Battery separator and manufacturing method therefor

Abstract

A battery separator, characterized in comprising: at least one base membrane; at least one inorganic layer positioned on the base membrane; and a plurality of polymer particles, the plurality of polymer particles being positioned on the inorganic layer, and the density of the polymer particles being less than the density of the inorganic layer. The prepared barium titanate and polymer particles having a multilayer structure are blended, the base membrane is coated with the blended slurry, the base membrane is dried in an oven. During drying, a difference in density is present between the barium titanate and the polymer particles, causing the barium titanate having a larger density to sink and the polymer particles to rise, and consequently the prepared battery separator has excellent heat resistance properties while having high adhesion.

Description

Battery separator and manufacturing method thereof Technical Field

[0001] The present invention relates to the field of lithium-ion battery separators, and in particular to a battery separator and a method for manufacturing the same. Background Art

[0002] The overuse of fossil fuels has led to serious environmental pollution. To address these issues, replacing fossil fuels with new energy materials has become increasingly important. Lithium-ion batteries, with their high energy density, safety, stability, and long cycle life, are widely used in consumer electronics, power products, and energy storage products.

[0003] Battery separators are important components in lithium battery cells. Currently, battery separators with microporous structures are usually made of polyolefin materials through extrusion, extraction, and stretching. In order to improve the heat resistance of the separator, a polyolefin base film is usually coated with an inorganic material with high heat resistance (such as ceramics, cellulose, aramid, etc.). However, inorganic particles have poor dispersibility, are easy to fall off, and have serious powder loss. They need to be used in combination with other components, which greatly increases the production cost. In addition, in order to meet the current battery preparation process requirements, it is necessary to ensure strong adhesion between the separator and the electrode to avoid misalignment of the tabs. The current solution for producing separators with high heat resistance and high adhesion is usually to coat an adhesive layer (PVDF) on the inorganic particle powder, but the softening point of PVDF is relatively high. When the hot pressing temperature is low, it is not easy to trigger the softening point of PVDF, resulting in no obvious adhesion between the separator and the positive and negative electrode sheets.

[0004] The battery separator proposed in the present invention can effectively solve the problems of poor heat resistance of existing battery separators, narrow hot pressing process window between separators and pole pieces, the need for secondary coating to prepare separators with high heat resistance and high adhesion, serious energy consumption, complex coating material formula, poor slurry stability resulting in large fluctuations in coating physical properties during the coating process, and has better performance than existing separators. Summary of the Invention

[0005] The object of the present invention is to provide a battery separator, characterized in that it includes: at least one base film; at least one inorganic layer located on the base film; a plurality of polymer particles, the plurality of polymer particles are located on the inorganic layer, and the density of the polymer particles is less than the density of the inorganic layer.

[0006] Preferably, the inorganic layer includes one or more of barium titanate, aluminum oxide, silicon dioxide, and titanium dioxide.

[0007] Preferably, the polymer particles include one or more of a polyacrylonitrile layer, a polystyrene layer, a polyvinylidene fluoride layer, a polymethyl methacrylate layer, and a polyacrylamide layer.

[0008] Preferably, the polymer particles have a vegetable oil layer on the outside.

[0009] Preferably, the vegetable oil layer comprises one or more of sunflower oil, Chinese tallow tree oil, olive oil, rubber seed oil, castor oil, tung oil, and palm oil.

[0010] Preferably, the polymer particles further include a plurality of cellulose nanofibrils, the plurality of cellulose nanofibrils are located outside the vegetable oil layer, and a portion of the plurality of cellulose nanofibrils is connected to the inorganic layer.

[0011] Preferably, the cellulose nanofibrils include one or more of absorbent cotton, paper pulp, wood pulp, and hemp.

[0012] Another object of the present invention is to provide a method for manufacturing a battery separator, which is characterized by comprising: mixing vegetable oil, N-methylethanolamine, and a catalyst, and sealing and heating to obtain a vegetable oil-based precursor; mixing the vegetable oil-based precursor and anhydride, and sealing and heating to obtain a vegetable oil-based acrylate monomer; mixing the vegetable oil-based acrylate monomer, perbenzoic acid, and sodium carbonate, and sealing and stirring at room temperature to obtain a vegetable oil-based epoxy monomer; uniformly mixing the vegetable oil-based acrylate epoxy monomer, styrene monomer, methyl methacrylate monomer, vinylidene fluoride monomer, and acrylonitrile monomer, and then adding the mixture dropwise to a cellulose nanofibril suspension, mixing and stirring to obtain an oil-water mixture, and treating the oil-water mixture with an ultrasonic crusher to obtain a Pickering emulsion; adding the Pickering emulsion dropwise to a mixed solvent of ethanol and water, adding a water-soluble initiator, cooling the mixture to room temperature after the reaction is completed, and filtering with a filter to obtain a polymer composite emulsion; mixing the polymer composite emulsion with an inorganic substance to obtain a coating slurry; coating the coating slurry on a base film, and drying to obtain a battery separator.

[0013] Preferably, the cellulose nanofibril suspension comprises one or more of absorbent cotton, paper pulp, wood pulp, and hemp.

[0014] Preferably, the inorganic substance includes one or more of barium titanate, aluminum oxide, silicon dioxide, and titanium dioxide.

[0015] Preferably, the heating temperature after mixing the vegetable oil, the N-methylethanolamine and the catalyst is 50 to 80°C, and the reaction time is 8 hours; the heating temperature after mixing the vegetable oil-based precursor and the acid anhydride is 60 to 80°C, and the reaction time is 8 to 12 hours; the stirring time of the vegetable oil-based acrylate monomer, the perbenzoic acid and the sodium carbonate is 12 hours.

[0016] Preferably, the ultrasonic crusher has a processing power of 600 to 800 watts and a processing time of 10 to 15 minutes. The Pickering emulsion is added dropwise to the mixed solvent and then the water-soluble initiator is added and polymerized at 60 to 80° C. for 2 to 4 hours.

[0017] Preferably, the oil-water ratio of the oil-water mixture is 1 to 4 to 8.

[0018] Preferably, the water-soluble initiator includes one or more of ammonium persulfate, potassium persulfate, and peroxide.

[0019] Preferably, after the coating slurry is coated on the base film, it is dried at 60 to 90° C. for 0.5 to 3 minutes.

[0020] This disclosure uses plant oils as raw materials to synthesize plant oil-based acrylate monomers. Methacrylate monomers, vinylidene fluoride monomers, acrylonitrile monomers, acrylamide monomers, and styrene monomers are added in certain proportions. Cellulose nanofibrils are used as stabilizers, a mixture of ethanol and water is used as a dispersant, and azobisisobutyronitrile is used as an initiator for dispersion polymerization. This preparation method is more environmentally friendly than existing methods. The prepared multilayered polymer microparticles are then blended with barium titanate. The blended slurry is directly coated on a base film and then dried in an oven. During the drying process, the density difference between the barium titanate and the polymer microparticles causes the denser barium titanate to sink while the polymer microparticles float. This results in a battery separator with excellent heat resistance and high adhesion. Furthermore, the production process requires only a single coating, significantly reducing energy consumption and costs compared to the currently commonly used two-coating method. At the same time, the battery separator proposed by the present invention can be adapted to the hot pressing processes of different battery manufacturers, and has adhesion to the electrode at a hot pressing temperature between 25 and 150°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic diagram of a battery separator according to an embodiment of the present invention.

[0022] FIG2 is a schematic diagram of polymer particles according to an embodiment of the present invention.

[0023] FIG3 is a flow chart of a method for manufacturing a battery separator according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0025] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0026] Please refer to Figure 1, which is a schematic diagram of a battery separator in one embodiment of the present invention. The battery separator 100 includes at least one base film 1, at least one inorganic layer 2, and a plurality of polymer particles 3. In one embodiment of the present invention, the polymer particles 3 are spherical. The inorganic layer 2 is located between the base film 1 and the plurality of polymer particles 3. The polymer particles 3 have a multilayer structure, and the density of the polymer particles 3 is less than the density of the inorganic layer 2. Preferably, the base film 1 can be made of polypropylene, and the inorganic layer 2 can include one or more of barium titanate, aluminum oxide, silicon dioxide, and titanium dioxide.

[0027] Please refer to Figure 2, which is a schematic diagram of polymer particles according to one embodiment of the present invention. Polymer particles 3 are high molecular weight polymers. Polymer particles 3 may include one or more of a polyacrylonitrile layer 31, a polystyrene layer 32, a polyvinylidene fluoride layer 33, a polymethyl methacrylate layer 34, and a polyacrylamide layer 35. In one embodiment of the present invention, polymer particles 3 include, from the inside to the outside, a polyacrylonitrile layer 31, a polystyrene layer 32, a polyvinylidene fluoride layer 33, a polymethyl methacrylate layer 34, a polyacrylamide layer 35, a plant oil layer 36, and a plurality of cellulose nanofibrils 37. Preferably, the plant oil layer 36 may include one or more of sunflower oil, Chinese tallow tree oil, olive oil, rubber seed oil, castor oil, tung oil, and palm oil, and the cellulose nanofibrils may include one or more of absorbent cotton, paper pulp, wood pulp, and hemp.

[0028] Please refer to Figure 3, which is a flow chart of a method for manufacturing a battery separator according to an embodiment of the present invention. The detailed description of the manufacturing method is as follows.

[0029] In step S1, a vegetable oil-based acrylate epoxy monomer is first prepared. 8 to 20 parts of vegetable oil, 1 to 4 parts of N-methylethanolamine, and 0.1 to 1 part of a catalyst are mixed, sealed and heated to 50 to 80°C and reacted for 8 hours, after which the unreacted matter and the catalyst are removed to obtain a vegetable oil-based precursor. 8 to 20 parts of a vegetable oil-based precursor and 2 to 15 parts of anhydride are mixed, sealed and heated to 60 to 80°C and reacted for 8 to 12 hours, after which the unreacted matter is removed to obtain a vegetable oil-based acrylate monomer. 8 to 20 parts of a vegetable oil-based acrylate monomer, 2 to 5 parts of perbenzoic acid, and 5 to 10 parts of sodium carbonate are mixed, sealed and stirred at room temperature for 12 hours, after which the unreacted matter is removed to obtain a vegetable oil-based acrylate epoxy monomer.

[0030] In step S2, a polymer composite emulsion and a coating slurry are prepared. 8 to 20 parts of vegetable oil-based acrylate epoxy monomer, 1 to 8 parts of styrene monomer, 1 to 3 parts of methyl methacrylate, 2 to 5 parts of vinylidene fluoride monomer, and 3 to 5 parts of acrylonitrile monomer are mixed and then added dropwise to 40 to 400 parts of cellulose nanofibril suspension. After stirring evenly, an oil-water mixture is obtained, which is then treated with an ultrasonic crusher with a power of 600 to 800 watts for 10 to 15 minutes to obtain a Pickering emulsion. 60 to 80 parts of the Pickering emulsion are added dropwise to a mixed solvent of ethanol and water, and 0.2 to 0.4 parts of a water-soluble initiator are added. Preferably, the water-soluble initiator can include one or more of ammonium persulfate, potassium persulfate, and peroxide. The mixed solution is then placed in a constant temperature device and polymerized at 60 to 80°C for 2 to 4 hours. After the reaction is complete, the mixture is cooled to room temperature and filtered through a 100-300 mesh nylon filter to obtain a polymer composite emulsion. Preferably, the oil-water ratio of the oil-water mixture is 1:4 to 8. Finally, 10-30 parts of the polymer composite emulsion are blended with 70-90 parts of barium titanate to obtain a coating slurry.

[0031] In another embodiment of the present invention, the formula ratio can be 0.1 to 2 parts cellulose nanofibrils, 3 to 7 parts vegetable oil polymer, 1 to 3 parts polystyrene, 3 to 6 parts polymethyl methacrylate, 1 to 5 parts polyvinylidene fluoride, 1 to 3 parts polyacrylonitrile, 1 to 4 parts polyacrylamide, and 70 to 89.9 parts barium titanate, for a total of 100 parts. In another embodiment of the present invention, the solid content of the cellulose nanofibrils is 0.1 wt% to 1 wt%.

[0032] In step S3, a battery separator is prepared by evenly coating 1 to 3 parts of the coating slurry on the base film 1 using a roller coating method and drying it in a forced air oven at 60 to 90°C for 0.5 to 3 minutes. After drying, a battery separator with both heat resistance and adhesiveness is obtained.

[0033] The following examples illustrate the method for preparing the battery separator disclosed in this disclosure.

[0034] Example 1:

[0035] The preparation method of vegetable oil-based acrylate epoxy monomer specifically comprises the following steps:

[0036] (1) According to the mass fraction, 50 parts of palm oil were taken and purged with nitrogen at 100°C for 30 minutes. After the palm oil was heated to 65°C, 8 parts of amino alcohol and 1 part of sodium methoxide solution (5 mol / L) were added. After the reaction was sealed at 65°C for 8 hours, the mixture was poured into 50 parts of dichloromethane (DCM) to dissolve, and then washed with saturated sodium chloride and dried with anhydrous magnesium sulfate to obtain a plant oil-based precursor.

[0037] (2) 50 parts of a vegetable oil-based precursor, 15 parts of an acid anhydride, and 0.4 parts of 4-dimethylaminopyridine were mixed, sealed and heated to 65°C for 8 hours, and then poured into 50 parts of dichloromethane for dissolution. The mixture was washed with saturated sodium bicarbonate and saturated sodium chloride, respectively, and then dried with anhydrous magnesium sulfate and passed through an alkaline alumina column to obtain a vegetable oil-based acrylate monomer.

[0038] (3) 50 parts of vegetable oil-based monomer, 10 parts of sodium carbonate, and 6 parts of hydrogen peroxide were added dropwise to 50 parts of dichloromethane to dissolve, and then stirred at room temperature for 8 hours, washed with saturated sodium thiosulfate, saturated sodium bicarbonate, and saturated sodium chloride solutions, dried with anhydrous magnesium sulfate, and then passed through an alkaline alumina column to obtain a vegetable oil-based acrylate epoxy monomer.

[0039] Example 2:

[0040] The preparation method of the battery separator specifically comprises the following steps:

[0041] (1) 5 parts by weight of the vegetable oil-based acrylate epoxy monomer prepared in Example 1, 2 parts of styrene monomer, 4 parts of methyl methacrylate, 3 parts of vinylidene fluoride, 2 parts of acrylonitrile, and 4 parts of acrylamide monomer were mixed and added dropwise to 80 parts of a 0.2 wt% cellulose nanofibril suspension. After thorough mixing, the mixture was ultrasonically disrupted at 600 watts for 10 minutes to obtain Pickering Emulsion 1. The stability, particle size, and viscosity parameters of Pickering Emulsion 1 are shown in Table 1.

[0042] (2) 50 parts of Pickering emulsion 1 were placed in a thermostat at 65°C, deoxygenated with nitrogen for 30 minutes, and then 0.2 parts of a water-soluble initiator, potassium persulfate, were added and reacted for 3 hours. The temperature was then raised to 80°C, reacted for 30 minutes, and then cooled to room temperature. The mixture was then filtered through a 100-mesh nylon filter to obtain a polymer composite emulsion.

[0043] (3) 10 parts of the polymer composite emulsion was mixed with 90 parts of a barium titanate solution (solid content 20 wt%) and mechanically stirred for 2 hours to prepare a coating slurry. The slurry was then evenly coated on a polypropylene base film using a roller coater and dried in an oven at 60°C for 1 minute to obtain a battery separator.

[0044] Comparative Example 1:

[0045] The preparation method of the battery separator specifically comprises the following steps:

[0046] (1) 5 parts by weight of the vegetable oil-based acrylate epoxy monomer prepared in Example 1, 2 parts of styrene monomer, 4 parts of methyl methacrylate, 3 parts of vinylidene fluoride, 2 parts of acrylonitrile, and 4 parts of acrylamide monomer were mixed and added dropwise to 80 parts of a 0.5 wt% cellulose nanofibril suspension. After thorough mixing, the mixture was ultrasonically disrupted at 600 watts for 10 minutes to obtain Pickering Emulsion 2. The stability, particle size, and viscosity parameters of Pickering Emulsion 2 are shown in Table 1.

[0047] (2) 50 parts of Pickering emulsion 2 were placed in a thermostat at 65°C, deoxygenated with nitrogen for 30 minutes, and then 0.2 parts of a water-soluble initiator, potassium persulfate, were added to react for 3 hours. The temperature was then raised to 80°C, reacted for 30 minutes, and then cooled to room temperature. The mixture was then filtered through a 100-mesh nylon filter to obtain a polymer composite emulsion.

[0048] (3) 10 parts of the polymer composite emulsion was mixed with 90 parts of a barium titanate solution (solid content 20 wt%) and mechanically stirred for 2 hours to prepare a coating slurry. The slurry was then evenly coated on a polypropylene base film using a roller coater and dried in an oven at 60°C for 1 minute to obtain a battery separator.

[0049] Comparative Example 2:

[0050] The preparation method of the battery separator specifically comprises the following steps:

[0051] (1) 5 parts by weight of the vegetable oil-based acrylate epoxy monomer prepared in Example 1, 2 parts of styrene monomer, 4 parts of methyl methacrylate, 3 parts of vinylidene fluoride, 2 parts of acrylonitrile, and 4 parts of acrylamide monomer were mixed and added dropwise to 160 parts of a 0.2 wt% cellulose nanofibril suspension. After thorough mixing, the mixture was ultrasonically disrupted at 600 watts for 10 minutes to obtain Pickering Emulsion 3. The stability, particle size, and viscosity parameters of Pickering Emulsion 3 are shown in Table 1.

[0052] (2) 50 parts of Pickering emulsion 3 were placed in a thermostat at 65°C, deoxygenated with nitrogen for 30 minutes, and then 0.2 parts of a water-soluble initiator, potassium persulfate, were added and reacted for 3 hours. The temperature was then raised to 80°C, reacted for 30 minutes, and then cooled to room temperature. The mixture was filtered through a 100-mesh nylon filter to obtain a polymer composite emulsion.

[0053] (3) 10 parts of the polymer composite emulsion was mixed with 90 parts of a barium titanate solution (solid content 20 wt%) and mechanically stirred for 2 hours to prepare a coating slurry. The slurry was then evenly coated on a polypropylene base film using a roller coater and dried in an oven at 60°C for 1 minute to obtain a battery separator.

[0054] Comparative Example 3:

[0055] The preparation method of the battery separator specifically comprises the following steps:

[0056] (1) 5 parts by mass of the vegetable oil-based acrylate epoxy monomer prepared in Example 1, 2 parts by mass of styrene monomer, 4 parts by mass of methyl methacrylate, 3 parts by mass of vinylidene fluoride, 2 parts by mass of acrylonitrile, and 4 parts by mass of acrylamide monomer were added dropwise to 80 parts by mass of a 0.2 wt% cellulose nanofibril suspension. The mixture was thoroughly mixed and then treated with a 600-watt ultrasonic disruptor for 10 minutes to obtain a Pickering emulsion 1.

[0057] (2) 50 parts of Pickering emulsion 1 were placed in a thermostat at 65°C, deoxygenated with nitrogen for 30 minutes, and then 0.2 parts of a water-soluble initiator, potassium persulfate, were added to react for 3 hours. The temperature was then raised to 80°C, reacted for 30 minutes, and then cooled to room temperature. The mixture was filtered through a 100-mesh nylon filter to obtain a polymer composite emulsion.

[0058] (3) Take 10 parts of the polymer composite emulsion and evenly coat it on a polypropylene base film using a roller coater, and dry it in an oven at 60°C for 1 minute to obtain a battery separator.

[0059] Table 1

[0060] The characteristic parameters of the battery separators prepared in Example 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are shown in Table 2. As can be seen from Table 2, the battery separator prepared in Example 2 has the smallest thermal shrinkage and the largest positive electrode bonding strength.

[0061] Table 2

[0062] This disclosure uses plant oils as raw materials to synthesize plant oil-based acrylate monomers. Methacrylate monomers, vinylidene fluoride monomers, acrylonitrile monomers, acrylamide monomers, and styrene monomers are added in certain proportions. Cellulose nanofibrils are used as stabilizers, a mixture of ethanol and water is used as a dispersant, and azobisisobutyronitrile is used as an initiator for dispersion polymerization. This preparation method is more environmentally friendly than existing methods. The prepared multilayered polymer microparticles are then blended with barium titanate. The blended slurry is directly coated on a base film and then dried in an oven. During the drying process, the density difference between the barium titanate and the polymer microparticles causes the denser barium titanate to sink while the polymer microparticles float. This results in a battery separator with excellent heat resistance and high adhesion. Furthermore, the production process requires only a single coating, significantly reducing energy consumption and costs compared to the currently commonly used two-coating method. At the same time, the battery separator proposed by the present invention can be adapted to the hot pressing processes of different battery manufacturers, and has adhesion to the electrode at a hot pressing temperature between 25 and 150°C.

[0063] The above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The technical scope of the present invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A battery separator, characterized in that: include: at least one basement membrane; At least one inorganic layer, located on the base film; A plurality of polymer particles are disposed on the inorganic layer, and the density of the polymer particles is lower than that of the inorganic layer.

2. The battery separator according to claim 1, characterized in that: The inorganic layer includes one or more of barium titanate, aluminum oxide, silicon dioxide, and titanium dioxide.

3. The battery separator according to claim 2, characterized in that: The polymer particles include one or more of a polyacrylonitrile layer, a polystyrene layer, a polyvinylidene fluoride layer, a polymethyl methacrylate layer, and a polyacrylamide layer.

4. The battery separator according to claim 3, characterized in that: The outer side of the polymer particles is provided with a vegetable oil layer.

5. The battery separator according to claim 4, characterized in that: The vegetable oil layer includes one or more of sunflower seed oil, Chinese tallow tree oil, olive oil, rubber seed oil, castor oil, tung oil and palm oil.

6. The battery separator according to claim 4, characterized in that: The polymer particles further include a plurality of cellulose nanofibrils, the plurality of cellulose nanofibrils are located outside the vegetable oil layer, and a portion of the plurality of cellulose nanofibrils is connected to the inorganic layer.

7. The battery separator according to claim 6, characterized in that: The cellulose nanofibrils include one or more of absorbent cotton, paper pulp, wood pulp, and hemp.

8. A method for manufacturing a battery separator, characterized in that: include: The vegetable oil, N-methylethanolamine and a catalyst are mixed, sealed and heated to obtain a vegetable oil-based precursor; The plant oil-based precursor and the acid anhydride are mixed, sealed and heated to obtain a plant oil-based acrylate monomer; The vegetable oil-based acrylate monomer, perbenzoic acid and sodium carbonate are mixed, sealed and stirred at room temperature to obtain a vegetable oil-based epoxy monomer; The plant oil-based acrylate epoxy monomer, styrene monomer, methyl methacrylate monomer, vinylidene fluoride monomer, and acrylonitrile monomer are uniformly mixed and then added dropwise to the cellulose nanofibril suspension, and an oil-water mixture is obtained after mixing and stirring, and the oil-water mixture is treated with an ultrasonic crusher to obtain a Pickering emulsion; The Pickering emulsion is added dropwise to a mixed solvent of ethanol and water, a water-soluble initiator is added, the temperature is cooled to room temperature after the reaction is completed, and then filtered with a filter to obtain a polymer composite emulsion; Mixing the polymer composite emulsion with an inorganic substance to obtain a coating slurry; The coating slurry is coated on a base film and dried to obtain a battery separator.

9. The method for manufacturing a battery separator according to claim 8, characterized in that: The cellulose nanofibril suspension includes one or more of absorbent cotton, paper pulp, wood pulp and hemp.

10. The method for manufacturing a battery separator according to claim 8, characterized in that: The inorganic substance includes one or more of barium titanate, aluminum oxide, silicon dioxide and titanium dioxide.

11. The method for manufacturing a battery separator according to claim 8, characterized in that: The heating temperature after mixing the vegetable oil, the N-methylethanolamine and the catalyst is 50 to 80° C., and the reaction time is 8 hours. The heating temperature after mixing the vegetable oil-based precursor and the acid anhydride is 60 to 80° C., and the reaction time is 8 to 12 hours. The stirring time of mixing the vegetable oil-based acrylate monomer, the perbenzoic acid and the sodium carbonate is 12 hours.

12. The method for manufacturing a battery separator according to claim 11, characterized in that: The processing power of the ultrasonic crusher is 600 to 800 watts, and the processing time is 10 to 15 minutes. The Pickering emulsion is added dropwise to the mixed solvent and then the water-soluble initiator is added to polymerize at 60 to 80° C. for 2 to 4 hours.

13. The method for manufacturing a battery separator according to claim 8, characterized in that: The oil-water ratio of the oil-water mixture is 1:4 to 8.

14. The method for manufacturing a battery separator according to claim 8, characterized in that: The water-soluble initiator includes one or more of ammonium persulfate, potassium persulfate, and peroxide.

15. The method for manufacturing a battery separator according to claim 12, characterized in that: The coating slurry is coated on the base film and then dried at 60 to 90° C. for 0.5 to 3 minutes.

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