WO2024050693A1

WO2024050693A1 - Preparation method for modified polymer film, and modified polymer film and use thereof

Info

Publication number: WO2024050693A1
Application number: PCT/CN2022/117297
Authority: WO
Inventors: 朱中亚; 王帅; 夏建中; 李学法; 张国平
Original assignee: 扬州纳力新材料科技有限公司
Priority date: 2022-09-06
Filing date: 2022-09-06
Publication date: 2024-03-14

Abstract

The present application relates to a modified polymer film. The modified polymer film comprises a high-molecular polymer base film and a surface modified layer, wherein the surface modified layer is formed on at least one surface of the high-molecular polymer base film by means of a plasma polymerization method. The reaction raw materials of the surface modified layer comprise one or more of acrylic acid, acrylonitrile, allylamine, ethylenediamine, n-propylamine, methacrylic acid, methyl methacrylate and derivatives and copolymers thereof.

Description

Preparation method of modified polymer membrane, modified polymer membrane and use thereof

Technical field

The present application relates to the field of battery technology, and in particular to a preparation method of a modified polymer film, a modified polymer film and its use.

Background technique

Metalized polymer films are widely used in electronics, packaging, printing and other fields due to their excellent conductivity, barrier, flexibility and light weight properties. The more common metallized polymer film products currently on the market include composite current collectors, thin film electrodes, packaging aluminized films, printed films, etc. In traditional technology, physical vapor deposition technology is usually used to directly deposit metal on the surface of polypropylene, polyethylene, polyester and other polymer films to prepare metallized polymer films. However, during the actual preparation process of metallized polymer films, there is a problem that the polymer film and the surface metal layer are not firmly bonded.

Contents of the invention

According to various embodiments of the present application, a method for preparing a modified polymer film, a modified polymer film and uses thereof are provided.

In one aspect of the present application, a modified polymer film is provided. The modified polymer film includes a polymer base film and a surface modification layer. The surface modification layer is formed on the surface by a plasma polymerization method. At least one surface of the polymer base film.

In some embodiments, the reaction raw materials of the surface modification layer include acrylic acid, acrylonitrile, allylamine, ethylenediamine, n-propylamine, methacrylic acid, methyl methacrylate, and their derivatives and copolymers. one or more.

In some embodiments, the material of the polymer-based film includes polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate ester (PBT), polyethylene naphthalate (PEN), polyimide (PI), polypropylene, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) , polyphenylene sulfide (PPS), polyphenylene ether (PPO), polystyrene (PS), polyamide, polyimide and one or more of their derivatives.

In some embodiments, the thickness of the polymer base film is 1 μm or more.

In some embodiments, the thickness of the polymer base film is 2-20 μm.

In some embodiments, the thickness of the surface modification layer ranges from 5 to 200 nm.

In some embodiments, the thickness of the surface modification layer is 10-100 nm.

Another aspect of the present application provides a method for preparing the above-mentioned modified polymer film. The preparation method includes the following steps: performing plasma polymerization modification on the surface of the polymer-based film to at least One surface forms the surface modification layer.

In some embodiments, when performing plasma polymerization modification on the surface of the polymer base film, a mixed gas consisting of oxygen and argon and reaction raw materials are introduced;

The mixed gas bombards the surface of the polymer base film to provide reactive sites, and the reaction raw materials are grafted to the surface of the polymer base film through the reactive sites, thereby forming the reaction active sites. The surface modification layer.

In some embodiments, a plasma polymerization device is used to perform plasma polymerization modification on the surface of the polymer base film;

The plasma polymerization device includes a radio frequency power supply, the frequency of the radio frequency power supply is 3 to 30 MHz; the power of the plasma polymerization device is 10 to 50 W.

In some embodiments, the frequency of the radio frequency power supply is 10-20 MHz.

In some embodiments, the power of the plasma polymerization device is 20-40W.

In some embodiments, the reaction time of the plasma polymerization modification is 1 to 60 minutes.

Another aspect of the present application provides a metallized polymer film. The metalized polymer film includes a metal layer and the above-mentioned modified polymer film or the modified polymer film produced by the above-mentioned preparation method. The metal layer is located on On at least one surface modification layer of the modified polymer film;

Optionally, the material of the metal layer includes one or more of copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, titanium and silver.

Yet another aspect of the present application provides a composite current collector including the metallized polymer film described above.

In some embodiments, the composite current collector further includes a protective layer, the protective layer is disposed on the surface of the metal layer;

Optionally, the material of the protective layer includes 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, One or more of carbon nanoquantum dots, carbon nanotubes, carbon nanofibers and graphene;

Optionally, the thickness of the protective layer is 10-200nm;

Optionally, the thickness of the metal layer is 300-2000 nm.

In some embodiments, the thickness of the protective layer is 50-100 nm.

In some embodiments, the thickness of the metal layer ranges from 500 to 1000 nm.

Further, the present application provides an electrode pole piece, which includes the above composite current collector.

Further, the present application provides a battery, which includes the above-mentioned electrode pole piece.

Furthermore, the present application provides an electronic device, which includes the above-mentioned battery.

The details of one or more embodiments of the application are set forth in the description below. Other features, objects and advantages of the application will become apparent from the description and claims.

Detailed ways

The technical solution of the present application will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing specific embodiments only and is not intended to limit the application. As used herein, the term "one or more" includes any and all combinations of one or more of the associated listed items.

In this application, when it comes to numerical intervals, unless otherwise specified, the above numerical interval is considered to be continuous and includes the minimum value and maximum value of the range, as well as every value between such minimum value and maximum value. Further, when a range refers to an integer, every integer between the minimum value and the maximum value of the range is included. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood to include any and all subranges subsumed therein.

One embodiment of the present application provides a modified polymer film. The modified polymer film includes a polymer base film and a surface modification layer. The surface modification layer is formed on the polymer base through a plasma polymerization method. at least one surface of the membrane.

Traditional metallized polymer films have the problem that the polymer film is not firmly bonded to the metal layer on the surface. This is due to the weak polarity of polymer films such as polypropylene, polyethylene, and polyester, resulting in low surface tension. The affinity between the polymer film with low surface tension and the metal layer with high surface tension is poor, which leads to low adhesion between the two interfaces and weak bonding. In order to solve this problem, the corona method on the surface of the polymer film is usually used to increase the surface tension of the polymer film, thereby improving the bonding strength between the polymer film and the metal layer. However, this method has the following shortcomings: (1) Under the premise of ensuring that the mechanical properties of the polymer film do not change significantly, the surface tension of the polymer film after corona treatment is generally 35-50mN/m. Compared with the polymer before treatment, The surface tension of the membrane (25~35mN/m) has limited improvement, and there is still a large gap with the surface tension of the metal layer (more than 100mN/m), resulting in an unsatisfactory combination between the two; (2 ) The surface tension of the polymer film after corona treatment is unstable. After being stored for a period of time, the surface tension decreases, and finally it is close to the surface tension of the polymer film before treatment, which means there is a problem of unstable storage.

This application creatively proposes a modified polymer film from the perspective of surface modification treatment. A surface modification layer is formed on one or both sides of the polymer base film through plasma polymerization. The resulting modification The surface polarity of the polymer film is significantly increased, and the corresponding surface tension is also significantly increased. The surface tension of the modified polymer film is stable for a long time, which can effectively promote the strong bonding between the polymer base film and the metal layer. Therefore, using the modified polymer film as a base film to prepare a metallized polymer film can effectively solve the problem of weak bonding between the modified polymer film and the metal layer.

In some embodiments, the reaction raw materials of the surface modification layer include one of acrylic acid, acrylonitrile, allylamine, ethylenediamine, n-propylamine, methacrylic acid, methyl methacrylate, and their derivatives and copolymers. or more.

It can be understood that the reaction raw materials of the surface modification layer include, but are not limited to, any of acrylic acid, acrylonitrile, allylamine, ethylenediamine, n-propylamine, methacrylic acid, methyl methacrylate, and their derivatives and copolymers. One, or the reaction raw materials of the surface modification layer include but are not limited to any of acrylic acid, acrylonitrile, allylamine, ethylenediamine, n-propylamine, methacrylic acid, methyl methacrylate, and their derivatives and copolymers. A mixture of several types in any proportion.

In some embodiments, the material of the polymer-based film includes polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate ( PBT), polyethylene naphthalate (PEN), polyimide (PI), polypropylene, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), poly One or more of phenylene sulfide (PPS), polyphenylene ether (PPO), polystyrene (PS), polyamide, polyimide and their derivatives.

It can be understood that the materials of the polymer-based film include but are not limited to polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyimide (PI), polypropylene, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), Any one of polyphenylene sulfide (PPS), polyphenylene ether (PPO), polystyrene (PS), polyamide, polyimide and their derivatives, or the material of the polymer base film includes But not limited to polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate ( PEN), polyimide (PI), polypropylene, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyphenylene ether (PPO) ), polystyrene (PS), polyamide, polyimide and their derivatives in any proportion of the mixture.

In some embodiments, the thickness of the polymer base film is 1 μm or more.

It can be understood that the thickness of the polymer base film is 1 μm or greater than 1 μm, including but not limited to any value between 1 and 20 μm. For example, the thickness of the polymer base film can be 1 μm, 2 μm, 3 μm, 4 μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm. Considering the use, production cost and stability, the thickness of the polymer base film can be 2 to 20 μm.

It can be understood that the thickness of the surface modification layer can be any value between 5 and 200nm. For example, the thickness of the surface modification layer can be 5nm, 7nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm. The function of the surface modification layer in this application is to improve the surface properties (surface tension) of the polymer base film. Under the premise of uniform modification, increasing the thickness of the surface modification layer will not further improve the surface properties, and it will also increase the number of raw materials. cost. In addition, taking into account the ease of production and operation, the thickness of the surface modification layer can be 10 to 100 nm.

Another aspect of the present application provides a method for preparing the above-mentioned modified polymer film. The preparation method includes the following steps: performing plasma polymerization modification on the surface of the polymer-based film to form at least one surface thereof. Surface modification layer.

In some embodiments, when performing plasma polymerization modification on the surface of the polymer base film, a mixed gas composed of oxygen and argon and reaction raw materials are introduced;

The mixed gas bombards the surface of the polymer-based film to provide reactive sites, and the reaction raw materials are grafted onto the surface of the polymer-based film through the reactive sites, thereby forming a surface modification layer.

It should be explained that the oxygen used in this application is used to generate oxygen plasma and bombard the polymer base film, thereby providing active sites for graft modification reactions. The role of argon gas is to generate argon plasma and bombard the polymer polymerization reaction. The surface of the polymer base film is roughened and the reaction raw materials are grafted onto the surface of the polymer base film through the reaction active sites, thereby forming a surface modification layer. The surface polarity of the modified polymer film prepared by this preparation method is significantly improved, and the corresponding surface tension is also significantly increased. Moreover, the surface tension of the modified polymer film is stable for a long time, which can effectively promote the interaction between the polymer base film and the metal. The layers are firmly bonded.

In some embodiments, the plasma polymerization device includes two copper electrodes. Optionally, the distance between the two copper electrodes is 5 to 20 cm. Depending on the effect, the distance between the two copper electrodes may be 8 to 15 cm.

It can be understood that the frequency of the radio frequency power supply can be any value between 3 and 30 MHz. For example, the frequency of the radio frequency power supply can be 3 MHz, 5 MHz, 8 MHz, 10 MHz, 14 MHz, 18 MHz, 20 MHz, 23 MHz, 26 MHz, and 30 MHz. Depending on the effect, the frequency of the RF power supply can be 10 to 20MHz. The power of the plasma polymerization device can be any value between 10 and 50W. For example, the power of the plasma polymerization device can be 10W, 15W, 20W, 25W, 30W, 35W, 40W, 45W, and 50W. Depending on the effect, the power of the plasma polymerization device can be 20 to 40W. When the power of the plasma polymerization device is too low, the reaction rate is too low. When the power is too high, the reaction is too fast, resulting in uneven surface modification layers.

In some embodiments, the flow ratio of oxygen and argon is (40% to 80%): (60% to 20%).

Under normal working conditions, the vacuum pump of the plasma polymerization device of the present application can adjust the reaction pressure by adjusting the gas flow. Specifically: first introduce oxygen and argon, and control the flow of the two to achieve the pressure in the plasma polymerization device. Maintain it at a certain value between 10 and 30 mTorr, then introduce the reaction raw materials, and control the flow rate of the reaction raw materials to maintain the pressure in the plasma polymerization device at a certain value between 30 and 50 mTorr. If the pressure in the plasma polymerization device is too low or too high, the reaction activity will be reduced.

In some embodiments, the reaction time of plasma polymerization modification is 1 to 60 minutes.

The reaction time of plasma polymerization modification can be any value between 1 and 60 minutes. For example, the reaction time of plasma polymerization modification can be 1min, 5min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min.

In the preparation method of the modified polymer film mentioned above, parameters such as the reaction time of plasma polymerization modification, the power of the radio frequency power supply of the plasma polymerization device, the reaction raw materials and the material of the polymer base film can be adjusted, thereby effectively improving the The surface tension of the modified polymer film and the adhesion between the modified polymer film and the metal layer.

Another aspect of the present application provides a metallized polymer film. The metalized polymer film includes a metal layer and the above-mentioned modified polymer film or the modified polymer film produced by the above-mentioned preparation method. The metal layer is located on the modified polymer film. on at least one surface modification layer of the material film;

In some embodiments, the preparation method of the metal layer includes one or more of physical vapor deposition, electroplating, and chemical plating, wherein the physical vapor deposition method includes but is not limited to resistance heating vacuum evaporation, electron beam Heating vacuum evaporation method, laser heating vacuum evaporation method and magnetron sputtering method.

Yet another aspect of the present application provides a composite current collector, which includes the metallized polymer film described above.

Considering the conductivity of the material and taking into account the cost, the material of the metal layer of the positive electrode composite current collector can be aluminum or aluminum alloy. The aluminum content in the aluminum alloy can be greater than or equal to 80wt%. Furthermore, the copper content can be greater than 90wt%. The negative electrode The material of the metal layer of the composite current collector may be copper or copper alloy. The copper content in the copper alloy may be greater than or equal to 80 wt%. Further, the copper content may be greater than 90 wt%.

In some embodiments, the composite current collector further includes a protective layer, which is disposed on the surface of the metal layer;

Optionally, the material of the protective layer includes 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 nanoparticles One or more of quantum dots, carbon nanotubes, carbon nanofibers and graphene;

Optionally, the thickness of the protective layer is 10-200nm;

Optionally, the thickness of the metal layer is 300-2000nm.

In some embodiments, the thickness of the protective layer ranges from 50 to 100 nm.

It can be understood that the protective layer provided in this application is used to prevent the metal layer from being chemically corroded or mechanically damaged. The materials of the protective layer include but are not limited to nickel, chromium, nickel-based alloys, copper-based alloys, copper oxide, aluminum oxide, and nickel oxide. , any one of chromium oxide, cobalt oxide, graphite, carbon black, acetylene black, Ketjen black, carbon nanometer quantum dots, carbon nanotubes, carbon nanofibers and graphene, or the material of the protective layer includes but is not limited to 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 A mixture obtained by mixing any kind of graphene in any proportion. The thickness of the protective layer can be any value between 10 to 200nm or 50 to 100nm. For example, the thickness of the protective layer can be 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm. The thickness of the metal layer is any value between 300-2000nm or 500-1000nm. For example, the thickness of the metal layer can be 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm. , 950nm, 1000nm, 1050nm, 1100nm, 1200nm, 1250nm, 1300nm, 1350nm, 1400nm, 1450nm, 1500nm, 1550nm, 1600nm, 1650nm, 1700nm, 1750nm, 1800nm, 1850 nm, 1900nm, 1950nm or 2000nm.

In some embodiments, the composite current collector includes two protective 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.

In some embodiments, the protective layer is prepared by a method including, but not limited to, one or more of physical vapor deposition, in-situ forming, and coating. Among them, the vapor deposition method can be one or more of the vacuum evaporation method and the magnetron sputtering method; the in-situ forming method can be a method of forming a metal oxide passivation layer in situ on the surface of the metal layer; the coating method It can be one or more of die coating, blade coating and extrusion coating.

It can be understood that the above-mentioned electrode pole piece may be a positive electrode pole piece or a negative electrode pole piece.

This application does not limit the above-mentioned electronic devices. The above-mentioned electronic devices may include but are not limited to mobile phones, desktop computers, notebook computers, smart home appliances, electric vehicles, electric bicycles, digital cameras, etc.

The present application will be further described in detail below in conjunction with specific examples and comparative examples. For experimental parameters not specified in the following specific examples, priority is given to the guidelines given in the application documents. You can also refer to experimental manuals in the field or other experimental methods known in the field, or refer to the experimental conditions recommended by the manufacturer. It can be understood that the instruments and raw materials used in the following examples are relatively specific, and in other specific examples, they may not be limited thereto.

Example 1

Material selection: The selected polymer base film is a commercial 6 μm biaxially stretched polypropylene (PP) film; the reaction raw material is acrylic acid, and the purity is analytical grade.

1. Preparation of modified polymer membrane

Place a PP film with a thickness of 6 μm in a plasma polymerization device, set the distance between copper electrodes to 10cm, set the power of the radio frequency power supply to 10W, and set the frequency to 15MHz;

Start the vacuum pump for vacuuming. After the internal pressure of the plasma polymerization device reaches 10mTorr, open the first gas source and introduce oxygen and argon. The flow ratio of the two is 70%:30%. By adjusting the The flow rate maintains the pressure inside the plasma polymerization device at 20mTorr. After the pressure stabilizes at 20mTorr, open the second gas source and introduce acrylic acid gas. By adjusting the flow rate of the acrylic acid gas, the pressure inside the plasma polymerization device is maintained at 40mTorr. ;

Start the RF power supply, start timing after the power and frequency are stable, and then start plasma polymerization modification. The reaction time is 5 minutes. After the reaction is completed, turn off the RF power supply, the first air source, the second air source and the vacuum pump, and wait until the internal After the air pressure reaches atmospheric pressure, take out the PP film, which is the modified polymer film.

2. Preparation of negative electrode composite current collector

2.1 Preparation of metal layer

The above-mentioned modified polymer film is placed in a vacuum evaporation chamber, and the high-purity copper wire (purity greater than 99.99%) in the metal evaporation chamber is melted and evaporated at a high temperature of 1400 to 2000°C. The evaporated metal atoms pass through the vacuum coating chamber The cooling system is deposited on both surfaces of the modified polymer film to form a copper metal layer with a thickness of 1 μm;

2.2 Preparation of protective layer

1g of graphene was evenly dispersed into 999g of nitrogen methylpyrrolidone (NMP) solution by ultrasonic dispersion, and a coating liquid with a solid content of 0.1wt% was prepared. The coating liquid was evenly coated through a die coating process. to the surface of the metal layer, where the coating amount is controlled to 80 μm, and then dried at 100°C to obtain a negative electrode composite current collector.

3. Preparation of positive electrode composite current collector

3.1 Preparation of metal layer

The above-mentioned modified polymer film is placed in a vacuum evaporation chamber, and the high-purity aluminum wire (purity greater than 99.99%) in the metal evaporation chamber is melted and evaporated at a high temperature of 1300 to 2000°C. The evaporated metal atoms pass through the vacuum coating chamber The cooling system is deposited on both surfaces of the modified polymer to form an aluminum metal layer with a thickness of 1 μm;

3.2 Preparation of protective layer

1g of carbon nanotubes was evenly dispersed into 999g of nitrogen methylpyrrolidone (NMP) solution by ultrasonic dispersion, and a coating liquid with a solid content of 0.1wt% was prepared. The coating liquid was evenly coated through a die coating process. Coated onto the surface of the metal layer, the coating amount is controlled at 90 μm, and then dried at 100°C to obtain a positive electrode composite current collector.

Example 2

It is basically the same as Example 1, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 10 minutes.

Example 3

It is basically the same as Example 1, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 20 minutes.

Example 4

It is basically the same as Example 1, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 30 minutes.

Example 5

It is basically the same as Example 1, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 50 minutes.

Example 6

It is basically the same as Example 1, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 1 minute.

Example 7

It is basically the same as Example 1, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 60 minutes.

Example 8

It is basically the same as Example 3, except that when preparing the modified polymer film, the power of the radio frequency power supply of the plasma polymerization device is 20W.

Example 9

It is basically the same as Example 3, except that when preparing the modified polymer film, the power of the radio frequency power supply of the plasma polymerization device is 30W.

Example 10

It is basically the same as Example 3, except that when preparing the modified polymer film, the power of the radio frequency power supply of the plasma polymerization device is 40W.

Example 11

It is basically the same as Example 9, except that when preparing the modified polymer film, the reaction raw material is allylamine.

Example 12

It is basically the same as Example 9, except that when preparing the modified polymer membrane, the reaction raw material is acrylonitrile.

Example 13

It is basically the same as Example 9, except that when preparing the modified polymer film, the reaction raw material is methacrylic acid.

Example 14

It is basically the same as Example 9, except that when preparing the modified polymer membrane, the reaction raw material is n-propylamine.

Example 15

It is basically the same as Example 9, except that when preparing the modified polymer film, the reaction raw material is methyl methacrylate.

Example 16

It is basically the same as Example 9, except that when preparing the modified polymer membrane, the reaction raw material is ethylenediamine.

Example 17

It is basically the same as Example 9, except that when preparing the modified polymer film, the polymer base film is a 6 μm biaxially stretched PET film.

Comparative example 1

It is basically the same as Example 9, except that the polymer base film (PP film) is not modified.

Comparative example 2

Basically the same as Example 9, the difference is that the surface modification layer is formed by a traditional corona modification method, which specifically includes the following steps: placing a PP film with a thickness of 6 μm in a roll-to-roll corona treatment device, The corona power is selected to be 10kW, the current is selected to be 6A, and the surface of the PP film is modified at a linear speed of 50m/min.

Comparative example 3

It is basically the same as Example 9, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 0.5 min.

Comparative example 4

It is basically the same as Example 9, except that when preparing the modified polymer membrane, the reaction time of plasma polymerization modification is 62 minutes.

Comparative example 5

It is basically the same as Example 9, except that when preparing the modified polymer film, the power of the radio frequency power supply of the plasma polymerization device is 5W.

Comparative example 6

It is basically the same as Example 9, except that when preparing the modified polymer film, the power of the radio frequency power supply of the plasma polymerization device is 60W.

Test Example 1 Surface Tension and Adhesion Test

Conduct surface tension tests on the modified polymer films prepared in Examples 1 to 15 and Comparative Examples 1 to 6, and conduct surface tension tests on the modified polymer films prepared in Examples 1 to 15 and Comparative Examples 1 to 6 for positive electrode composite current collectors and negative electrode composites. The current collector was tested for adhesion, and the test results are shown in Table 1. The test method is as follows:

1. Surface tension test

Refer to GB/T 14216-2008, conduct a surface tension test on the modified polymer film; test the surface tension of the newly prepared modified polymer film, that is, the initial surface tension, and place the prepared modified polymer film for three months, and then test its surface tension.

2. Adhesion test

Bond a layer of Permacel P-94 double-sided tape on a 1mm thick aluminum foil, bond the positive electrode/negative electrode composite current collector on top of the double-sided tape, and cover it with a layer of ethylene acrylic acid copolymer on top of the positive electrode composite current collector/negative electrode composite current collector. material film (DuPont Nurcel0903, thickness 50 μm), then hot-pressed at 1.3×10 ⁵ N/m ² and 120°C for 10 s, cooled to room temperature, cut into small strips of 150 mm×15 mm, and the ethylene acrylic acid copolymer of the small strips The film is fixed on the upper clamp of the tensile machine, and the remaining part is fixed on the lower clamp. After being fixed, the two are peeled off at an angle of 180° and a speed of 100mm/min. The peeling force tested is the adhesion between the modified polymer film and the metal layer. Knot strength.

Table 1 Surface tension and adhesion test results

It can be seen from Table 1 that compared with Comparative Examples 1 to 2, the surface tension of the modified polymer film of Example 9 is significantly improved, and after being left for three months, the surface tension of the modified polymer film is basically unchanged and stable. The property is significantly improved, and at the same time, the adhesion between the modified polymer film and the metal layer in the positive electrode composite current collector and negative electrode composite current collector of Example 8 is also significantly improved, indicating that the plasma polymerization method provided by the present application can effectively improve the polymer base film. The surface tension and stability of the modified polymer film prepared by forming a surface modification layer on the surface are significantly improved, and the adhesion between the modified polymer film and the surface metal layer is also significantly improved;

Observing Examples 1 to 7 and Comparative Examples 3 to 4, it was found that the surface tension of the modified polymer films of Example 4, Example 5 and Example 7 was relatively high, and the modified positive electrode composite current collector and negative electrode composite current collector The bonding force between the polymer film and the metal layer is also relatively high, indicating that the reaction time of plasma polymerization modification is more important when preparing a modified polymer film;

Observing Example 3, Examples 8-10 and Comparative Examples 5-6, it was found that the surface tension of the modified polymer films of Examples 9-10 was relatively high, and the modified polymers in the positive electrode composite current collector and the negative electrode composite current collector The bonding force between the film and the metal layer is also relatively high, indicating that when preparing modified polymer films, the power of the radio frequency power supply of the plasma polymerization device has a great impact on the modification effect. The power of the radio frequency power supply of the plasma polymerization device is too high. When the polymerization reaction is too fast, it is easy to cause uneven reaction.

The technical features of the above-described embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, All should be considered to be within the scope of this manual.

The above-described embodiments only express several implementation modes of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all fall within the protection scope of the present application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

A modified polymer film, characterized by comprising a polymer base film and a surface modification layer, the surface modification layer being formed on at least one surface of the polymer base film by a plasma polymerization method .
The modified polymer film according to claim 1, wherein the reaction raw materials of the surface modification layer include acrylic acid, acrylonitrile, allylamine, ethylenediamine, n-propylamine, methacrylic acid, methacrylic acid methyl One or more of esters and their derivatives and copolymers.
The modified polymer film according to any one of claims 1 to 2, characterized in that the material of the polymer base film includes polypropylene, polyethylene, polyethylene terephthalate, polyethylene terephthalate, Butylene terephthalate, polyethylene naphthalate, polyimide, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, polyphenylene ether, poly One or more of styrene, polyamide, polyimide and their derivatives.
The modified polymer film according to any one of claims 1 to 3, wherein the thickness of the polymer base film is 1 μm or more.
The modified polymer film according to any one of claims 1 to 4, characterized in that the thickness of the surface modification layer is 5 to 200 nm.
The method for preparing a modified polymer film according to any one of claims 1 to 5, characterized in that it includes the following steps: performing plasma polymerization modification on the surface of the polymer-based film to At least one surface forms the surface modification layer.
The preparation method according to claim 6, characterized in that when performing plasma polymerization modification on the surface of the polymer base film, a mixed gas composed of oxygen and argon and reaction raw materials are introduced;

The mixed gas bombards the surface of the polymer base film to provide reactive sites, and the reaction raw materials are grafted to the surface of the polymer base film through the reactive sites, thereby forming the reaction active sites. The surface modification layer.
The preparation method according to any one of claims 6 to 7, characterized in that a plasma polymerization device is used to perform plasma polymerization modification on the surface of the polymer base film;

The plasma polymerization device includes a radio frequency power supply, the frequency of the radio frequency power supply is 3 to 30 MHz; the power of the plasma polymerization device is 10 to 50 W.
The preparation method according to any one of claims 6 to 8, characterized in that the reaction time of the plasma polymerization modification is 1 to 60 minutes.
A metallized polymer film, characterized in that it includes a metal layer and the modified polymer film according to any one of claims 1 to 5 or the modified polymer film prepared by the preparation method according to any one of claims 6 to 9. a modified polymer film, the metal layer is located on at least one surface modification layer of the modified polymer film;

Optionally, the material of the metal layer includes one or more of copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, titanium and silver.
A composite current collector, characterized by comprising the metallized polymer film according to claim 10.
The composite current collector according to claim 11, further comprising a protective layer disposed on the surface of the metal layer;

Optionally, the material of the protective layer includes 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, One or more of carbon nanoquantum dots, carbon nanotubes, carbon nanofibers and graphene;

Optionally, the thickness of the protective layer is 10-200nm;

Optionally, the thickness of the metal layer is 300-2000 nm.
An electrode pole piece, characterized in that it includes the composite current collector according to claim 11 or 12.
A battery, characterized in that it includes the electrode pole piece according to claim 13.
An electronic device, characterized by comprising the battery according to claim 14.