9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 110 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the temperature of the secondary transverse stretching is 125 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80 ℃.
Comparative example 3
A high-flexibility lithium ion battery film is prepared from 70 wt% of pore-foaming agent, 28 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 0.4 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of reinforcing fiber, 0.2 wt% of colloidal silica, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is polyvinylpyrrolidone.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
The pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the crosslinking agent is vinyl silane crosslinking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 4.7: 1, adding acetylene copper, heating at 100 ℃, reacting for 3 hours under the pressure of 1.5MPa to obtain a product A;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 135 ℃, adding copper powder, continuously raising the temperature to 230 ℃, maintaining for 3 hours, introducing ammonia gas and inert gas, keeping the mass ratio of the introduced ammonia gas to acetylene at 0.85:1, reacting for 3 hours, adding potassium hydroxide, and beginning to cool to 140 ℃ to obtain a product B;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at the temperature of 60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymer polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 25rpm, the extrusion temperature is 240 ℃, and the temperature of a casting roll is 22 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 110 ℃, and the stretching ratio of the longitudinal stretching is 9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 110 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the temperature of the secondary transverse stretching is 125 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80 ℃.
Comparative example 4
A high-flexibility lithium ion battery film is prepared from 70 wt% of pore-foaming agent, 28 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 0.4 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of reinforcing fiber, 0.2 wt% of colloidal silica, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 2.5: 1, adding copper acetylide, and heating at 100 ℃, wherein the reaction time is 3 hours, and the pressure is 1.5MPa to obtain a product A;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 135 ℃, adding copper powder, continuously raising the temperature to 230 ℃, maintaining for 3 hours, introducing ammonia gas and inert gas, keeping the mass ratio of the introduced ammonia gas to acetylene at 0.85:1, reacting for 3 hours, adding potassium hydroxide, and beginning to cool to 140 ℃ to obtain a product B;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at the temperature of 60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 25rpm, the extrusion temperature is 240 ℃, and the temperature of a casting roll is 22 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 110 ℃, and the stretching ratio of the longitudinal stretching is 9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 110 ℃;
(4) and (3) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the temperature of the secondary transverse stretching is 125 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80 ℃.
Comparative example 5
The high-flexibility lithium ion battery film is prepared from the following raw materials, by weight, 70% of pore-foaming agent, 28% of ultra-high molecular weight polyethylene, 0.2% of polycarbonate, 0.4% of random copolymer polypropylene, 0.2% of chlorinated polyethylene, 0.2% of polymethyl methacrylate, 0.2% of dispersing agent, 0.2% of reinforcing fiber, 0.2% of colloidal silica, 0.2% of compatilizer and 0.2% of crosslinking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 2.5: 1, adding acetylene copper, heating at 100 ℃, reacting for 3 hours under the pressure of 1.5MPa to obtain a product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 135 ℃, adding copper powder, continuously raising the temperature to 230 ℃, maintaining for 3 hours, introducing ammonia gas and inert gas, keeping the mass ratio of the introduced ammonia gas to acetylene at 0.85:1, reacting for 3 hours, adding potassium hydroxide, and beginning to cool to 140 ℃ to obtain a product B;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at the temperature of 60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 75 ℃, adding sulfuric acid and sulfur trioxide at a mass ratio of the added methylnaphthalene to acetylene of 120:1, heating to 150 ℃, maintaining for 3-4h, cooling to 125 ℃, adding deionized water for hydrolysis, continuously cooling to 85 ℃, adding recovered formaldehyde, heating to 110 ℃, and maintaining for 5h to obtain a product C;
s3, preparation of a dispersing agent:
mixing the obtained product polyvinylpyrrolidone with the product C to obtain a dispersing agent;
s4, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 25rpm, the extrusion temperature is 240 ℃, and the temperature of a casting roll is 22 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 110 ℃, and the stretching ratio of the longitudinal stretching is 9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 110 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the temperature of the secondary transverse stretching is 125 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80 ℃.
Comparative example 6
A high-flexibility lithium ion battery film is prepared from 70 wt% of pore-foaming agent, 28 wt% of ultrahigh molecular weight polyethylene, 0.2 wt% of polycarbonate, 0.4 wt% of random copolymerization polypropylene, 0.2 wt% of chlorinated polyethylene, 0.2 wt% of polymethyl methacrylate, 0.2 wt% of dispersing agent, 0.2 wt% of reinforcing fiber, 0.2 wt% of colloidal silica, 0.2 wt% of compatilizer and 0.2 wt% of cross-linking agent.
The dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
The dispersant also includes methylnaphthalene.
The polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
The catalyst is copper acetylide, nickel, copper and potassium hydroxide.
A preparation method of a high-flexibility lithium ion battery film comprises the following steps,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, and adding the formaldehyde and the acetylene in a mass ratio of 4.7: 1, adding acetylene copper, heating at 100 ℃, reacting for 3 hours under the pressure of 1.5MPa to obtain a product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating to 135 ℃, adding copper powder, continuously raising the temperature to 230 ℃, maintaining for 3 hours, introducing ammonia gas and inert gas, keeping the mass ratio of the introduced ammonia gas to acetylene at 0.85:1, reacting for 3 hours, adding potassium hydroxide, and beginning to cool to 140 ℃ to obtain a product B;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at the temperature of 60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 75 ℃, adding sulfuric acid and sulfur trioxide at a mass ratio of the added methylnaphthalene to acetylene of 120:1, heating to 150 ℃, maintaining for 3-4h, cooling to 125 ℃, adding deionized water for hydrolysis, continuously cooling to 85 ℃, adding recovered formaldehyde, heating to 110 ℃, and maintaining for 5h to obtain a product C;
s3, preparation of a dispersing agent:
mixing the obtained product polyvinylpyrrolidone with the product C to obtain a dispersing agent;
s4, preparing a diaphragm:
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymerization polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fiber, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 25rpm, the extrusion temperature is 180 ℃, and the temperature of a casting roll is 40 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 110 ℃, and the stretching ratio of the longitudinal stretching is 9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 110 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through an extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the temperature of the secondary transverse stretching is 125 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80 ℃.
Experiment of the invention
Taking example 5 as a control, setting comparative examples 1, 2, 3 and 4, wherein no reinforcing fiber and colloidal silica are added in comparative example 1, conventional dispersant fatty acid polyglycol ester is used for replacing in comparative example 2, formaldehyde is not recovered and treated in comparative example 3, and no methylnaphthalene is added, and the mass ratio of formaldehyde to acetylene added in comparative example 4 is 2.5: 1, in comparative example 5, without adding methylnaphthalene, the mass ratio of formaldehyde to acetylene added was 2.5: 1, methylnaphthalene was added, and in comparative example 6, the control experiment was performed with the extrusion temperature defined as 180 ℃ and the casting roll temperature defined as 40 ℃.
The polyvinylpyrrolidones obtained in example 1, example 2, example 3, comparative example 1, comparative example 2, comparative example 3, comparative example 4 and comparative example 5 were analyzed, and as a result,
Figure BDA0003138555070000181
Figure BDA0003138555070000191
watch 1
The dispersants obtained in example 1, example 2, example 3, comparative example 1, comparative example 2, comparative example 3, comparative example 4, and comparative example 5 were analyzed, and as a result,
experimental group Formic acid Polyvinylpyrrolidone Methylnaphthalene Acetylene
Example 1 ---- ---- ---- ----
Example 2 ---- ---- ---- ----
Example 3 Not detected out Not detected out Not detected out Undetected
Example 4 Not detected out Not detected out Not detected out Not detected out
Example 5 Not detected out Not detected out Not detected out Not detected out
Comparative example 1 Not detected out Detect out Not detected out Not detected out
Comparative example 2 ---- ---- ---- ----
Comparative example 3 Detect out Detect out ---- Undetected
Comparative example 4 Detect out Detect out ---- Detect out
Comparative example 5 Detect out Detect out Detect out Detect out
Watch 2
The product films obtained in example 1, example 2, example 3, comparative example 1, comparative example 2 and comparative example 3 were subjected to a test, and the results were as follows,
experimental group Tortuosity of
Example 1 6
Example 2 7
Example 3 8
Example 4 9
Example 5 8
Comparative example 1 4
Comparative example 2 5
Comparative example 3 5
Table three the product films obtained in example 1, example 2, example 3 and comparative example 6 were tested, and the results were as follows,
Figure BDA0003138555070000192
Figure BDA0003138555070000201
watch four
As can be seen from the table, in comparative example 3, formic acid and acetylene can be detected, which shows that formaldehyde remains and is oxidized into formic acid during the reaction process, and that formaldehyde is excessively added in order to ensure that acetylene is completely converted during the preparation process, so that a large amount of formaldehyde remains and is oxidized in the air to form formic acid, thereby showing the importance of examples 1, 2 and 3 on formaldehyde treatment. In comparative example 4 and comparative example 5, it can be seen that the reduction of the added amount of formaldehyde leads to the detection of formic acid and acetylene, which indicates that the subsequent reaction of formaldehyde and acetylene is slow and formaldehyde and acetylene are remained, which indicates that the quality limitation of the added formaldehyde and acetylene in examples 1, 2 and 3 can not only ensure the complete reaction of acetylene but also ensure the minimum residual amount of methylnaphthalene, and the importance of controlling the added amount can be seen from table two.
According to the table three, the tortuosity of the embodiment 1 and the embodiment 2 is 6-7, the tortuosity of the embodiment 3, the embodiment 4 and the embodiment 5 is 8-9, which shows that the dispersant MF added in the application has certain effect and can increase the tortuosity, the tortuosity of the comparative example 1 is 4, which shows that the added reinforcing fiber and the colloidal silica are more helpful to form an irregular three-dimensional net space structure, so as to improve the tortuosity of a microporous structure, the tortuosity of the comparative example 2 is 5, which shows that the polyvinylpyrrolidone is used, which can promote the polymer polyethylene and the crystalline auxiliary materials and non-crystalline auxiliary materials with complex molecular chains to be more finely mixed and melted, so as to further obtain a molecular chain structure with fine and complex entanglement, the tortuosity of the comparative example 3 is 5, which shows that the added methylnaphthalene can react with formaldehyde, and the obtained product can be matched with the polyvinylpyrrolidone, thereby improving the tortuosity.
According to the fourth table, the pore diameter of the membrane can be influenced by limiting the extrusion temperature and the casting sheet roller temperature, the extrusion temperature is controlled to be 200-250 ℃, the casting sheet roller temperature is controlled to be 10-22 ℃, and the pore diameter of the product membrane can be ensured to be small.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A high-tortuosity lithium ion battery film is characterized in that: the battery film is prepared from 67-74 wt% of pore-foaming agent, 25-30 wt% of ultra-high molecular weight polyethylene, 0.1-0.2 wt% of polycarbonate, 0.1-2 wt% of random copolymerization polypropylene, 0.1-0.2 wt% of chlorinated polyethylene, 0.1-0.2 wt% of polymethyl methacrylate, 0.1-0.2 wt% of dispersing agent, 0.1-0.2 wt% of reinforcing fiber, 0.1-0.2 wt% of colloidal silicon dioxide, 0.1-0.2 wt% of compatilizer and 0.1-0.2 wt% of cross-linking agent.
2. The highly tortuous lithium ion battery film of claim 1, wherein: the dispersing agent is polyvinylpyrrolidone, the pore-forming agent is white oil, the compatilizer is maleic anhydride grafted compatilizer, the cross-linking agent is vinyl silane cross-linking agent, and the molecular weight of the ultra-high molecular weight polyethylene is 2000000.
3. The highly tortuous lithium ion battery film of claim 1, wherein: the dispersant also includes methylnaphthalene.
4. The highly tortuous lithium ion battery film of claim 2, wherein: the polyvinylpyrrolidone is prepared from formaldehyde, acetylene, a catalyst and hydrogen.
5. The highly tortuous lithium ion battery film of claim 4 wherein: the catalyst is copper acetylide, nickel, copper and potassium hydroxide.
6. A preparation method of a high-flexibility lithium ion battery film is characterized by comprising the following steps: the steps are as follows,
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymer polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, stirring uniformly, adding a pore-foaming agent, stirring uniformly, and extruding the pore-foaming agent;
(2) longitudinal stretching: longitudinally stretching the extruded sheet;
(3) primary transverse stretching: transversely stretching the film after longitudinal stretching;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through the extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out;
(5) heat setting: and (4) performing heat setting treatment on the film subjected to the secondary transverse stretching.
7. The method for preparing the high-tortuosity lithium ion battery film according to claim 6, characterized in that: the method comprises the following specific steps of,
(1) mixing materials: mixing ultra-high molecular weight polyethylene with polycarbonate, random copolymer polypropylene, chlorinated polyethylene, polymethyl methacrylate, a dispersing agent, reinforcing fibers, colloidal silica, a compatilizer and a crosslinking agent, uniformly stirring, adding a pore-foaming agent, uniformly stirring, extruding the pore-foaming agent, wherein the rotating speed of an extrusion screw is 20-30rpm, the extrusion temperature is 200-250 ℃, and the temperature of a casting roller is 10-22 ℃;
(2) longitudinal stretching: longitudinally stretching the extruded sheet, wherein the stretching temperature of the longitudinal stretching is 90-110 ℃, and the stretching ratio of the longitudinal stretching is 5-9;
(3) primary transverse stretching: carrying out primary transverse stretching on the longitudinally stretched film, wherein the primary transverse stretching temperature is 100-110 ℃;
(4) secondary transverse stretching: the film after the primary transverse stretching passes through the extraction solvent, white oil in the film is removed, and secondary transverse stretching is carried out, wherein the secondary transverse stretching temperature is 120-130 ℃;
(5) heat setting: and (3) performing heat setting treatment on the film subjected to the secondary transverse stretching, wherein the heat setting temperature is 80-100 ℃.
8. The method for preparing a high-tortuosity lithium ion battery film according to claim 7, characterized in that: the preparation steps of the dispersing agent are as follows,
s1, preparation of polyvinylpyrrolidone:
(1) mixing formaldehyde and acetylene, adding copper acetylide, heating at 95-100 deg.C for 2-3h under 1-1.5MPa to obtain product A, and recovering formaldehyde;
(2) dissolving the product A, adding nickel, uniformly stirring, introducing hydrogen and inert gas, heating at the temperature of 130-;
(3) treating the obtained product B, recovering the catalyst, adding hydrogen peroxide and azodiisobutyronitrile, uniformly stirring, heating at 50-60 ℃, and adding ammonia water to obtain a product polyvinylpyrrolidone;
s2, treatment of formaldehyde:
heating methylnaphthalene at 70-75 ℃, adding sulfuric acid and sulfur trioxide, raising the temperature, keeping the temperature at 135-150 ℃, maintaining the temperature for 3-4h, lowering the temperature at 120-125 ℃, adding deionized water for hydrolysis, continuing to lower the temperature at 75-85 ℃, adding recovered formaldehyde, raising the temperature at 105-110 ℃, and maintaining the temperature for 4-5h to obtain a product C;
s3, preparation of a dispersing agent:
and mixing the obtained product polyvinylpyrrolidone with the product C to obtain the dispersing agent.
9. The method for preparing a highly-tortuous lithium ion battery film according to claim 8, characterized by comprising the following steps: in the step (1) of the step S1, adding formaldehyde and acetylene in a mass ratio of 3.5-4.7: 1; in the step (2) of the step S1, the mass ratio of the introduced ammonia gas to the acetylene is 0.78-0.85: 1.
10. The method for preparing a highly-tortuous lithium ion battery film according to claim 8, characterized by comprising the following steps: in step S2, the mass ratio of the methylnaphthalene to the acetylene is 90-120: 1.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102064300A (en) * 2010-12-25 2011-05-18 佛山塑料集团股份有限公司 Porous composite diaphragm for lithium ion secondary battery and preparation method thereof
CN104022250A (en) * 2014-06-26 2014-09-03 佛山市盈博莱科技有限公司 Lithium ion battery diaphragm and preparation method
CN110828751A (en) * 2019-11-06 2020-02-21 江苏厚生新能源科技有限公司 Preparation method of polyethylene diaphragm with multilayer microporous structure

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102064300A (en) * 2010-12-25 2011-05-18 佛山塑料集团股份有限公司 Porous composite diaphragm for lithium ion secondary battery and preparation method thereof
CN104022250A (en) * 2014-06-26 2014-09-03 佛山市盈博莱科技有限公司 Lithium ion battery diaphragm and preparation method
CN110828751A (en) * 2019-11-06 2020-02-21 江苏厚生新能源科技有限公司 Preparation method of polyethylene diaphragm with multilayer microporous structure

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