Composite polymer film, method for manufacturing the same, metallized composite polymer film and use

Abstract

The present application relates to a composite polymer film, its manufacturing method, metallized composite polymer film, and use. The composite polymer film of the present application includes a surface layer 1, a surface layer 2, and a core layer located between the surface layers 1 and 2. In mass %, the raw materials for the core layer include 98% to 99.8% polyester material, 0.1% to 1% inorganic nanomaterial, and 0.1% to 1% antioxidant, and the raw materials for the surface layers 1 and 2 each independently include 88% to 98.8% polyester material, 1% to 10% nanooxide, and 0.2% to 2% additive.

Description

【Technical Field】 【0001】 This application relates to the technical field of batteries, and particularly to composite polymer films, methods for manufacturing the same, metallized composite polymer films, and their uses. 【Background Art】 【0002】 Metallized polymer films are widely used in fields such as electronics, packaging, and printing due to their excellent performance such as conductivity, barrier properties, flexibility, and light weight. Metallized polymer film products include composite current collectors, thin film electrodes, packaging aluminum-plated films, printing thin films, etc. The manufacturing process of composite current collectors usually involves depositing a layer of metal material on a polymer thin film using a physical vapor deposition method to produce a thin film with a metallized surface having a certain conductivity, which is the composite current collector. Compared with conventional current collectors, composite current collectors made of polymer polymers have lower costs, lighter weights, and better internal insulation properties. Therefore, when such composite current collectors are applied to batteries, they can reduce the cost of the batteries and improve the energy density and safety of the batteries. However, the polyester films in the prior art have problems such as weak surface adhesiveness, low mechanical strength, and poor heat resistance. When the polyester film and the metal material are combined, the adhesion is poor, resulting in a low adhesion strength between the two. 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0003】 According to various embodiments of the present application, composite polymer films, methods for manufacturing the same, metallized composite polymer films, and their uses are provided. 【Means for Solving the Problems】 【0004】 This application has taken the following technical solutions. 【0005】 This application is a composite polymer film including a surface layer 1, a surface layer 2, and a core layer located between the surface layer 1 and the surface layer 2. The present invention provides a composite polymer film in which, by mass%, the raw materials for the core layer comprise 98% to 99.8% polyester material, 0.1% to 1% inorganic nanomaterial, and 0.1% to 1% antioxidant, and the raw materials for the surface layer 1 and the surface layer 2 each independently comprise 88% to 98.8% polyester material, 1% to 10% nanooxide, and 0.2% to 2% additive. 【0006】 In some embodiments, the nanooxide comprises one or more of aluminum oxide, silica, titanium dioxide, zinc oxide, copper oxide, magnesium oxide, ferric oxide, triiron tetroxide, zirconium dioxide, and tin dioxide. 【0007】 In some embodiments, the inorganic nanomaterial includes one or more of the following: nanooxides, graphene, graphene oxide, carbon nanotubes, and carbon nanofibers. 【0008】 In some embodiments, the polyester material includes one or more of the following: polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), polybutylene terephthalate (PBT), polycyclohexane-1,4-dimethylene terephthalate (PCT), polyethylene terephthalate-1,4-cyclohexanedimethylene terephthalate (PETG), polypropylene-2,6-naphthalenedicarboxylate (PTN), polytrimethylene terephthalate (PTT), polybutylene-2,6-naphthalenedicarboxylate (PBN), polybutylene-2,5-furanoleate, polybutylene adipate terephthalate (PBAT), polyarylate (PAR), and derivatives thereof. 【0009】 In some embodiments, the additive includes an antioxidant and a lubricant. Preferably, the antioxidant comprises one or more of phosphonic acid esters and bisphenol A phosphite. Preferably, the lubricant comprises one or more of the following: calcium carbonate, talc powder, kaolin, diatomaceous earth, siloxane, clay, mica, aluminum silicate, potassium phosphate, barium sulfate, and acrylic acid ester. 【0010】 In some embodiments, the thickness of the composite polymer film is 1 to 50 μm. Preferably, the percentages of the thickness of the core layer, surface layer 1, and surface layer 2 relative to the thickness of the composite polymer film are 70% to 90%, 5% to 15%, and 5% to 15%, respectively, and the thicknesses of surface layer 1 and surface layer 2 are equal. 【0011】 The present application relates to a method for manufacturing the composite polymer film described above, Step S1 is a step for producing polyester chips A, B, and C, respectively, wherein, by mass%, polyester chips A and C are each independently produced from 88% to 98.8% polyester material, 1% to 10% nanooxide and 0.2% to 2% additive, and polyester chip B is produced from 98% to 99.8% polyester material, 0.1% to 1% inorganic nanomaterial and 0.1% to 1% antioxidant. The step of melt-extruding the polyester chips A, B and C to obtain a molten polyester material having a core layer, a surface layer 1 and a surface layer 2, wherein the core layer is located between the surface layer 1 and the surface layer 2, Step S3 involves sequentially performing a molding process and a heat treatment on the molten polyester material, The present invention further provides a method for manufacturing a composite polymer film containing the above. 【0012】 In some embodiments, the heat treatment process in step S3 is The first stage involves a heat treatment temperature of 130-160°C and a heat treatment time of 0.5-2 min, The second stage involves a heat treatment temperature of 160-220°C and a heat treatment time of 0.5-5 min. This includes a third stage in which the heat treatment temperature is 130-160°C and the heat treatment time is 0.5-2 min. 【0013】 The present invention relates to a metallized composite polymer film comprising a composite polymer film which is the composite polymer film described above or a composite polymer film manufactured by the manufacturing method described above, and a metal conductive layer provided on at least one surface of the composite polymer film, Preferably, the material of the metallic conductive layer comprises one or more of the following: copper, copper alloys, aluminum, aluminum alloys, nickel, nickel alloys, titanium, and silver, further providing a metallized composite polymer film. 【0014】 In some embodiments, the thickness of the metal conductive layer is 20 to 2000 nm. 【0015】 The present invention further includes a composite current collector comprising the above-mentioned metallized composite polymer film. 【0016】 In some embodiments, the composite current collector further includes a protective layer located in the metallic conductive layer of the metallized composite polymer film. 【0017】 In some embodiments, the protective layer comprises one or more of the following: nickel, chromium, nickel-based alloys, copper-based alloys, copper oxide, aluminum oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, acetylene black, Ketjenblack, carbon nanoquantum dots, carbon nanotubes, carbon nanofibers, and graphene. 【0018】 In some embodiments, the thickness of the protective layer is 100 to 150 nm. 【0019】 Furthermore, the present application further provides an electrode piece including the composite current collector described above. 【0020】 Furthermore, the present application further provides a battery including the above electrode sheet. 【0021】 Even further, the present application further provides an electronic device including the above battery. 【0022】 Details of one or more embodiments of the present application are presented in the following description. Other features, objects, and advantages of the present application will become apparent from the specification and the claims. 【Embodiments for Carrying Out the Invention】 【0023】 Hereinafter, with reference to specific embodiments, the technical solution of the present application will be clearly and completely described. It is clear that the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application. 【0024】 Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "one or more" used herein includes any combination and all combinations of one or more related items. 【0025】 In the present application, regarding numerical intervals, unless otherwise specified, within the above numerical intervals, it is considered to include the continuous minimum and maximum values within the range, as well as each value between such minimum and maximum values. Further, when the range refers to an integer, each integer between the minimum and maximum values within the range is included. Also, when multiple ranges are provided to describe features or characteristics, those ranges can be combined. In other words, unless specifically stated, all ranges disclosed herein should be understood to include any and all sub-ranges included therein. 【0026】 According to one embodiment of the present invention, a composite polymer film comprising a surface layer 1, a surface layer 2, and a core layer located between the surface layer 1 and the surface layer 2, In mass%, the raw materials for the core layer consist of 98% to 99.8% polyester material, 0.1% to 1% inorganic nanomaterial, and 0.1% to 1% antioxidant, while the raw materials for the surface layer 1 and surface layer 2 independently consist of 88% to 98.8% polyester material, 1% to 10% nanooxide, and 0.2% to 2% additive, respectively, to provide a composite polymer film. 【0027】 Due to the weak surface polarity of polyester film (35 mN / m), the bonding strength with metal materials is poor. Furthermore, because the tensile strength of polyester film is generally less than 250 MPa, in the environment of a PVD (Physical Vapor Deposition) system, the polyester film is prone to breakage due to the pressure of the winding system, the impact of metal atoms, and the rise in the surface temperature of the polyester film. In addition, the poor heat resistance of polyester film makes it susceptible to shrinkage due to heat, and the impact and deposition of high-temperature metal atoms can cause shrinkage, leading to product defects and poor heat resistance of composite current collectors. Moreover, when composite current collectors are applied to batteries, high requirements are placed on the tensile strength of the polyester film due to the associated coating and composite molding processes. 【0028】 In view of this, the present invention provides a composite polymer film that improves the mechanical performance and heat resistance of the core layer through intermolecular forces between inorganic nanomaterials and polyester materials, and improves the surface polarity and heat resistance of both by the segregation of nanooxides on the surfaces of surface layers 1 and 2 during the film formation and cooling process. Therefore, the composite polymer film according to the present invention has the advantages of good surface adhesion, high mechanical strength, good processability, and good heat resistance. When a metallized composite polymer film is manufactured using this composite polymer film as a base film, the bonding strength between the composite polymer film and the surface metal conductive layer is also greatly improved. The content of inorganic nanomaterials in the core layer and nanooxides in surface layers 1 and 2 of the composite polymer film according to the present invention should not be too low or too high. If the content of inorganic nanomaterials and nanooxides is too low, the improvement in performance of the composite polymer film will not be significant, and if the content is too high, it will easily cause film formation defects. 【0029】 In some embodiments, the nanooxides include one or more of the following: aluminum oxide, silica, titanium dioxide, zinc oxide, copper oxide, magnesium oxide, ferric oxide, triiron tetroxide, zirconium dioxide, and tin dioxide. 【0030】 In some embodiments, the shape of the nanooxide includes one or more of spherical, linear, and tubular shapes. 【0031】 In some embodiments, the spherical nanooxides have a diameter of 5 to 80 nm, the linear nanooxides have a diameter of 3 to 30 nm and a length of 0.1 to 1 μm, and the tubular nanooxides have a diameter of 5 to 50 nm and a length of 0.1 to 1 μm. 【0032】 In some embodiments, the graphene flakes have a diameter of 0.2–2 μm, a thickness of 0.8–0.9 nm, and a single-walled proportion of 60–80%. The graphene oxide flakes have a diameter of 0.2–2 μm and a thickness of 0.8–1.2 nm. The carbon nanotubes are single-walled carbon nanotubes with a diameter of 4–5 nm and a length of 0.2–2 μm. The carbon nanofibers have a diameter of 20–80 nm and a length of 0.2–2 μm. 【0033】 Furthermore, this invention requires limiting the size of the nanooxides in surface layer 1 and surface layer 2. If the size of the nanooxides in surface layer 1 and surface layer 2 is too small, it is detrimental to improving the performance of the composite polymer film. If the size is too large, segregation on the surface of surface layer 1 and surface layer 2 is difficult, limiting the improvement of the bonding strength between the composite polymer film and the metal conductive layer, while also making it easier to cause film formation defects. 【0034】 It should be understood that nanooxides include one of the following: aluminum oxide, silica, titanium dioxide, zinc oxide, copper oxide, magnesium oxide, diiron trioxide, triiron tetroxide, zirconium dioxide, and tin dioxide, or a mixture of several of the following in any proportion. 【0035】 In some embodiments, the inorganic nanomaterial includes one or more of the following: nanooxides, graphene, graphene oxide, carbon nanotubes, and carbon nanofibers. 【0036】 It should be understood that inorganic nanomaterials include one of the following: nanooxides, graphene, graphene oxide, carbon nanotubes, and carbon nanofibers, or mixtures of multiple of these in any proportion. 【0037】 In some embodiments, the polyester material includes one or more of the following: polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), polybutylene terephthalate (PBT), polycyclohexane-1,4-dimethylene terephthalate (PCT), polyethylene terephthalate-1,4-cyclohexane-dimethylene terephthalate-dimethylene terephthalate (PETG), polypropylene-2,6-naphthalenedicarboxylate (PTN), polytrimethylene terephthalate (PTT), polybutylene-2,6-naphthalenedicarboxylate (PBN), polybutylene-2,5-furanoleate, polybutylene adipate terephthalate (PBAT), polyarylate (PAR), and derivatives thereof. 【0038】 It should be understood that polyester materials include any one of the following: polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), polybutylene terephthalate (PBT), polycyclohexane-1,4-dimethylene terephthalate (PCT), polyethylene terephthalate-1,4-cyclohexane-dimethylene terephthalate-dimethylene terephthalate (PETG), polypropylene-2,6-naphthalenedicarboxylate (PTN), polytrimethylene terephthalate (PTT), polybutylene-2,6-naphthalenedicarboxylate (PBN), polybutylene-2,5-furanoleate, polybutylene adipate terephthalate (PBAT), polyarylate (PAR), and their derivatives, or The polyester material includes a mixture formed in any proportion of several types of polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), polybutylene terephthalate (PBT), polycyclohexane-1,4-dimethylene terephthalate (PCT), polyethylene terephthalate-1,4-cyclohexane-dimethylene terephthalate-dimethylene terephthalate (PETG), polypropylene-2,6-naphthalenedicarboxylate (PTN), polytrimethylene terephthalate (PTT), polybutylene-2,6-naphthalenedicarboxylate (PBN), polybutylene-2,5-furanoleate, polybutylene adipate terephthalate (PBAT), polyarylate (PAR), and their derivatives. 【0039】 In some embodiments, the additives include antioxidants and lubricants. Preferably, the antioxidant comprises one or more of phosphonic acid esters and bisphenol A phosphite. Preferably, the lubricant includes one or more of the following: calcium carbonate, talc powder, kaolin, diatomaceous earth, siloxane, clay, mica, aluminum silicate, potassium phosphate, barium sulfate, and acrylic acid ester. 【0040】 It should be understood that antioxidants include phosphonic acid esters or bisphenol A phosphite, or antioxidants include mixtures formed by phosphonic acid esters and bisphenol A phosphite in any ratio. 【0041】 It should be understood that the lubricant contains one of the following: calcium carbonate, talc powder, kaolin, diatomaceous earth, siloxane, clay, mica, aluminum silicate, potassium phosphate, barium sulfate, or acrylic acid ester, or contains a mixture formed in any proportion of the following: calcium carbonate, talc powder, kaolin, diatomaceous earth, siloxane, clay, mica, aluminum silicate, potassium phosphate, barium sulfate, and acrylic acid ester. 【0042】 In some embodiments, the thickness of the composite polymer film is 1 to 50 μm. Preferably, the percentages of the core layer, surface layer 1, and surface layer 2 thicknesses relative to the composite polymer film thickness are 5% to 15%, 70% to 90%, and 70% to 90%, respectively, and the thicknesses of surface layer 1 and surface layer 2 are equal. 【0043】 In some embodiments, the thickness of the composite polymer film is 2 to 20 μm. 【0044】 It should be understood that the thickness of the composite polymer film may be any value between 1 and 50 μm or 2 and 20 μm, for example, 1 μm, 2 μm, 4 μm, 8 μm, 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 55 μm, etc. The percentages of the thickness of the core layer, surface layer 1, and surface layer 2 relative to the thickness of the composite polymer film may be any value between 70% and 90%, 5% and 15%, and 5% and 15%, respectively, and the ratio of the thicknesses of the core layer, surface layer 1, and surface layer 2 relative to the thickness of the composite polymer film may be, for example, 90%, 5%, and 5%, or 84%, 8%, and 8%, or 80%, 10%, and 10%, or 76%, 12%, and 12%, or 70%, 15%, and 15%. 【0045】 The present application relates to a method for manufacturing the composite polymer film described above, Step S1 is a step for producing polyester chips A, B, and C, respectively, wherein polyester chips A and C are each independently produced by mass%, consisting of 88% to 98.8% polyester material, 1% to 10% nanooxides, and 0.2% to 2% additives, and polyester chip B is produced by 98% to 99.8% polyester material, 0.1% to 1% inorganic nanomaterials, and 0.1% to 1% antioxidants. The process involves melt-extruding polyester chips A, B, and C to obtain a molten polyester material having a core layer, a surface layer 1, and a surface layer 2, wherein the core layer is located between surface layer 1 and surface layer 2, and the process is as follows: Step S3 involves sequentially molding and heat treatment of the molten polyester material, The present invention further provides a method for manufacturing a composite polymer film containing the above. 【0046】 Polyester chip A forms the surface layer 1, polyester chip B forms the core layer, and polyester chip C forms the surface layer 2. 【0047】 In the manufacturing process of the composite polymer film according to this invention, nanooxides segregate onto the surface of the composite polymer film, forming an organic-inorganic hybrid layer with a predominant nanooxide content. By utilizing the good bonding properties between nanooxides and metal materials, the bonding strength between the composite polymer film and the metal conductive layer is improved. 【0048】 In some embodiments, the molding process of step S3 includes the following steps: 【0049】 (1) Cast slab: The molten polyester material in step S2 is cast onto a cast slab roll, and a cast slab is obtained after water cooling treatment with the cast slab roll. 【0050】 (2) Longitudinal stretching: The above cast slab is preheated to 70-100°C and then subjected to longitudinal stretching to obtain a film piece. After that, it is heat-set at 165-180°C and cooled at 30-50°C. Here, the longitudinal stretching ratio is (3-5):1 and the longitudinal stretching temperature is 80-120°C. 【0051】 (3) Transverse stretching: The above film piece is preheated to 80-120°C, then subjected to transverse stretching, followed by heat setting at 150-250°C, and finally cooled at 80-150°C. Here, the transverse stretching ratio is (3-5):1, and the transverse stretching temperature is 90-140°C. 【0052】 In some embodiments, the heat treatment process in step S3 is The first stage involves a heat treatment temperature of 130-160°C and a heat treatment time of 0.5-2 min, The second stage involves a heat treatment temperature of 160-220°C and a heat treatment time of 0.5-5 min. The third stage involves a heat treatment temperature of 130-160°C and a heat treatment time of 0.5-2 min, Includes. 【0053】 The present invention relates to a metallized composite polymer film comprising a composite polymer film which is the composite polymer film described above or a composite polymer film manufactured by the manufacturing method described above, and a metal conductive layer provided on at least one surface of the composite polymer film, Preferably, the material of the metallic conductive layer comprises one or more of the following: copper, copper alloys, aluminum, aluminum alloys, nickel, nickel alloys, titanium, and silver, further providing a metallized composite polymer film. 【0054】 It should be understood that the metallic conductive layer may be made of one of the following: copper, copper alloys, aluminum, aluminum alloys, nickel, nickel alloys, titanium, and silver; or it may be made of multiple of the following: copper, copper alloys, aluminum, aluminum alloys, nickel, nickel alloys, titanium, and silver. 【0055】 In some embodiments, the thickness of the metal conductive layer is 20 to 2000 nm. 【0056】 In some embodiments, the thickness of the metallic conductive layer is 30 to 1000 nm. 【0057】 It should be understood that the thickness of the metallic conductive layer may be any value between 20 and 2000 nm or between 30 and 1000 nm. For example, the thickness of the metallic conductive layer may be 20 nm, 25 nm, 30 nm, 50 nm, 150 nm, 250 nm, 350 nm, 450 nm, 550 nm, 650 nm, 750 nm, 850 nm, 950 nm, 1000 nm, 1050 nm, 1150 nm, 1250 nm, 1350 nm, 1450 nm, 1550 nm, 1650 nm, 1750 nm, 1850 nm, 1950 nm, or 2000 nm. 【0058】 In some embodiments, the method for manufacturing the metal conductive layer includes one or more of the following: physical vapor deposition, plating, and electroless plating. Preferably, the physical vapor deposition method includes one or more of the following: resistance heating vacuum deposition, electron beam heating vacuum deposition, laser heating vacuum deposition, and magnetron sputtering. 【0059】 In some embodiments, the thickness of the composite polymer film among the metallized composite polymer films is 1 to 20 μm. 【0060】 It should be understood that the thickness of the composite polymer film in the metallized composite polymer film may be any value between 1 and 20 μm. For example, the thickness of the composite polymer film in the metallized composite polymer film may be 1 μm, 3 μm, 5 μm, 7 μm, 9 μm, 11 μm, 13 μm, 15 μm, 17 μm, 19 μm, or 20 μm. 【0061】 This application further provides a composite current collector including the above-mentioned metallized composite polymer film. 【0062】 In some embodiments, the composite current collector further includes a protective layer located on the metallic conductive layer of the metallized composite polymer film. 【0063】 In some embodiments, the protective layer comprises one or more of the following: nickel, chromium, nickel-based alloys, copper-based alloys, copper oxide, aluminum oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, acetylene black, Ketjen black, carbon nanoquantum dots, carbon nanotubes, carbon nanofibers, and graphene. 【0064】 In some embodiments, the thickness of the protective layer is 10 to 150 nm. 【0065】 In some embodiments, the thickness of the protective layer is 20 to 100 nm. 【0066】 It should be understood that the thickness of the protective layer may be any value between 10 and 150 nm or between 20 and 100 nm. For example, the thickness of the protective layer may be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 45 nm, 55 nm, 65 nm, 75 nm, 85 nm, 95 nm, 100 nm, 105 nm, 115 nm, 125 nm, 135 nm, 145 nm, or 150 nm. 【0067】 In some embodiments, the method for manufacturing the protective layer includes one or more of the following: physical vapor deposition, in-situ molding, and coating. 【0068】 In some embodiments, the physical vapor deposition method includes one or more of the vacuum deposition method and the magnetron sputtering method. 【0069】 In some embodiments, the in-situ forming method includes a method for in-situ forming a metal oxide blunting layer on the surface of a metal conductive layer. 【0070】 In some embodiments, the coating method includes one or more of the die coating method, knife coating method, and squeeze coating method. 【0071】 In some embodiments, the protective layer consists of two layers, the materials of the two protective layers may be the same or different, and the thicknesses of the two protective layers may be equal or unequal. 【0072】 Furthermore, the present application further provides an electrode piece including the composite current collector described above. 【0073】 It should be understood that the electrode pieces of this application can be obtained by mixing a positive electrode active material / negative electrode active material, a conductive agent, a binder, and a solvent to form a slurry, and then applying the slurry to the composite current collector according to this application using an electrode piece manufacturing method familiar to those skilled in the art. Depending on the active material, the electrode pieces can be divided into positive electrode pieces and negative electrode pieces. The manufacturing method of the electrode pieces is familiar to those skilled in the art and is not particularly limited in this application. 【0074】 Furthermore, the present invention further provides a battery including the above-mentioned electrode piece. 【0075】 It should be understood that the battery relating to this application may be a lithium-ion secondary battery, a lithium-ion polymer secondary battery, a lithium metal secondary battery, or a lithium polymer secondary battery, and the battery is not particularly limited in this application. 【0076】 Furthermore, the present invention further provides an electronic device including the above-mentioned battery. 【0077】 It should be understood that the electronic device relating to this application is not particularly limited and may include, for example, electric vehicles, smart home appliances, digital cameras, mobile phones, computers, etc., and the battery relating to this application is used in the electronic device as a power source or energy storage unit. 【0078】 The present application will be described in more detail below with reference to specific examples and comparative examples. 【0079】 Example 1 The polyester material for the core layer, surface layer 1, and surface layer 2 is polyethylene terephthalate (PET) resin with an intrinsic viscosity of 0.731 dL / g and a molecular weight distribution of 2.2. 【0080】 The inorganic nanomaterial for the core layer was spherical nanoaluminum oxide (average diameter 40 nm), and the additive for the core layer was antioxidant 1222. 【0081】 Both the surface layer 1 and surface layer 2 use spherical nanosilica (average diameter 30 nm) as nanooxides, with antioxidant 1222 as the antioxidant and calcium carbonate as the lubricant. 【0082】 The method for manufacturing a composite polymer film includes the following steps: 【0083】 S1: Manufacturing of polyester chips A, polyester chips B, and polyester chips C 【0084】 Polyester chips A and C were produced independently by sequentially heating, melting, mixing, extruding, and shaping 98% PET resin, 1% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate, respectively, while polyester chip B was produced by sequentially heating, melting, mixing, extruding, and shaping 99.4% PET resin, 0.1% nanoaluminum oxide, and 0.5% antioxidant 1222, respectively. The produced polyester chips A, B, and C were then sent into a crystallization apparatus and treated at 140°C for 40 minutes. After crystallization, the polyester chips A, B, and C were sent into a drying apparatus and dried at 150°C for 160 minutes. 【0085】 S2: Manufacturing of molten polyester material 【0086】 The polyester chips A, B, and C obtained in step S1 were fed into different twin-screw extruders and melted at 280°C. The molten material was then extruded through a die using a metering pump to obtain a molten polyester material having a core layer, surface layer 1, and surface layer 2. The core layer was located between surface layer 1 and surface layer 2, with the extrusion ratios of the core layer, surface layer 1, and surface layer 2 being 80%, 10%, and 10% respectively (by mass). Polyester chip A formed surface layer 1, polyester chip B formed the core layer, and polyester chip C formed surface layer 2. 【0087】 S3: Manufacturing of composite polymer films 【0088】 S3.1: Molding process 【0089】 (1) Cast slab: The molten polyester material in step S2 was cast onto a cast slab roll, and a cast slab was obtained after water cooling treatment with the cast slab roll. 【0090】 (2) Longitudinal stretching: The above cast slab was preheated to 90°C and then subjected to longitudinal stretching to obtain a film piece. After heat setting at 170°C, it was cooled at 40°C. Here, the longitudinal stretching ratio was 4:1 and the longitudinal stretching temperature was 110°C. 【0091】 (3) Transverse stretching: The above film piece was preheated to 90°C, then subjected to transverse stretching, heat-set at 170°C, and then cooled at 110°C. Here, the transverse stretching ratio was 4:1 and the transverse stretching temperature was 120°C. 【0092】 S3.2: Heat treatment 【0093】 A composite polymer film was produced by heat-treating the film pieces obtained in S3.1. The thickness of the composite polymer film was 6 μm, and the heat treatment process included the following steps. 【0094】 Stage 1: The heat treatment temperature is 140°C and the heat treatment time is 0.5 min. 【0095】 Stage 2: The heat treatment temperature is 160°C and the heat treatment time is 0.5 min. 【0096】 Stage 3: The heat treatment temperature is 140°C and the heat treatment time is 0.5 min. 【0097】 The composite current collector is manufactured according to the following method. 【0098】 (1) Manufacturing of a metal conductive layer 【0099】 The manufactured composite polymer film was placed in a vacuum deposition chamber, and high-purity aluminum wire (purity exceeding 99.99%) in the metal evaporation chamber was melted and evaporated under conditions of 1300-2000°C. The evaporated metal atoms passed through the cooling system in the vacuum deposition chamber and deposited on two surfaces of the composite polymer film, forming a 1 μm thick aluminum metal conductive layer. 【0100】 (2) Manufacturing of the protective layer 【0101】 1 g of carbon nanotubes was uniformly dispersed in 999 g of N-methylpyrrolidone (NMP) by ultrasonic dispersion to prepare a coating solution with a solid content of 0.1 wt%. This coating solution was then uniformly applied to the surface of a metal conductive layer using a die-coating process, with the coating amount limited to 90 μm. Finally, it was dried at 100°C. 【0102】 Example 2 Step S1 is essentially the same as in Example 1, except that the polyester chip A and polyester chip C layers were independently manufactured by mass%, consisting of 96% PET resin, 3% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate, respectively. 【0103】 Example 3 Step S1 is essentially the same as in Example 1, except that the polyester chip A and polyester chip C layers were independently manufactured by mass%, each consisting of 94% PET resin, 5% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate. 【0104】 Example 4 Step S1 is essentially the same as in Example 1, except that the polyester chip A and polyester chip C layers were independently manufactured by mass%, consisting of 92% PET resin, 7% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate, respectively. 【0105】 Example 5 Step S1 is essentially the same as in Example 1, except that the polyester chip A and polyester chip C layers were independently manufactured by mass%, consisting of 90% PET resin, 9% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate, respectively. 【0106】 Example 6 Step S1 is essentially the same as in Example 1, except that the polyester chip A and polyester chip C layers were independently manufactured by mass%, each consisting of 89% PET resin, 10% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate. 【0107】 Example 7 This example is basically the same as Example 4, except that both the nanooxides for surface layer 1 and surface layer 2 are tubular nanosilica (25 nm in diameter, 0.4 μm in length). 【0108】 Example 8 This example is basically the same as Example 4, except that both the nanooxides for surface layer 1 and surface layer 2 are linear nanosilica (diameter 10 nm, length 0.5 μm). 【0109】 Example 9 This example is basically the same as Example 8, except that both the nano-oxides for surface layer 1 and surface layer 2 are linear nano-aluminum oxides (diameter 10 nm, length 0.5 μm). 【0110】 Example 10 This example is basically the same as Example 8, except that both the nano-oxides for surface layer 1 and surface layer 2 are linear nano-titanium dioxide (diameter 10 nm, length 0.5 μm). 【0111】 Example 11 Step S1 is essentially the same as in Example 8, except that the polyester chip B layer was manufactured using 99.2% PET resin, 0.3% nanoaluminum oxide, and 0.5% antioxidant 1222 by mass. 【0112】 Example 12 Step S1 is essentially the same as in Example 8, except that the polyester chip B layer is manufactured from 99.0% PET resin, 0.5% nanoaluminum oxide, and 0.5% antioxidant 1222 by mass. 【0113】 Example 13 Step S1 is essentially the same as in Example 8, except that the polyester chip B layer was manufactured using 98.8% PET resin, 0.7% nanoaluminum oxide, and 0.5% antioxidant 1222 by mass. 【0114】 Example 14 Step S1 is essentially the same as in Example 8, except that the polyester chip B layer was manufactured using 98.6% PET resin, 0.9% nanoaluminum oxide, and 0.5% antioxidant 1222 by mass. 【0115】 Example 15 Step S1 is essentially the same as in Example 8, except that the polyester chip B layer was manufactured using 98.5% PET resin, 1.0% nanoaluminum oxide, and 0.5% antioxidant 1222 by mass. 【0116】 Example 16 This example is basically the same as Example 12, except that the inorganic nanomaterial of the core layer is tubular nanoaluminum oxide (25 nm in diameter, 0.4 μm in length). 【0117】 Example 17 This example is basically the same as Example 12, except that the inorganic nanomaterial of the core layer is linear nanoaluminum oxide (diameter 10 nm, length 0.5 μm). 【0118】 Example 18 This example is basically the same as Example 17, except that the inorganic nanomaterial of the core layer is a single-walled carbon nanotube (diameter 5 nm, length 0.2 μm). 【0119】 Example 19 This example is basically the same as Example 17, except that the inorganic nanomaterial of the core layer is graphene (flake diameter 0.2 μm, thickness 0.8 nm, monolayer ratio 80%). 【0120】 Example 20 Step S3.2 is basically the same as in Example 19, except that the second stage of the heat treatment process is 1 minute. 【0121】 Example 21 Step S3.2 is basically the same as in Example 19, except that the second stage of the heat treatment process is 2 minutes. 【0122】 Example 22 Step S3.2 is basically the same as in Example 19, except that the second stage of the heat treatment process is 3 minutes. 【0123】 Example 23 Step S3.2 is basically the same as in Example 19, except that the second stage of the heat treatment process is 5 minutes. 【0124】 Example 24 In the second stage of the heat treatment process in step S3.2, the procedure is basically the same as in Example 21, except that the heat treatment temperature is 180°C. 【0125】 Example 25 In the second stage of the heat treatment process in step S3.2, it is basically the same as in Example 21, except that the heat treatment temperature is 200°C. 【0126】 Example 26 In the second stage of the heat treatment process in step S3.2, the procedure is basically the same as in Example 21, except that the heat treatment temperature is 220°C. 【0127】 Example 27 Step S1 is essentially the same as in Example 1, except that polyester chip A and polyester chip C are independently produced by mass % from 98.8% PET resin, 1% nanosilica, 0.1% antioxidant 1222, and 0.1% calcium carbonate, respectively. 【0128】 Example 28 Step S1 is essentially the same as in Example 1, except that polyester chip A and polyester chip C are independently produced by mass% from 88% PET resin, 10% nanosilica, 1% antioxidant 1222, and 1% calcium carbonate, respectively. 【0129】 Example 29 Step S1 is essentially the same as in Example 8, except that the polyester chip B was manufactured from 99.8% PET resin, 0.1% nanoaluminum oxide, and 0.1% antioxidant 1222 by mass. 【0130】 Example 30 Step S1 is essentially the same as in Example 8, except that the polyester chip B is made of 98% PET resin, 1% nanoaluminum oxide, and 1% antioxidant 1222 by mass. 【0131】 Comparative Example 1 Step S1 is basically the same as in Example 1, except that polyester chip A and polyester chip C layers are each independently manufactured from 99% PET resin, 0.5% antioxidant 1222, and 0.5% calcium carbonate by mass, and polyester chip B is manufactured from 99.5% PET resin and 0.5% antioxidant 1222. 【0132】 Comparative Example 2 Step S1 is essentially the same as in Example 1, except that the polyester chip A and polyester chip C layers were independently manufactured by mass%, consisting of 98.5% PET resin, 0.5% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate, respectively. 【0133】 Comparative Example 3 Step S1 is essentially the same as in Example 1, except that the polyester chip A and polyester chip C layers were independently manufactured by mass%, each consisting of 87% PET resin, 12% nanosilica, 0.5% antioxidant 1222, and 0.5% calcium carbonate. 【0134】 Comparative Example 4 Step S1 is essentially the same as in Example 8, except that the polyester chip B was manufactured from 99.45% PET resin, 0.05% nanoaluminum oxide, and 0.5% antioxidant 1222 by mass. 【0135】 Comparative Example 5 Step S1 is essentially the same as in Example 8, except that the polyester chip B was manufactured from 98% PET resin, 1.5% nanoaluminum oxide, and 0.5% antioxidant 1222 by mass. 【0136】 Comparative Example 6 Step S3.2 is basically the same as in Example 19, except that the second stage of the heat treatment process is 0.1 min. 【0137】 Comparative Example 7 Step S3.2 is basically the same as in Example 19, except that the second stage of the heat treatment process is 6 minutes. 【0138】 Comparative Example 8 In the second stage of the heat treatment process in step S3.2, the procedure is basically the same as in Example 21, except that the heat treatment temperature is 155°C. 【0139】 Comparative Example 9 Step S3.2 is basically the same as Example 21, except that the second stage of the heat treatment process is 225°C. 【0140】 Test Example 1: Performance Measurement of Composite Polymer Film and Composite Current Collector In reference to Chinese national standards GB / T 1040.3-2006 and GB / T 10003-2008, tensile strength, elongation at break, and thermal shrinkage rate were measured for manufactured composite polymer films and composite current collectors. 【0141】 The bonding strength between the composite polymer film and the metal conductive layer was measured. One layer of Permacel P-94 double-sided tape was adhered to a 1 mm thick aluminum foil, a composite current collector was adhered to the double-sided tape, and one layer of ethylene-acrylic copolymer thin film (DuPont Nurcel 0903, 50 μm thick) was coated on top of the composite current collector. Then, it was hot-pressed at 1.3 × 10⁵ N / m² and 120°C for 10 seconds, cooled to room temperature, and cut into 150 mm × 15 mm pieces. Finally, the ethylene-acrylic copolymer thin film of the sample piece was fixed to the upper jig of a tensile machine, and the remaining part was fixed to the lower jig. After fixing, the two were peeled off at an angle of 180° and a speed of 100 mm / min, and the peeling force, i.e., the bonding strength between the composite polymer film and the metal conductive layer, was measured. The measurement results are shown in Tables 1 and 2. 【0142】 [Table 1] 【0143】 Note: MD represents the longitudinal direction of the composite polymer film, and TD represents the transverse direction of the composite polymer film. The direction in which the longer side of the composite polymer film is the longitudinal direction, and the direction in which the shorter side is the transverse direction. The two directions are perpendicular to each other, and the heat shrinkage rate is data measured after heating the composite polymer film at 150°C for 30 minutes. 【0144】 [Table 2] 【0145】 Note: MD represents the longitudinal direction of the composite current collector, and TD represents the transverse direction of the composite current collector. The direction in which the longer side of the composite current collector is the longitudinal direction, and the direction in which the shorter side is the transverse direction. The two directions are perpendicular to each other, and the thermal shrinkage rate is data measured after heating the current collector at 150°C for 30 minutes. 【0146】 As can be seen from Tables 1-2, Examples 1-6 investigate the effect of changes in the nanosilica content in surface layer 1 and surface layer 2 on the performance of the composite polymer film. Examples 4, 7, and 8 investigate the effect of the silica shape in surface layer 1 and surface layer 2 on the performance of the composite polymer film. Examples 8-10 investigate the effect of the type of nanooxide in surface layer 1 and surface layer 2 on the performance of the composite polymer film. Examples 8 and 11-15 investigate the effect of the nanoaluminum oxide content in the core layer on the performance of the composite polymer film. Examples 12 and 16-17 investigate the effect of the nanoaluminum oxide shape in the core layer on the performance of the composite polymer film. Examples 17-19 investigate the effect of the type of inorganic nanomaterial in the core layer on the performance of the composite polymer film. Examples 19-23 investigated the effect of the heat treatment time in the second stage of the heat treatment process on the performance of the composite polymer film. By improving the heat treatment time in the second stage, the crystallinity of the composite polymer film can be improved, resulting in improved tensile strength and reduced thermal shrinkage and elongation at break. 【0147】 Examples 21 and 24-25 investigated the effect of the second-stage heat treatment temperature on the performance of the composite polymer film. By increasing the second-stage heat treatment temperature, the crystallinity of the composite polymer film could be improved, resulting in improved tensile strength and reduced thermal shrinkage and elongation at break. 【0148】 Compared to Examples 1-6 and 27-28, the composite polymer films produced in Comparative Examples 1-2 had lower tensile strength in both MD and TD directions, higher elongation at break and thermal shrinkage in both MD and TD directions, and weaker bonding strength with the metal conductive layer. Therefore, it has been found that if the amount of PET resin added to surface layer 1 and surface layer 2 in Comparative Examples 1-2 is too low or too high, it is detrimental to improving the surface bonding properties, mechanical strength, and heat resistance of the composite polymer film. 【0149】 Compared to Examples 1-6 and 27-28, the composite polymer film and composite current collector produced in Comparative Example 3 were found to have good heat resistance due to their small thermal shrinkage rate in both the MD and TD directions. However, their mechanical strength was found to be poor due to their significantly lower tensile strength in both the MD and TD directions. 【0150】 The composite polymer films produced in Comparative Examples 4-5 and Examples 11-15 and 30 all had a bonding strength of 4.5 N / cm with the metal conductive layer. However, compared to Examples 11-15 and 30, the composite polymer films and composite current collectors produced in Comparative Examples 4-5 had significantly lower tensile strength in both the MD and TD directions. This indicates that the mechanical strength of the composite polymer films and composite current collectors produced in Comparative Examples 4-5 is poor. 【0151】 The composite polymer films produced in Comparative Example 6 and Examples 19-23 all exhibited a bonding strength of 4.5 N / cm with the metal conductive layer. However, compared to Examples 19-23, the composite polymer film and composite current collector produced in Comparative Example 6 had relatively lower tensile strength in both the MD and TD directions, and relatively higher elongation at break and thermal shrinkage. Therefore, it was found that the mechanical strength and heat resistance of the composite polymer film and composite current collector produced in Comparative Example 6 were inferior. 【0152】 The composite polymer films produced in Comparative Examples 8-9 exhibited bonding strength with the metal conductive layer equivalent to that of Examples 21 and 24-26. However, the composite polymer films and composite current collectors produced in Comparative Examples 8-9 showed relatively low tensile strength in both the MD and TD directions, and relatively high elongation at break and thermal shrinkage rates. Therefore, it was found that the composite polymer films and composite current collectors produced in Comparative Examples 8-9 had poor mechanical strength. 【0153】 As can be seen from this, the composite polymer film according to the present invention exhibits significantly improved surface tackiness, mechanical strength, and heat resistance. 【0154】 The technical features of the embodiments described above can be combined in any way, and for the sake of brevity, not all possible combinations of the technical features in the embodiments described above have been described. However, these combinations of technical features should be considered to fall within the scope described herein, provided they are consistent. 【0155】 The embodiments described above are merely illustrative of some embodiments of the present application, and while their descriptions are more specific and detailed, they should not be understood as limiting the scope of the claims. Furthermore, those skilled in the art can make some modifications and improvements without departing from the spirit of the present application, and all such modifications and improvements should fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent is as defined in the attached claims.

Claims

[Claim 1] A composite polymer film comprising a surface layer 1, a surface layer 2, and a core layer located between the surface layer 1 and the surface layer 2, In mass%, the raw materials for the core layer consist of 98% to 99.8% polyester material, 0.1% to 1% inorganic nanomaterial, and 0.1% to 1% antioxidant, and the raw materials for the surface layer 1 and the surface layer 2 each independently consist of 88% to 98.8% polyester material, 1% to 10% nanooxide, and 0.2% to 2% additive. A composite polymer film characterized by the following features. [Claim 2] The nanooxide includes one or more of the following: aluminum oxide, silica, titanium dioxide, zinc oxide, copper oxide, magnesium oxide, diiron trioxide, triiron tetroxide, zirconium dioxide, and tin dioxide. The composite polymer film according to feature 1. [Claim 3] The inorganic nanomaterial includes one or more of the following: nanooxides, graphene, graphene oxide, carbon nanotubes, and carbon nanofibers. The composite polymer film according to feature 1. [Claim 4] The polyester material includes one or more of the following: polyethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polybutylene terephthalate, polycyclohexane-1,4-dimethylene terephthalate, polyethylene terephthalate-1,4-cyclohexane-dimethylene terephthalate-dimethylene terephthalate, polypropylene-2,6-naphthalenedicarboxylate, polytrimethylene terephthalate, polybutylene-2,6-naphthalenedicarboxylate, polybutylene-2,5-furanoleate, polybutylene adipate terephthalate, polyarylate, and derivatives thereof. The thickness of the composite polymer film is 1 to 50 μm. The composite polymer film according to feature 1. [Claim 5] The aforementioned additive includes an antioxidant and a lubricant. Preferably, the antioxidant comprises one or more of phosphonic acid esters and bisphenol A phosphite. Preferably, the lubricant comprises one or more of the following: calcium carbonate, talc powder, kaolin, diatomaceous earth, siloxane, clay, mica, aluminum silicate, potassium phosphate, barium sulfate, and acrylic acid ester. The composite polymer film according to feature 1. [Claim 6] A method for producing a composite polymer film according to any one of claims 1 to 5, Step S1 is a step for producing polyester chips A, B, and C, respectively, wherein, by mass%, polyester chips A and C are each independently produced from 88% to 98.8% polyester material, 1% to 10% nanooxide and 0.2% to 2% additive, and polyester chip B is produced from 98% to 99.8% polyester material, 0.1% to 1% inorganic nanomaterial and 0.1% to 1% antioxidant. The step of melt-extruding the polyester chips A, B, and C to obtain a molten polyester material having a core layer, a surface layer 1, and a surface layer 2, wherein the core layer is located between the surface layer 1 and the surface layer 2, Step S3 includes sequentially molding and heat treatment of the molten polyester material, The surface layer 1 is formed from the polyester chips A, the core layer is formed from the polyester chips B, and the surface layer 2 is formed from the polyester chips C. A method for producing a composite polymer film, characterized by the above. [Claim 7] The heat treatment process in step S3 is as follows: The first stage involves a heat treatment temperature of 130-160°C and a heat treatment time of 0.5-2 mins. The second stage involves a heat treatment temperature of 160-220°C and a heat treatment time of 0.5-5 mins. A third stage is included in which the heat treatment temperature is 130 to 160°C and the heat treatment time is 0.5 to 2 min. A method for producing a composite polymer film according to feature 6. [Claim 8] A metallized composite polymer film comprising a composite polymer film according to any one of claims 1 to 5, and a metal conductive layer provided on at least one surface of the composite polymer film, The thickness of the aforementioned metal conductive layer is 20 to 2000 nm. Preferably, the material of the metal conductive layer includes one or more of copper, copper alloys, aluminum, aluminum alloys, nickel, nickel alloys, titanium, and silver. A metallized composite polymer film characterized by the following features. [Claim 9] A metallized composite polymer film according to claim 8, A composite current collector characterized by the following features. [Claim 10] The aforementioned metallized composite polymer film further includes a protective layer located in the metal conductive layer, The protective layer includes one or more of the following: nickel, chromium, nickel-based alloy, copper-based alloy, copper oxide, aluminum oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, acetylene black, Ketjen black, carbon nanoquantum dots, carbon nanotubes, carbon nanofibers, and graphene. The thickness of the protective layer is 10 to 150 nm. The composite current collector according to feature 9. [Claim 11] Includes electrode pieces, The electrode piece includes the composite current collector described in claim 9. A battery characterized by the following features.

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