An encapsulation film, its preparation method, electrochemical device, and terminal equipment.

Abstract

This disclosure relates to an encapsulation film, its preparation method, and an electrochemical device. The encapsulation film includes a nylon surface layer, which comprises a nylon base layer and a modified coating on the surface of the nylon base layer. The contact angle of the nylon surface layer with respect to a deionized aqueous solvent is no greater than 85°. A battery cell encapsulated with the encapsulation film of this disclosure can maintain adhesion to an aluminum layer during heating and pressurization. This battery cell is not easily detached from the mobile phone during extreme testing and can ensure the normal charging and discharging capability of the mobile phone.

Description

Technical Field

[0001] This disclosure belongs to the field of power supply technology, specifically relating to an encapsulation film, its preparation method, and an electrochemical device. Background Technology

[0002] With the rapid expansion of the power market, the supply of encapsulation film materials is approaching saturation; there is a serious shortage in the supply of digital materials, necessitating the development of self-developed encapsulation film technology to ensure the consumer market.

[0003] Batteries play a crucial role in the charging and discharging of terminal devices, while the encapsulation film is the path connecting the battery and the terminal device. If the surface of the encapsulation film, such as aluminum-plastic film, peels off, it can cause misprinting during the battery screen printing process, which is not conducive to product traceability. At the same time, the encapsulation films such as aluminum-plastic film in related technologies are easy to tear off and have weak adhesion. As a result, during the use of mobile phones (especially in extreme environments such as drops / rolling), the battery is easy to detach from the battery compartment of the terminal device, which will render the terminal device unusable. Summary of the Invention

[0004] The purpose of this disclosure is to provide an encapsulation film that is highly compatible with the battery compartment of a terminal device and whose surface layer is not easily detached.

[0005] To achieve the above objectives, a first aspect of this disclosure provides an encapsulation film comprising a nylon surface layer, the nylon surface layer including a nylon base layer and a modified coating covering the surface of the nylon base layer, the contact angle of the nylon surface layer with respect to a deionized water solvent being no greater than 85°.

[0006] Optionally, the contact angle of the nylon surface layer with respect to the deionized water solvent is 65-83°.

[0007] Optionally, the thickness of the nylon surface layer is 10-30 μm; the thickness of the modified coating is 0.1-10 μm.

[0008] Optionally, the thickness of the nylon surface layer is 15-25 μm; the thickness of the modified coating is 0.1-2 μm.

[0009] Optionally, the modified coating comprises a first polymer matrix and modified particles doped in the first polymer matrix, wherein the modified particles are inorganic particles whose surface has been modified with polar functional groups.

[0010] Optionally, the amount of modified particles added is 1-20% by weight, based on the total mass of the material of the modified coating; the particle size of the modified particles is 1-1000 nm.

[0011] Optionally, the amount of modified particles added is 1-10% based on the total mass of the material of the modified coating; the particle size of the modified particles is 100-500 nm.

[0012] Optionally, the material of the first polymer matrix is ​​selected from at least one of acrylic resin, polyacrylic acid, polyurethane, polyvinyl alcohol, epoxy resin and epoxy resin derivatives; the inorganic particles are selected from at least one of silicon dioxide, aluminum oxide, magnesium hydroxide, barium sulfate and boehmite; and the polar functional groups are selected from at least one of hydroxyl, carboxyl, ester and cyano groups.

[0013] Optionally, the material of the first polymer matrix is ​​a mixture of polyacrylic acid and epoxy resin; the inorganic particles are boehmite and / or aluminum oxide.

[0014] Optionally, the modified particles are obtained by washing and drying the first material with an organic solvent; the first material is obtained by refluxing a mixture of the inorganic particles and the modified solvent in a first solvent.

[0015] Optionally, the modified solvent is selected from C4-C4. 20 alcohols, C3-C 20 The first solvent is selected from at least one of organic unsaturated acids, acrylic solvents, and nitrile solvents; the first solvent is selected from at least one of aromatic solvents, acrylic solvents, aramid solvents, and amide solvents.

[0016] Optionally, the modified solvent is selected from at least one of butanol, isobutanol, stearic acid, acrylic acid, methyl methacrylate and acrylonitrile; the first solvent is selected from at least one of toluene, p-toluene, methyl methacrylate, aramid and acetamide.

[0017] Optionally, the encapsulation film further includes an aluminum core layer and a resin layer; the aluminum core layer covers the surface of the resin layer, and the nylon surface layer is formed on the surface of the aluminum core layer; optionally, the thickness of the resin layer is 30-50% of the total thickness of the encapsulation film, the thickness of the nylon surface layer is 10-20% of the total thickness of the encapsulation film, and the thickness of the aluminum core layer is 13-18% of the total thickness of the encapsulation film.

[0018] Optionally, the material of the resin layer is selected from at least one of acrylic acid, polyurethane, styrene-acrylic resin, epoxy resin, and polyvinylidene fluoride.

[0019] The second part of this disclosure provides a method for preparing an encapsulation film, the method comprising:

[0020] The modified particles are dispersed in a first polymer matrix material after centrifugation to obtain a modified coating material;

[0021] The modified coating material is applied to the surface of the nylon base layer to obtain the nylon surface layer;

[0022] An aluminum core layer is coated onto the surface of a resin layer to obtain an aluminum composite layer;

[0023] The nylon surface layer is coated onto the surface of the aluminum composite layer to obtain an encapsulation film;

[0024] The contact angle of the nylon surface layer with respect to the deionized water solvent is no greater than 85°.

[0025] Optionally, the material of the first polymer matrix is ​​selected from at least one of acrylic resin, polyacrylic acid, polyurethane, polyvinyl alcohol, epoxy resin, and epoxy resin derivatives.

[0026] Optionally, the modified particles are inorganic particles whose surface has been modified with polar functional groups; the inorganic particles are selected from at least one of silicon dioxide, aluminum oxide, magnesium hydroxide, barium sulfate and boehmite, and the polar functional groups are selected from at least one of hydroxyl, carboxyl, ester and cyano groups.

[0027] Optionally, the method for preparing the modified particles includes: mixing inorganic particles with a modifying solvent and then refluxing the mixture in a first solvent to obtain a first material; filtering the first material, washing it with an organic solvent, and then drying it.

[0028] Optionally, the modified solvent is selected from at least one of butanol, isobutanol, stearic acid, acrylic acid, methyl methacrylate, and acrylonitrile; the first solvent is selected from at least one of toluene, p-toluene, acrylic acid, aramid, and amide.

[0029] Optionally, the reflux conditions include a temperature of 20-40℃ and a time of 2-6 hours; the drying conditions include a temperature of 60-90℃ and a time of 10-16 hours.

[0030] Optionally, the method further includes: coating an aluminum core layer onto the surface of a resin layer to obtain an aluminum composite layer; and coating the surface of the aluminum composite layer with a nylon surface layer to obtain an encapsulation film.

[0031] A third aspect of this disclosure provides an electrochemical device comprising a battery cell encapsulated by an encapsulation film, said encapsulation film being the aforementioned encapsulation film or an encapsulation film prepared by the aforementioned method.

[0032] A fourth aspect of this disclosure provides a terminal device, the terminal device including an electrochemical device, the electrochemical device being the aforementioned electrochemical device.

[0033] Through the above technical solution, the encapsulation film disclosed herein includes a nylon surface layer with a modified coating, and the contact angle of the nylon surface layer relative to the deionized water solvent is not greater than 85°. The battery cell encapsulated by the encapsulation film disclosed herein can maintain adhesion to the aluminum layer during heating and pressurization. The battery cell is not easy to fall off the mobile phone during extreme testing and can ensure the normal charging and discharging capability of the mobile phone.

[0034] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is a schematic diagram of a nylon surface layer in an exemplary embodiment of the present disclosure;

[0037] Figure 2 This is a schematic diagram of an encapsulation film according to an exemplary embodiment of the present disclosure.

[0038] Explanation of reference numerals in the attached figures

[0039] 1. Nylon surface layer; 2. Modified coating; 3. Nylon base layer

[0040] 4. Aluminum core layer; 5. Resin layer Detailed Implementation

[0041] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0042] The contact angle measurement method in this disclosure refers to measuring the contact angle of the deionized water on the surface of the object to be tested within 50 seconds after adding 2 microliters of deionized water droplets to the surface of the object to be tested.

[0043] A first aspect of this disclosure provides an encapsulation film including a nylon surface layer comprising a nylon base layer and a modified coating covering the surface of the nylon base layer, the nylon surface layer having a contact angle with respect to a deionized water solvent of no more than 85°.

[0044] For example, the encapsulation film can be an aluminum-plastic film.

[0045] The inventors of this disclosure have discovered that setting the contact angle of the nylon surface layer relative to the deionized water solvent to no more than 85° can ensure the adhesion of the encapsulation film surface layer, preventing the battery from falling out of the phone compartment and thus improving the safety of the phone during use.

[0046] For example, when the contact angle of the nylon surface layer with respect to the deionized water solvent is 65-83°, the encapsulation film of this disclosure has excellent surface adhesion when applied to the outer encapsulation of the battery cell.

[0047] According to this disclosure, the thickness of the nylon surface layer can be 10-30 μm; the thickness of the modified coating can be 0.1-10 μm.

[0048] The thickness of the nylon surface layer is 15-25 μm; the thickness of the modified coating is 0.1-2 μm.

[0049] In an exemplary embodiment, the modified coating comprises a first polymer matrix and modified particles doped into the first polymer matrix, wherein the modified particles are inorganic particles whose surface has been modified with polar functional groups. Figure 1 As shown, the nylon surface layer of the encapsulation film of this disclosure comprises a nylon base layer 3 and a modified coating 2 covering the surface of the nylon base layer, and the modified coating is doped with modified particles. A battery cell encapsulated using the encapsulation film of this disclosure can maintain adhesion to the aluminum layer during heating and pressurization. This battery cell is not easily detached from the mobile phone during extreme testing and can ensure the normal charging and discharging capability of the mobile phone.

[0050] According to this disclosure, based on the total mass of the material of the modified coating, the amount of the modified particles added can be 1-20% by weight; the particle size of the modified particles can be 1-1000 nm.

[0051] In an exemplary embodiment, the amount of modified particles added is 1-10% based on the total mass of the material of the modified coating; the particle size of the modified particles is 100-500 nm.

[0052] According to this disclosure, the material of the first polymer matrix may be selected from at least one of acrylic resin, polyacrylic acid, polyurethane, polyvinyl alcohol, epoxy resin and epoxy resin derivatives.

[0053] According to this disclosure, the inorganic particles may be selected from at least one of silicon dioxide, aluminum oxide, magnesium hydroxide, barium sulfate, and boehmite; the polar functional groups may be selected from at least one of hydroxyl, carboxyl, ester, and cyano groups.

[0054] In an exemplary embodiment, the material of the first polymer matrix is ​​a mixture of polyacrylic acid and epoxy resin; the inorganic particles are boehmite and / or aluminum oxide.

[0055] The method for preparing the nylon surface layer disclosed herein can, for example, involve uniformly dispersing inorganic particles in a first polymer matrix material after centrifugation, and then uniformly coating them onto the surface layer of an aluminum core using dip coating or gravure coating.

[0056] According to this disclosure, the modified particles are obtained by washing and drying a first material with an organic solvent; the first material is obtained by reflux of a mixture of the inorganic particles and the modifying solvent in a first solvent; optionally, the modifying solvent is selected from C4-C. 20 alcohols, C3-C 20The modified solvent is selected from at least one of organic unsaturated acids, acrylic solvents, and nitrile solvents; the first solvent is selected from at least one of aromatic solvents, acrylic solvents, aramid solvents, and amide solvents. For example, the modified solvent may be selected from at least one of butanol, isobutanol, stearic acid, acrylic acid, methyl methacrylate, and acrylonitrile; the first solvent may be selected from at least one of toluene, p-toluene, methyl methacrylate, aramid solvents, and acetamide. The organic solvent may be selected from alcohols and / or carboxylic acids. For example, the organic solvent may be selected from at least one of ethanol, glycerol, ethylene glycol, and oxalic acid.

[0057] In an exemplary embodiment, such as Figure 2 As shown, the encapsulation film may further include an aluminum core layer 4 and a resin layer 5; the aluminum core layer 4 covers the surface of the resin layer 5, and the nylon surface layer 1 is formed on the surface of the aluminum core layer 4; the aluminum core layer 4, resin layer 5, and nylon surface layer 2 of this disclosure can be prepared into an encapsulation film material by a dry method or a thermal method; optionally, the thickness of the resin layer 5 can be 30-50% of the total thickness of the encapsulation film, the thickness of the nylon surface layer 2 can be 10-20% of the total thickness of the encapsulation film, and the thickness of the aluminum core layer 4 can be 30-60% of the total thickness of the encapsulation film.

[0058] According to this disclosure, the material of the resin layer may be selected from at least one of acrylic acid, polyurethane, styrene-acrylic resin, epoxy resin and polyvinylidene fluoride.

[0059] The second part of this disclosure provides a method for preparing an encapsulation film, the method comprising:

[0060] The modified particles are dispersed in a first polymer matrix material after centrifugation to obtain a modified coating material;

[0061] The modified coating material is applied to the surface of the nylon base layer to obtain the nylon surface layer;

[0062] An aluminum core layer is coated onto the surface of a resin layer to obtain an aluminum composite layer;

[0063] The nylon surface layer is coated onto the surface of the aluminum composite layer to obtain an encapsulation film;

[0064] The contact angle of the nylon surface layer with respect to the deionized water solvent is no greater than 85°.

[0065] According to this disclosure, the material of the first polymer matrix may be selected from at least one of acrylic resin, polyacrylic acid, polyurethane, polyvinyl alcohol, epoxy resin and epoxy resin derivatives.

[0066] According to this disclosure, the modified particles can be inorganic particles whose surface has been modified with polar functional groups; the inorganic particles are selected from at least one of silicon dioxide, aluminum oxide, magnesium hydroxide, barium sulfate, and boehmite, and the polar functional groups are selected from at least one of hydroxyl, carboxyl, ester, and cyano groups. In an exemplary embodiment, based on the total mass of the modified coating material, the mass of the modified particles added can be 1-10% by weight; the particle size of the modified particles can be 100-500 nm.

[0067] According to this disclosure, the method for preparing the modified particles may include: mixing inorganic particles with a modifying solvent and then refluxing the mixture in a first solvent to obtain a first material; filtering the first material and then washing it with an organic solvent and drying it.

[0068] According to this disclosure, the modified solvent is selected from C4-C4. 20 alcohols, C3-C 20 The first solvent is selected from at least one of organic unsaturated acids, acrylic solvents, and nitrile solvents; the first solvent is selected from at least one of aromatic solvents, acrylic solvents, aramid fibers, and amides. For example, the modified solvent may be selected from at least one of butanol, isobutanol, stearic acid, acrylic acid, methyl methacrylate, and acrylonitrile; the first solvent may be selected from at least one of toluene, p-toluene, acrylic acid, aramid fibers, and amides.

[0069] The organic solvents used for washing in this disclosure may be selected from alcohols and / or carboxylic acids. For example, the organic solvent may be selected from at least one of ethanol, glycerol, ethylene glycol, and oxalic acid.

[0070] According to this disclosure, the method may further include: coating an aluminum core layer onto the surface of a resin layer to obtain an aluminum composite layer; and coating the surface of the aluminum composite layer with the nylon surface layer to obtain an encapsulation film.

[0071] A third aspect of this disclosure provides an electrochemical device comprising a battery cell encapsulated by an encapsulation film, said encapsulation film being the aforementioned encapsulation film or an encapsulation film prepared by the aforementioned method.

[0072] The manufacturing process of the electrochemical device disclosed herein is as follows: a cathode electrode, a separator, and an anode electrode can be wound to form a bare battery cell; an encapsulation film is stamped to form a shell to encapsulate the bare battery cell to form a dry battery cell; and the encapsulated dry battery cell is injected with liquid, hot-pressed to form a finished battery cell.

[0073] A fourth aspect of this disclosure provides a terminal device, the terminal device including an electrochemical device, the electrochemical device being the aforementioned electrochemical device.

[0074] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0075] Example 1

[0076] In this embodiment, the preparation method of the modified particles includes: mixing aluminum oxide particles with methyl methacrylate solvent to obtain a mixture; refluxing the mixture in acetamide solvent to obtain a first material; filtering the first material, washing it with ethanol solvent, and drying it to obtain ester-modified aluminum oxide particles. The reflux conditions include a temperature of 30°C and a time of 4 hours; the drying conditions include a temperature of 80°C and a time of 6 hours. The prepared modified particles are centrifuged and uniformly dispersed in a first polymer matrix material PET to obtain a coating material. The amount of modified particles added is 10% based on the total mass of the coating material. The prepared coating material is uniformly coated onto the surface of the aluminum core using a dip-coating method to obtain the nylon surface layer of this embodiment. A contact angle test was performed on the nylon surface layer of this embodiment, and the measured contact angle was 85°.

[0077] Example 2

[0078] In this embodiment, the preparation method of the modified particles includes: mixing boehmite oxide particles with an acrylic acid-modified solvent to obtain a mixture; refluxing the mixture in toluene solvent to obtain a first material; filtering the first material, washing it with glycerol solvent, and drying it to obtain carboxyl-modified boehmite oxide particles, wherein the reflux conditions include: temperature of 30°C and time of 4 hours; the drying conditions include: temperature of 80°C and time of 6 hours. The prepared modified particles are centrifuged and uniformly dispersed in a first polymer matrix material PT to obtain a coating material, wherein the amount of modified particles added is 5% based on the total mass of the coating material. The prepared coating material is uniformly coated onto the surface of an aluminum core by dip coating to obtain the nylon surface layer of this embodiment. A contact angle test was performed on the nylon surface layer of this embodiment, and the measured contact angle was 80°.

[0079] Example 3

[0080] In this embodiment, the preparation method of the modified particles includes: mixing silica oxide particles with an acrylonitrile-modified solvent to obtain a mixture; refluxing the mixture in an aramid solvent to obtain a first material; filtering the first material, washing it with ethyl acetate solvent, and drying it to obtain cyano-modified silica oxide particles. The reflux conditions include a temperature of 30°C and a time of 4 hours; the drying conditions include a temperature of 80°C and a time of 6 hours. The prepared modified particles are centrifuged and uniformly dispersed in a first polymer matrix material PET to obtain a coating material. The amount of modified particles added is 3% based on the total mass of the coating material. The prepared coating material is uniformly coated onto the surface of an aluminum core using a dip-coating method to obtain the nylon surface layer of this embodiment. A contact angle test was performed on the nylon surface layer of this embodiment, and the measured contact angle was 75°.

[0081] Comparative Example 1

[0082] In this comparative example, the encapsulation film includes a thermoplastic resin layer, a protective layer, and an aluminum foil layer disposed between the thermoplastic resin layer and the protective layer; at least one of polyamide film and polyester film is selected as the protective layer of the encapsulation film; a polyolefin film is selected as the thermoplastic resin layer of the encapsulation film; the surface of the aluminum foil layer is passivated; the aluminum foil layer and the protective layer are bonded together with polyurethane adhesive, and the aluminum foil layer and the thermoplastic resin layer are bonded together with acrylic adhesive. A contact angle test was performed on the protective layer of this comparative example, and the measured contact angle was 90°.

[0083] Test Example 1

[0084] The encapsulation films prepared in Examples 1-3 and Comparative Example 1 were tested, and the specific results are shown in Table 1.

[0085] The ink transfer printing test method is as follows: ink is transferred onto the surface of the packaging film, and 3M tape is used to stick the tape to the transfer printing area. Then, a 2kg roller is used to roll the tape back and forth at a constant speed for 30 times in each of the three areas. Finally, one end of the tape is lifted and the tape is quickly peeled off at a 45° angle to the test surface. If the transfer printing on the packaging film is clear, the test is considered passed; otherwise, the ink transfer printing test fails.

[0086] The test method for the adhesive strength of easy-tear stickers is as follows: cut double-sided tape into 50mm*65mm pieces, use a scraper to stick the double-sided tape to a steel plate, peel off the backing of the easy-tear sticker, stick the adhesive side to the surface of the double-sided tape, and smooth the surface with a pressure roller to ensure that the sample and the double-sided tape are completely bonded without air bubbles. Then, use a peel tester to pull it up at a speed of 300mm / min at 180°, and record the average length of the stable range of the curve.

[0087] The method for testing the extreme drop of a mobile phone is as follows: the battery is fixed in the phone compartment and kept in standby mode. The drop height is set to 1-2m. One round of drops is completed in the order of bottom / front / right / back / front / top / top left / top right / bottom right / bottom left. After the test, check the battery's fixation and confirm whether it has fallen out of the phone compartment.

[0088] The test method for the mobile phone extreme roller test is as follows: the battery is fixed in the mobile phone compartment and kept in standby mode. The rotation speed is set to 10-12 r / min. At the same time, it is ensured that the sample falls freely from the highest point. Every 10 times is one round. After the test, check the battery fixation and confirm whether it has fallen out of the mobile phone compartment.

[0089] The method for testing a phone's slight drop is as follows: Secure the battery in the phone compartment and keep it in standby mode. Set the drop height to 10-50cm and complete one round of drops in the following order: bottom / front / right / back / front / top / top left / top right / bottom right / bottom left. After the test, check the battery's secureness and confirm whether it has fallen out of the phone compartment.

[0090] Table 1

[0091]

[0092] As shown in Table 1, the surface contact angle of the encapsulation film in Examples 1-3 is no greater than 85°. The ink is free of padding, and the easy-tear adhesive strength is no less than 1.7 N / m, enabling it to pass the mobile phone extreme drop test, mobile phone extreme tumbling test, and mobile phone micro-drop test. Therefore, the battery cell encapsulated using the encapsulation film of this disclosure can maintain adhesion to the aluminum layer during heating and pressurization, and is not easily detached from the mobile phone, while ensuring the normal charging and discharging capability of the mobile phone.

[0093] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of this disclosure. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0094] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

[0095] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

Claims

1. An encapsulation film, characterized in that, The material includes a nylon surface layer comprising a nylon base layer and a modified coating covering the surface of the nylon base layer, wherein the contact angle of the nylon surface layer relative to a deionized aqueous solvent is not greater than 85º; wherein the modified coating comprises a first polymer matrix and modified particles doped in the first polymer matrix, wherein the modified particles are inorganic particles whose surface has been modified with polar functional groups; the amount of modified particles added is 1-20% by weight, based on the total mass of the material of the modified coating; the particle size of the modified particles is 1-1000 nm; the material of the first polymer matrix is ​​selected from at least one of acrylic resin, polyacrylic acid, polyurethane, polyvinyl alcohol, epoxy resin and epoxy resin derivatives; the inorganic particles are selected from at least one of silicon dioxide, aluminum oxide, magnesium hydroxide, barium sulfate and boehmite; the polar functional groups are selected from at least one of hydroxyl, carboxyl, ester and cyano groups.

2. The encapsulation film according to claim 1, wherein, The contact angle of the nylon surface layer with respect to the deionized water solvent is 65-83º.

3. The encapsulation film according to claim 1, wherein, The thickness of the nylon surface layer is 10-30µm; the thickness of the modified coating is 0.1-10µm.

4. The encapsulation film according to claim 3, wherein, The thickness of the nylon surface layer is 15-25µm; the thickness of the modified coating is 0.1-2µm.

5. The encapsulation film according to claim 1, wherein, Based on the total mass of the modified coating material, the amount of modified particles added is 1-10%; the particle size of the modified particles is 100-500 nm.

6. The encapsulation film according to claim 1, wherein, The first polymer matrix is ​​a mixture of polyacrylic acid and epoxy resin; the inorganic particles are boehmite and / or aluminum oxide.

7. The encapsulation film according to claim 1, wherein, The modified particles are obtained by washing and drying the first material with an organic solvent; the first material is obtained by refluxing the mixture of the inorganic particles and the modified solvent in the first solvent.

8. The encapsulation film according to claim 7, wherein, The modified solvent is selected from C4-C. 20 alcohols, C3-C 20 The first solvent is selected from at least one of organic unsaturated acids, acrylic solvents, and nitrile solvents; the first solvent is selected from at least one of aromatic solvents, acrylic solvents, and amide solvents.

9. The encapsulation film according to claim 8, wherein, The modified solvent is selected from at least one of butanol, isobutanol, stearic acid, acrylic acid, methyl methacrylate and acrylonitrile; the first solvent is selected from at least one of toluene, p-toluene, acrylic acid, aramid and acetamide.

10. The encapsulation film according to claim 1, wherein, The encapsulation film further includes an aluminum core layer and a resin layer; the aluminum core layer covers the surface of the resin layer, and the nylon surface layer is formed on the surface of the aluminum core layer.

11. The encapsulation film according to claim 10, wherein, The thickness of the resin layer is 30-50% of the total thickness of the encapsulation film, the thickness of the nylon surface layer is 10-20% of the total thickness of the encapsulation film, and the thickness of the aluminum core layer is 13-18% of the total thickness of the encapsulation film.

12. A method for preparing an encapsulation film, characterized in that, The method includes: The modified particles are dispersed in a first polymer matrix material after centrifugation to obtain a modified coating material; The modified coating material is applied to the surface of the nylon base layer to obtain the nylon surface layer; An aluminum core layer is coated onto the surface of a resin layer to obtain an aluminum composite layer; The nylon surface layer is coated onto the surface of the aluminum composite layer to obtain an encapsulation film; Wherein, the contact angle of the nylon surface layer relative to the deionized water solvent is not greater than 85º; the modified particles are inorganic particles whose surface has been modified with polar functional groups; based on the total mass of the modified coating material, the amount of the modified particles added is 1-20% by weight; the particle size of the modified particles is 1-1000 nm; the material of the first polymer matrix is ​​selected from at least one of acrylic resin, polyacrylic acid, polyurethane, polyvinyl alcohol, epoxy resin and epoxy resin derivatives; the inorganic particles are selected from at least one of silicon dioxide, aluminum oxide, magnesium hydroxide, barium sulfate and boehmite; and the polar functional groups are selected from at least one of hydroxyl, carboxyl, ester and cyano groups.

13. The method according to claim 12, wherein, The method for preparing the modified particles includes: The inorganic particles were mixed with the modified solvent and then refluxed in the first solvent to obtain the first material; The first material is filtered, washed with an organic solvent, and then dried.

14. The method according to claim 13, The modified solvent is selected from at least one of butanol, isobutanol, stearic acid, acrylic acid, methyl methacrylate and acrylonitrile; the first solvent is selected from at least one of toluene, p-toluene, acrylic acid, aramid and acetamide.

15. The method according to claim 13, wherein, The reflux conditions include a temperature of 20-40℃ and a time of 2-6 hours; the drying conditions include a temperature of 60-90℃ and a time of 4-12 hours.

16. An electrochemical device, characterized in that, The invention includes a battery cell encapsulated by an encapsulation film, wherein the encapsulation film is the encapsulation film according to any one of claims 1-11, or is the encapsulation film prepared by the method according to any one of claims 12-15.

17. A terminal device, characterized in that, The terminal device includes the electrochemical device as described in claim 16.

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