Normal-temperature bonding type coating diaphragm and preparation method thereof

Abstract

The invention relates to the field of battery diaphragms, and particularly discloses a normal-temperature bonding type coating diaphragm and a preparation method thereof. A normal-temperature bonding type coating diaphragm comprises a base film and a bonding coating located on at least one side of the base film, the bonding coating is formed by curing a bonding coating, and the bonding coating comprises the following raw materials: a binder, a thickening agent, isopropanol, an adhesive, a wetting agent and the balance of water; the binder is a binder particle with a core-shell structure, and the binder particle comprises a core material particle, a shell material particle and a cross-linking agent in a mass percentage ratio of (10-40%): (50-80%): 10%; the glass-transition temperature of the core material particles is-(30-50) DEG C, and the glass-transition temperature of the shell material particles is greater than or equal to 50 DEG C; the particle size of the core material particles is 0.8-10 [mu] m, and the particle size of the shell material particles is 200-400 nm. The diaphragm can be firmly bonded with an electrode plate at normal temperature, hot-pressing compounding is not needed, and the hot-pressing shrinkage risk of the diaphragm is reduced.

Description

Technical Field

[0001] This application relates to the technical field of lithium battery separators. More specifically, it relates to a room-temperature adhesive coating separator and a preparation method thereof. Background Art

[0002] As a clean secondary energy source, lithium-ion batteries have the advantages of high voltage, large energy, and fast charge and discharge, and are widely used in fields such as portable electronic communication products, electric vehicles, and energy storage.

[0003] As an isolation layer between the positive and negative electrode materials, the separator not only has tortuous and through microporous channels to provide a transmission path for lithium ions, but also separates the positive and negative electrodes to prevent short circuits or cause battery fires and explosions. It is one of the important components to provide safety protection for the battery core. As an important part of lithium-ion batteries, the properties of the separator directly determine the capacity, cycle performance, charge and discharge current density, and safety of the battery. Among them, the adhesion between the separator and the electrode sheet is also an important index to evaluate the quality of the separator, which directly affects the hardness and shape retention ability of the battery core.

[0004] Traditional adhesive separators are made of a base film and PVDF coated on the base film. However, PVDF does not have adhesion at room temperature. During the battery preparation process, it is usually necessary to hot-press the battery separator and the electrode sheet at a relatively high temperature to make the base film coated with PVDF closely adhere to the electrode sheet, that is, a bonding force can be formed with the electrode sheet only after applying a temperature of 80-90 °C, and the bonding force is generally low. However, if the adhesion performance of the separator film is not good, wrinkles are likely to form on the electrode sheet after hot pressing. At the same time, after the separator is hot-pressed, there is a risk of separator shrinkage, increasing the safety hazard of short circuit between the positive and negative electrodes of the battery, causing the battery to burn or even explode. At the same time, the positive electrode material of the battery may produce gas at a temperature of 80-90 °C, increasing the safety hazard.

[0005] In view of the above-related technologies, the inventor found that there is an urgent need to develop a separator that can have a strong adhesion to the electrode sheet at room temperature. Summary of the Invention

[0006] In order to reduce the risk of shrinkage during the hot pressing of the separator and increase the adhesion between the separator and the electrode sheet, this application provides a room-temperature adhesive coating separator and a preparation method thereof.

[0007] In the first aspect, this application provides a room-temperature adhesive coating separator, adopting the following technical solution: A room-temperature bonding type coating diaphragm, comprising a base film and a bonding coating located on at least one side of the base film, the bonding coating being formed by curing a bonding coating material, the bonding coating material comprising raw materials in the following weight percentages: 4-45% of a binder, 0.6-0.7% of a thickener, 0.4-0.6% of isopropanol, 4.5-5.5% of an adhesive, 0.1-0.12% of a wetting agent, and the balance being water; The binder is binder particles having a core-shell structure, and the binder particles having a core-shell structure contain core layer particles, shell layer particles and a cross-linking agent in a mass percentage of 10-40%:50-80%:10%; The glass transition temperature of the core layer particles is -(30 to 50)°C, and the glass transition temperature of the shell layer particles is ≥50°C; The particle size of the core layer particles is 0.8-10 μm, and the particle size of the shell layer particles is 200-400 nm.

[0008] By adopting the above technical solution, binder particles are formed by using shell layer particles with a high glass transition temperature and a small particle size and core layer particles with a low glass transition temperature and a large particle size. Through cross-linking polymerization, the shell layer particles provide protection for the core layer particles to prevent the core layer particles from contacting with other substances to form adhesion. After the binder particles are pressed, the core layer particles with a large particle size and a low glass transition temperature are deformed and extruded from the gaps formed by the shell layer particles to contact the electrode sheet, forming room-temperature bonding performance. It is not necessary to perform hot pressing under heating conditions, and room-temperature pressing can achieve bonding, reducing the influence of the hot pressing process on the battery cell and avoiding phenomena such as shrinkage and deformation of the diaphragm. At the same time, under the non-pressed state, the shell layer particles protect the core layer particles, and the bonding coating will not generate adhesion, which can prevent the diaphragm from generating winding adhesion at room temperature. In addition, after the core-shell structured binder particles are applied, the core layer particles are extruded from the gaps between the shell layer particles, forming a particle size match with the shell layer particles, obtaining better penetration pores, thereby improving the wettability of the electrolyte.

[0009] Optionally, the bonding coating material comprises raw materials in the following weight percentages: 6-15% of a binder, 0.65-0.7% of a thickener, 0.5-0.6% of isopropanol, 5-5.5% of an adhesive, 0.1-0.12% of a wetting agent, and the balance being water.

[0010] Optionally, the base film comprises a polypropylene base film with a thickness of 9 μm and a ceramic coating with a thickness of 2 μm that are laminated.

[0011] Optionally, the binder particles having a core-shell structure contain core layer particles, shell layer particles and a cross-linking agent in a mass percentage of 40%:50%:10%; The glass transition temperature of the core layer particles is -44.3 °C, and the glass transition temperature of the shell layer particles is 57.9 °C.

[0012] By adopting the above technical solution, core layer particles with a low glass transition temperature and shell layer particles with a high transition temperature are used. The two are crosslinked by a crosslinking agent, and the shell layer particles with a smaller particle size are coated around the core layer particles. After application, the core layer particles are extruded from the gaps between the shell layer particles, so as to achieve the bonding effect at room temperature.

[0013] Optionally, the D50 particle size of the core layer particles is 0.93 μm, and the D50 particle size of the shell layer particles is 200 nm.

[0014] By adopting the above technical solution, the shell layer particles and core layer particles with the above particle sizes cooperate with each other, and can form binder particles with a more uniform distribution of shell layer particles on the outer periphery of the core layer particles. At room temperature, no pressure is applied and no adhesiveness is generated, which can prevent adhesion during the winding of the separator.

[0015] Optionally, the core layer particles are selected from at least one of modified polystyrene, modified polyacrylic acid, modified polyacrylonitrile, modified acrylamide, and modified PVDF.

[0016] Optionally, the shell layer particles are selected from at least one of polystyrene, polyacrylic acid, polyacrylonitrile, and acrylamide.

[0017] Optionally, the crosslinking agent is selected from at least one of diacetone acrylamide, acetylacetoxyethyl methacrylate, N-methylol acrylamide, N-hydroxyethyl acrylamide, divinylbenzene, diallyl phthalate, and trimethylolpropane triacrylate.

[0018] Optionally, the thickness of the adhesive coating is 0.5 - 2 μm.

[0019] By adopting the above technical solution, the thickness of the single-sided adhesive coating is small, but it can achieve the bonding ability of a conventional hot-pressed composite separator. Moreover, the smaller thickness of the adhesive coating can shorten the migration path of ions in the separator, reduce the internal resistance of the battery, improve the charge and discharge efficiency. At the same time, the thinner adhesive coating has better electrolyte wettability and liquid retention, which can improve the cycle stability and safety of the battery.

[0020] Optionally, the adhesive is selected from at least one of carboxymethyl cellulose, polydopamine, styrene-butadiene rubber, and hydroxyethyl cellulose.

[0021] Optionally, the thickening agent is selected from at least one of nanoaluminum silicate, nanoaluminum magnesium silicate, porous silica sol, sodium carboxymethyl cellulose, methyl hydroxyethyl cellulose, polyvinyl alcohol, polyethylene oxide, and polyurethane.

[0022] In a second aspect, the present application provides a method for preparing a room-temperature bonding type coated separator, adopting the following technical solution: A method for preparing a room-temperature bonding type coated separator includes the following steps: Vacuum mix the shell material particles, core material particles and cross-linking agent to obtain a binder; Mix the binder with a thickening agent, isopropyl alcohol, an adhesive, a wetting agent and water, and stir evenly to obtain a bonding coating; Coat the bonding coating on at least one side of the base film and dry it to form a room-temperature bonding type coated separator.

[0023] By adopting the above technical solution, the shell material particles and core material particles form a core-shell structure through the action of the cross-linking agent, and a bonding coating is obtained by mixing with a thickening agent, etc. The bonding coating is coated on the base film by means of roll coating, spraying or dot coating, and a room-temperature bonding type separator can be obtained after drying. This separator has strong bonding force and can generate bonding force with the electrode sheet without hot pressing (room-temperature pressing), solving the problem of uneven heat transfer inside and outside the core of the hot pressing process, reducing the risk of the separator generating minute deformation due to heat, and improving the consistency of the battery core.

[0024] In summary, the present application has the following beneficial effects: Since the present application uses core material particles with a low glass transition temperature and large particle size, core material particles with a high glass transition temperature and small particle size react with the cross-linking agent to form binder particles with a core-shell structure. The shell material particles are smaller and surround the core material particles. When the binder particles are pressed, the core material particles are extruded from the gaps between the shell material particles and come into contact with the electrode sheet, thereby forming room-temperature bonding. Therefore, after the coating of the present application is coated on the base film, room-temperature pressing can complete the bonding, reducing the shrinkage of the separator caused by hot pressing. Moreover, the separator does not have bonding property at room temperature without pressing, preventing the separator from sticking after winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the room-temperature bonding type coated separator prepared in Example 1 of the present application; Figure 2 It is a schematic structural diagram of the binder particles in Example 1 of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following embodiments further illustrate the present application in detail. Embodiment

[0027] Embodiment 1: A room-temperature bonding type coated separator, as Figure 1As shown, it includes a base film and adhesive coatings on both sides of the base film. The base film includes a polypropylene base film with a thickness of 9 μm and a ceramic coating with a thickness of 2 μm that are bonded to each other. The base film is selected from Shanghai Dinghao New Material Technology Co., Ltd., with the model number PSC1S0911. The thickness of the adhesive coating on one side is 1 μm, and the adhesive coating is formed by curing an adhesive paint. The adhesive paint contains the following raw materials in weight percentages: 30% binder, 0.67% thickener, 0.5% isopropanol, 5% adhesive, 0.1% wetting agent, and the balance is water. As Figure 2 As shown, the binder is binder particles with a core-shell structure. The shell layer particles are centered around the core layer particles and surround the core layer particles in a circle. The binder particles contain core layer particles, shell layer particles, and crosslinking agent in a mass percentage of 40%:50%:10%. The glass transition temperature of the core layer particles is -44.3 °C. The core layer particles are polystyrene-modified polymethyl methacrylate, selected from Haodian Technology, with the model number HD6117B, and the D50 particle size is 0.93 μm. The glass transition temperature of the shell layer particles is 57.9 °C. The shell layer particles are polymethyl methacrylate, selected from Gaorui, with the model number GP71B, and the D50 particle size is 0.4 μm. The crosslinking agent is N-methylolacrylamide, the thickener is methyl hydroxyethyl cellulose, the adhesive is carboxymethyl cellulose, and the wetting agent is nanocellulose.

[0028] The preparation method of the above-mentioned room-temperature adhesive coating separator includes the following steps: Vacuum mix the shell layer particles, core layer particles, and crosslinking agent to obtain a binder; Mix the binder with the thickener, isopropanol, adhesive, wetting agent, and water, and stir evenly to obtain an adhesive paint; Roll coat the adhesive paint on one side of the polypropylene base film and one side of the ceramic coating respectively, and dry it at 80 °C for 45 seconds to form a room-temperature adhesive coating separator.

[0029] Figure 1 The structural schematic diagram of the prepared room-temperature adhesive coating separator is shown in. The shell layer particles surround the core layer particles to form binder particles with a core-shell structure.

[0030] Table 1 Raw material dosages of the adhesive paint in Examples 1-3 Examples 2-3: A room-temperature adhesive coating separator, which is different from Example 1 in that the raw material dosages of the adhesive paint are as shown in Table 1.

[0031] Example 4: A room-temperature bonding type coated separator, which is different from Example 1 in that the glass transition temperature of the core layer particles is -44.3 °C, the core layer particles are polystyrene-modified polymethyl methacrylate, selected from Haodian Technology, with the model number HD6117B, the D50 particle size is 0.93 μm, the glass transition temperature of the shell layer particles is 50 °C, the shell layer particles are polyacrylic acid, selected from Guangzhou Lanxi Chemical Industry, and the D50 particle size is 400 nm.

[0032] Example 5: A room-temperature bonding type coated separator, which is different from Example 1 in that the glass transition temperature of the core layer particles is -44.3 °C, the core layer particles are polystyrene-modified polymethyl methacrylate, selected from Haodian Technology, with the model number HD6117B, the D50 particle size is 0.93 μm, the glass transition temperature of the shell layer particles is 153 °C, the shell layer particles are polyacrylamide, selected from Hubei Yuancheng Saichuang Technology, and the molecular weight is 71.0779.

[0033] Example 6: A room-temperature bonding type coated separator, which is different from Example 1 in that the bonding particles contain core layer particles, shell layer particles and a crosslinking agent in a mass percentage of 10%:80%:10%.

[0034] Example 7: A room-temperature bonding type coated separator, which is different from Example 1 in that the bonding particles contain core layer particles, shell layer particles and a crosslinking agent in a mass percentage of 30%:60%:10%.

[0035] Example 8: A room-temperature bonding type coated separator, which is different from Example 1 in that on both sides of the base film composed of a 9-μm polypropylene base film and a 2-μm ceramic coating, a bonding coating is roll-coated respectively, and the bonding coating forms a bonding coating with a thickness of 0.5 μm on both the polypropylene base film side and the ceramic coating side.

[0036] Example 9: A room-temperature bonding type coated separator, which is different from Example 1 in that on both sides of the base film composed of a 9-μm polypropylene base film and a 2-μm ceramic coating, a bonding coating is roll-coated respectively, and the bonding coating forms a bonding coating with a thickness of 1.5 μm on both the polypropylene base film side and the ceramic coating side.

[0037] Example 10: A room-temperature bonding type coated separator, which is different from Example 1 in that on both sides of the base film composed of a 9-μm polypropylene base film and a 2-μm ceramic coating, a bonding coating is roll-coated respectively, and the bonding coating forms a bonding coating with a thickness of 2 μm on both the polypropylene base film side and the ceramic coating side.

[0038] Comparative Example Comparative Example 1: A room-temperature adhesive-coated separator, which is different from Example 1 in that the binder particles include core layer particles, shell layer particles, and cross-linking agent with a mass percentage of 50%:40%:10%.

[0039] Comparative Example 2: A adhesive-coated separator, which is different from Example 1 in that the glass transition temperature of the core layer particles is 90 °C, and the core layer particles are polyacrylonitrile, selected from Taicang Keldar Plastics.

[0040] Comparative Example 3: A commercially available lithium battery protective separator, a heat-resistant separator of model PSM1D0913 selected from Shanghai Dinghao New Materials Technology Co., Ltd., the base film includes a polypropylene base film with a thickness of 9 μm and a ceramic coating with a thickness of 2 μm that are bonded to each other, and adhesive-coated layers are located on both sides of the base film, and the thickness of one side is 1 μm.

[0041] Comparative Example 4: A room-temperature adhesive-coated separator, which is different from Example 1 in that core layer particles with a glass transition temperature of -44.3 °C and a D50 particle size of 0.93 μm are used to equally replace the shell layer particles. The core layer particles are polystyrene-modified polymethyl methacrylate, selected from Good Electric Technology, model HD6117B, that is, the same material is used as the core layer particles and the shell layer particles respectively.

[0042] Comparative Example 5: A room-temperature adhesive-coated separator, which is different from Example 1 in that, as shown in Table 1, the thickener dosage is 0.67% of the binder, the adhesive dosage is 5% of the binder, the wetting agent accounts for 0.1% of the binder, and the isopropanol dosage is 0.6% of the binder dosage.

[0043] Comparative Examples 6 - 9: A room-temperature adhesive-coated separator, which is different from Example 1 in that, as shown in Table 2, the binder contains binder particles with a core-shell structure and PVDF. PVDF is selected from Kayin Chemical Industry, brand name Arkema PVDF KYNAR761. The dosage percentages of the core-shell structure binder particles and PVDF in Example 6 are 80%:20%, the dosage percentages of the core-shell structure binder particles and PVDF in Example 7 are 60%:40%, the dosage percentages of the core-shell structure binder particles and PVDF in Example 8 are 40%:60%, and the dosage percentages of the core-shell structure binder particles and PVDF in Example 9 are 20%:80%. And in Examples 6 - 9, the thickener dosage is 0.67% of the total amount of the binder and PVDF, the adhesive dosage is 5% of the total amount of the binder and PVDF, the wetting agent accounts for 0.1% of the total amount of the binder and PVDF, and the isopropanol dosage is 0.6% of the total amount of the binder and PVDF.

[0044] Table 2 Raw material dosages of the adhesive coatings in Comparative Examples 5 - 10 Comparative Example 10: A coated separator, which is different from Example 1 in that PVDF is used to equally replace the binder particles with a core-shell structure as the binder. PVDF is selected from Kayin Chemical Industry, and the grade is Arkema PVDF KYNAR 761. The raw material dosage of the binder coating is shown in Table 2. The dosage of the thickener is 0.67% of the PVDF dosage, the dosage of the adhesive is 5% of the PVDF dosage, the dosage of the wetting agent is 0.1% of the PVDF dosage, and the dosage of isopropanol is 0.6% of the PVDF dosage.

[0045] Performance Detection Test Prepare the separators according to the methods in the examples and comparative examples, and conduct performance detection with reference to the following methods. Record the detection results in Table 3.

[0046] 1. Peel force with the electrode sheet: Bond with the negative electrode sheet under a pressure of 3 MPa for 90 s. After pressing, cut it into test samples with a size of 25×200 mm. Use a peel force tester with a stretching speed of 50 mm / min to test the peel force between the electrode sheet and the separator at different temperatures (25°C, 45°C, and 80°C). Test 5 specimens in each group, and take the average value of the test results; and at 25°C, bond with the negative electrode sheet under pressures of 1 MPa, 2 MPa, 3 MPa, 4 MPa, and 5 MPa for 90 s. After pressing, cut it into test samples with a size of 25×200 mm. Use a peel force tester with a stretching speed of 50 mm / min to test the peel force between the electrode sheet and the separator under different pressures. Test 5 specimens in each group, and take the average value of the test results; 2. Absorption rate of the electrolyte: Immerse the separator to be tested in the electrolyte for 1 h, and calculate the absorption rate of the electrolyte with the following formula: Electrolyte absorption rate = (W2 - W1) / W1×100%, where W1 and W2 represent the mass of the separator before and after impregnating the electrolyte, respectively.

[0047] 3. Permeability value: Detect according to the standard in GB / T 36363-2018 "Polyolefin Separators for Lithium-Ion Batteries". The test environment is 25°C±2°C, the relative humidity is 45%±5%, the pressure is a constant 1.21 kPa, and test the time required for 100 ml of air to pass through the separator with an area of 6.45 cm 2 of the separator.

[0048] 4. Permeability value increment: Detect the permeability value increment of each group of separators compared with the base film (9-μm polypropylene base film + 2-μm ceramic coating, the base film is selected from Shanghai Dinghao New Materials Technology Co., Ltd., model PSC1S0911). The calculation method is: (Permeability value of the test group - Permeability value of the base film) / Permeability value of the base film×100%.

[0049] Table 3 Performance Detection Results of Room Temperature Bonding Type Coated Separators Combining the data in Table 3 and the raw material selection and dosages in Examples 1-3, it can be seen that by using core layer particles with a low Tg temperature and large particle size, and shell layer particles with a high Tg temperature and small particle size, and mixing them with a cross-linking agent, binder particles with a core-shell structure can be formed. When compounding with the electrode sheet at room temperature, a strong adhesive force can be obtained, which is similar to the adhesive force with a conventional hot-pressed separator. Firm adhesion can be achieved without high-temperature hot pressing, reducing the risk of shrinkage of the separator under heat and pressure conditions. At the same time, it has a large electrolyte absorption rate, strong electrolyte wettability, and a small air permeability value.

[0050] Compared with Example 1, polyacrylic acid was used as the shell layer particles in Example 4, and compared with Example 1, polyacrylamide was used as the shell layer particles in Example 5. The glass transition temperature of the shell layer particles in Examples 4 and 5 changed. It can be seen that the bonding performance of the room-temperature bonding type coated separator prepared in Examples 4 and 5 decreased slightly compared with Example 1, but still had a good room-temperature bonding effect.

[0051] Compared with Example 1, different weight percentages of core layer particles and shell layer particles were used in Examples 6 and 7. It can be seen that the core layer particles decreased and the dosage of shell layer particles increased in Examples 6 and 7, resulting in a decrease in the room-temperature bonding ability of the separators prepared in Examples 6 and 7.

[0052] Compared with Example 1, coatings with different thicknesses were formed on both sides of the polyethylene separator in Examples 8, 9, and 10. It can be seen that the thicker the coating, the greater the peel force between the separator and the electrode sheet.

[0053] In Comparative Example 1, the dosage ratio of the shell layer particles and the core layer particles was changed. Compared with Example 1, the peel force between the separator and the electrode sheet decreased, and the other performance changes were not obvious; in Comparative Example 2, the glass transition temperature of the core layer particles was increased, and it can be seen that the peel force of the separator on the electrode sheet weakened.

[0054] In Comparative Example 3, a commercially available hot-pressed composite separator was used, which had no adhesive force at 25°C and 45°C and only had adhesive force at 80°C. It can be seen that the room-temperature composite separator in this application can achieve the peel force of the hot-pressed composite separator without hot-pressing composite, and reduces the risk of hot-press shrinkage of the separator and the probability of battery short circuit.

[0055] In Comparative Example 4, polystyrene-modified polymethyl methacrylate with the same glass transition temperature and the same particle size was used as the core layer particles and the shell layer particles. It can be seen that the prepared coated separator had good adhesive force, but the separator adhesion phenomenon occurred after winding.

[0056] In Comparative Example 5, the amounts of raw materials such as thickeners and wetting agents were changed, and it can be seen that it has good room-temperature bonding ability. Comparing Comparative Examples 6-9 with Example 1, PVDF was added to the binder, and it can be seen that as the amount of PVDF increases, the bonding performance increases. It can be seen that this binder composite coating has the effect of increasing the bonding force at room temperature. In Comparative Example 10, only PVDF was used as the binder, and it does not have room-temperature bonding ability.

[0057] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A room-temperature bonding type coating diaphragm, characterized in that, It includes a base film and an adhesive coating located on at least one side of the base film. The adhesive coating is formed by curing an adhesive paint, and the adhesive paint includes raw materials in the following weight percentages: 4-45% of binder, 0.6-0.7% of thickener, 0.4-0.6% of isopropyl alcohol, 4.5-5.5% of adhesive, 0.1-0.12% of wetting agent, and the balance is water; The binder is binder particles with a core-shell structure. The binder particles with a core-shell structure contain core layer particles, shell layer particles and crosslinking agent in a mass percentage of 10-40%:50-80%:10%; The glass transition temperature of the core layer particles is -(30 to 50) °C, and the glass transition temperature of the shell layer particles is ≥50 °C; The D50 particle size of the core layer particles is 0.8-10 μm, and the D50 particle size of the shell layer particles is 200-400 nm.

2. The room-temperature bonding type coating diaphragm according to claim 1, wherein: The binder particles with a core-shell structure contain core layer particles, shell layer particles and crosslinking agent in a mass percentage of 40%:50%:10%; The glass transition temperature of the core layer particles is -44.3 °C, and the glass transition temperature of the shell layer particles is 57.9 °C.

3. The room-temperature bonding type coating diaphragm according to claim 1, wherein: The D50 particle size of the core layer particles is 0.93 μm, and the D50 particle size of the shell layer particles is 200 nm.

4. The room-temperature bonding type coating diaphragm according to claim 1, wherein: The core layer particles are selected from at least one of modified polystyrene, modified polyacrylic acid, modified polyacrylonitrile, modified acrylamide, modified PVDF, etc.

5. The ambient-temperature adhesive coating separator according to claim 1, wherein: The shell layer particles are selected from at least one of polystyrene, polyacrylic acid, polyacrylonitrile, acrylamide, etc.

6. The ambient-temperature bonding type coating diaphragm according to claim 1, wherein: The crosslinking agent is selected from at least one of diacetone acrylamide, acetylacetoxyethyl methacrylate, N-methylol acrylamide, N-hydroxyethyl acrylamide, divinylbenzene, diallyl phthalate and trimethylolpropane triacrylate.

7. The room-temperature bonding type coating diaphragm according to claim 1, wherein: The thickness of the adhesive coating is 0.5-2 μm.

8. The room-temperature bonding type coated separator according to claim 1, characterized in that: The adhesive is selected from at least one of carboxymethyl cellulose, polydopamine, styrene-butadiene rubber and hydroxyethyl cellulose.

9. The room-temperature bonding type coated separator according to claim 1, wherein: The thickener is selected from at least one of nanoaluminum silicate, nanoaluminum magnesium silicate, porous silica sol, sodium carboxymethyl cellulose, methyl hydroxyethyl cellulose, polyvinyl alcohol, polyethylene oxide and polyurethane.

10. The preparation method of the room-temperature bonding type coated separator according to any one of claims 1-9, characterized in that: It includes the following steps: Vacuum mix the shell layer particles, core layer particles and crosslinking agent to obtain a binder; Mix the binder with the thickener, isopropyl alcohol, adhesive, wetting agent and water, and stir evenly to obtain an adhesive paint; Coat the adhesive paint on at least one side of the base film and dry it to form a room-temperature adhesive type coating separator.

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