Boron carbon nitride based ion sieve coating diaphragm as well as preparation method and application thereof

Abstract

The invention relates to the technical field of diaphragms, and provides a boron carbon nitride-based ion sieve coating diaphragm as well as a preparation method and application thereof. The boron-carbon nitride-based ion sieve coating diaphragm comprises a base membrane and an ion sieve coating coated on the surface of the base membrane, the ion sieve coating comprises the following raw materials in parts by weight: 10-20 parts of boron-carbon nitride nanosheets, 65-80 parts of modified ceramic particles, 5-12 parts of a binder and 1-3 parts of a dispersant, and a modifier of the modified ceramic particles is amino silane. And the binder is a self-crosslinking acrylate copolymer containing amino groups. According to the technical scheme, the problem that the metal ion rejection rate of the diaphragm is insufficient in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of membrane technology, specifically to a boron nitride carbon-based ion sieve coated membrane, its preparation method, and its application. Background Technology

[0002] Currently, lithium manganese iron phosphate and high-temperature modified lithium iron phosphate have become the mainstream cathode materials for power batteries and energy storage batteries due to their cost advantages, high safety, and good cycle performance. However, during high-temperature (above 60°C) charge and discharge processes, the Mn² content in the cathode material... + Fe³ + When metal ions are easily dissolved, they can migrate through the traditional separator to the surface of the negative electrode, catalyzing the decomposition of the electrolyte and destroying the solid electrolyte interphase (SEI) membrane. This leads to rapid capacity decay and shortened cycle life, severely restricting the application expansion of high-temperature lithium iron phosphate batteries.

[0003] In existing technologies, coating membranes that address the problem of metal ion leaching mainly include ceramic-coated membranes and MOF-modified membranes. Ceramic-coated membranes can only improve the membrane's high-temperature resistance but cannot achieve selective retention of metal ions. Although MOF-modified membranes have a certain ion adsorption capacity, they suffer from drawbacks such as high cost, poor mechanical properties, and the ease with which MOF active sites are coated by binders, making it difficult to achieve an ion retention efficiency exceeding 90%.

[0004] Therefore, it is essential to develop a membrane with a high metal ion rejection rate. Summary of the Invention

[0005] This invention proposes a boron nitride carbon-based ion sieve coating diaphragm, its preparation method and application, which solves the problem of insufficient metal ion rejection rate of diaphragms in related technologies.

[0006] The technical solution of the present invention is as follows: The present invention proposes a boron nitride carbon-based ion sieve coating membrane, comprising a base membrane and an ion sieve coating coated on the surface of the base membrane. The ion sieve coating comprises the following raw materials in parts by weight: 10-20 parts of boron nitride carbon nanosheets, 65-80 parts of modified ceramic particles, 5-12 parts of binder, and 1-3 parts of dispersant. The modifier of the modified ceramic particles is an aminosilane, and the binder is an amino-containing self-crosslinking acrylate copolymer.

[0007] As a further technical solution, the aminosilane includes one or two of γ-aminopropyltriethoxysilane and γ-aminopropyltrimethoxysilane, preferably γ-aminopropyltriethoxysilane.

[0008] As a further technical solution, the preparation method of the modified ceramic particles includes the following steps: adding ceramic particles to anhydrous ethanol, stirring, adding aminosilane, mixing, filtering, and drying to obtain the modified ceramic particles.

[0009] As a further technical solution, the mass ratio of the anhydrous ethanol to the ceramic particles is 8:1 to 12:1, preferably 10:1.

[0010] As a further technical solution, the ceramic particles are alumina.

[0011] As a further technical solution, the mixing temperature is 60~70℃, preferably 65℃, and the mixing time is 2~3h, preferably 2.5h.

[0012] As a further technical solution, the degree of modification of the modified ceramic particles is 5wt%~10wt%, preferably 8wt%.

[0013] As a further technical solution, the amination rate of the adhesive is 5%~12%.

[0014] As a further technical solution, the adhesive has a solid content of 25% to 35%, a viscosity of 800 to 1500 mPa·s at room temperature, and a molecular weight of 30,000 to 80,000 g / mol.

[0015] As a further technical solution, the method for preparing the adhesive includes the following steps: A1. Mix MMA, BA, AM, and NMA, add an emulsifier aqueous solution and 4 / 5 of APS, and shear at 3000 r / min for 15 min to obtain a water pre-emulsion. A2. Add deionized water to the reactor and heat to 90-95℃. Adjust the pH of the system to 7.0-8.0 with ammonia. Add the pre-emulsion dropwise to the reactor at a rate of 1.0-1.5 mL / min for 1.5-2 hours. After the addition is complete, continue to keep the temperature at 90℃ for 2 hours. Add the remaining APS. After the temperature is maintained, quickly cool to room temperature (cooling rate ≥5℃ / min). Filter the cooled emulsion through a 200-mesh filter to obtain the binder.

[0016] As a further technical solution, the emulsifier aqueous solution is a sodium dodecylbenzenesulfonate aqueous solution with a concentration of 10 wt%.

[0017] In the boron nitride carbon-based ion sieve coating membrane of the present invention, the ammoniation rate of the binder is determined by the raw material ratio during the preparation process.

[0018] In this invention, the ammoniation rate of the binder is determined by acid-base titration. The purified copolymer is dissolved in an ethanol-water mixed solvent, and bromophenol blue is used as an indicator. The solution is titrated to the endpoint with a 0.05 mol / L hydrochloric acid standard solution, and the amino content, i.e., the ammoniation rate, is calculated.

[0019] As a further technical solution, the preparation method of the boron nitride nanosheets includes the following steps: mixing melamine with boric acid, heating to 800~1000℃, preferably 900℃, under an argon atmosphere, holding at the temperature and then cooling to obtain boron nitride material, placing the boron nitride material in water, sonicating and then centrifuging to obtain boron nitride nanosheets.

[0020] In the boron nitride carbon-based ion sieve coating membrane of this invention, the significant difference in electronegativity between B and N atoms in the BCN material (B: 2.04, N: 3.04) results in a strongly polar BN bond, creating a localized electric field on the surface of the BCN nanosheets. The dissolved metal ions (Mn...) 2+ Fe 3+ It carries a positive charge and will electrostatically adsorb onto the polar sites on the BCN surface, further enhancing the retention effect of harmful metal ions.

[0021] As a further technical solution, the molar ratio of melamine to boric acid is 1:1 to 1.5.

[0022] As a further technical solution, the power of the ultrasonic treatment is 300~500W, and the ultrasonic treatment time is 30~60min.

[0023] As a further technical solution, the heating rate is 5~10℃ / min, preferably 8℃ / min, and the holding time is 2~4h, preferably 3h.

[0024] As a further technical solution, the dispersant is a polycarboxylate dispersant, the viscosity of the dispersant is 50~150 mPa·s, the solid content is 30%~45%, and the pH is 7~10.

[0025] As a further technical solution, the particle size of the ceramic particles in the raw material of the modified ceramic particles is 0.3μm~0.5μm.

[0026] This invention also proposes a method for preparing a boron nitride carbon-based ion sieve coated membrane, which includes the following steps: S1. The dispersant is mixed with water, and after the first stirring and first dispersion, the boron nitride nanosheets are added; after the second stirring and second dispersion, the modified ceramic particles are added; after the third stirring and third dispersion, the binder is added; after the fourth stirring and fourth dispersion, a mixture is obtained. S2. The mixture is subjected to ultrasonic treatment to obtain a slurry; S3. The slurry is coated on at least one side of the base membrane and dried to obtain the boron nitride carbon-based ion sieve coated membrane.

[0027] As a further technical solution, the first stirring and the first dispersion are performed simultaneously, the first stirring rate is 30~40 r / min, the first dispersion rate is 1000~2000 r / min, and the time is 40~60 min.

[0028] As a further technical solution, the second stirring and the second dispersion are carried out simultaneously. The stirring rate of the second stirring is 30~40 r / min, the dispersion rate of the second dispersion is 1000~2000 r / min, and the time is 40~60 min.

[0029] As a further technical solution, the third stirring and the third dispersion are performed simultaneously, the third stirring rate is 30~40 r / min, the third dispersion rate is 1000~2000 r / min, and the time is 60~80 min.

[0030] As a further technical solution, the fourth stirring and the fourth dispersion are performed simultaneously. The stirring rate of the fourth stirring is 30~40 r / min, the dispersion rate of the fourth dispersion is 1000~2000 r / min, and the time is 40~60 min.

[0031] As a further technical solution, the power of the ultrasonic treatment is 400W, and the ultrasonic treatment time is 40~60min.

[0032] As a further technical solution, the coating speed is 60~100m / min, preferably 80m / min, and the thickness of the boron nitride carbon-based ion sieve coating is 0.6~2μm, preferably 1.2μm.

[0033] As a further technical solution, the drying temperature is 50~70℃, preferably 60℃, and the drying time is 1~3min, preferably 2min.

[0034] As a further technical solution, the base membrane includes one of polyethylene base membrane, polypropylene base membrane, and polyolefin composite porous membrane, preferably a polypropylene base membrane.

[0035] As a further technical solution, the thickness of the base film is 10 μm.

[0036] The present invention also proposes the application of the boron nitride carbon-based ion sieve coated separator prepared by the aforementioned method in batteries.

[0037] The working principle and beneficial effects of this invention are as follows: In this invention, the boron nitride carbon-based ion sieve coating membrane utilizes boron nitride carbon nanosheets in the coating to efficiently retain harmful metal ions and suppress side reactions. The addition of modified ceramic particles, specifically aminosilane as the modifier, not only enhances the coating's high-temperature stability but also allows its surface-modifying groups to form hydrogen bonds with the BCN nanosheets, inhibiting BCN aggregation. Furthermore, the amino groups in the amino-containing self-crosslinking acrylate copolymer assist in the adsorption of metal ions. These three elements synergistically achieve highly efficient ion retention and high Li- content. + The dual performance objectives of conduction. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] In the following examples and comparative examples: Dispersant: Polycarboxylate dispersant, model number 6227.

[0040] Example 1 The preparation method of boron carbon nitride nanosheets includes the following steps: melamine and boric acid are mixed, heated to 900℃ at a heating rate of 8℃ / min under an argon atmosphere, held at this temperature for 3 hours, and then cooled to obtain boron carbon nitride material. The boron carbon nitride material is placed in water, ultrasonically treated at 400W for 45 minutes, and then centrifuged to obtain boron carbon nitride nanosheets; the molar ratio of melamine to boric acid is 1:1. The preparation method of modified ceramic particles includes the following steps: adding alumina (particle size of 0.3 μm) to anhydrous ethanol, stirring, adding γ-aminopropyltriethoxysilane, mixing at 65℃ for 2.5 h, filtering, and drying to obtain modified ceramic particles with a modification degree of 8 wt%; the mass ratio of alumina to anhydrous ethanol is 1:10. The method for preparing the adhesive includes the following steps: A1. Mix MMA, BA, AM, and NMA, add sodium dodecylbenzenesulfonate aqueous solution (concentration of 10wt%) and 0.4 parts APS, and shear at 3000r / min for 15min to obtain a water preemulsion. A2. Add deionized water to the reactor and heat to 92℃. Adjust the pH of the system to 7.5 with ammonia. Add the pre-emulsion dropwise to the reactor at a rate of 1.2 mL / min over a period of 1.8 h. After the addition is complete, continue to heat at 90℃ for 2 h. Then add 0.1 parts of APS. After the heating is complete, quickly cool to room temperature (cooling rate of 5℃ / min). Filter the cooled emulsion through a 200-mesh filter to obtain the binder. The binder has an amination rate of 8%, and the raw material formula is as follows: 40 parts MMA, 10 parts BA, 4.5 parts AM, 2.5 parts NMA, 1.2 parts sodium dodecylbenzenesulfonate, 0.5 parts APS, and 100 parts deionized water; The ion sieve coating comprises the following raw materials in parts by weight: 10 parts boron nitride carbon nanosheets, 65 parts modified ceramic particles, 5 parts binder, and 1 part dispersant; A method for preparing a boron nitride carbon-based ion sieve coated membrane includes the following steps: S1. Mix the dispersant with water, stir at 35 r / min and disperse at 1500 r / min for 35 min, then add boron nitride carbon nanosheets; stir at 35 r / min and disperse at 1500 r / min for 35 min, then add modified ceramic particles; stir at 35 r / min and disperse at 1500 r / min for 70 min, then add the binder; stir at 35 r / min and disperse at 1500 r / min for 35 min to obtain a mixture; S2. The mixture is ultrasonically treated at 400W for 50 minutes to obtain a slurry; S3. The slurry is coated on one side of the base film at a coating rate of 80 m / min and a coating thickness of 1.2 μm. After drying at 60℃ for 2 min, a boron nitride carbon-based ion sieve coated membrane is obtained.

[0041] Example 2 Compared with Example 1, Example 2 differs in that the molar ratio of melamine to boric acid is 1:1.2, the alumina particle size is 0.4 μm, and the ion sieve coating comprises the following raw materials in parts by weight: 15 parts of boron nitride nanosheets, 70 parts of modified ceramic particles, 10 parts of binder, and 2 parts of dispersant. Example 3 Compared with Example 1, Example 3 differs in that the molar ratio of melamine to boric acid is 1:1.5, the alumina particle size is 0.5μm, and the ion sieve coating comprises the following raw materials in parts by weight: 20 parts of boron nitride nanosheets, 80 parts of modified ceramic particles, 12 parts of binder, and 3 parts of dispersant.

[0042] Example 4 The difference between Example 4 and Example 2 is that the degree of modification of the modified ceramic particles is 3wt%.

[0043] Example 5 The difference between Example 5 and Example 2 is that the degree of modification of the modified ceramic particles is 12 wt%.

[0044] Example 6 Compared with Example 2, Example 6 differs in that the amination rate of the adhesive is 3 wt%, and the adhesive formulation is 40 parts MMA, 10 parts BA, 1.7 parts AM, 2.5 parts NMA, 1.2 parts sodium dodecylbenzenesulfonate, 0.35 parts APS, and 100 parts deionized water.

[0045] Example 7 Compared with Example 2, Example 7 differs in that the amination rate of the adhesive is 15 wt%, and the adhesive formulation is 40 parts MMA, 10 parts BA, 8.8 parts AM, 2.5 parts NMA, 1.2 parts sodium dodecylbenzenesulfonate, 0.55 parts APS, and 100 parts deionized water.

[0046] Example 8 Compared with Example 2, Example 8 differs in that the preparation method of boron carbon nitride nanosheets includes the following steps: melamine and boric acid are mixed, heated to 900°C at a heating rate of 8°C / min under an argon atmosphere, kept at the temperature for 3 hours and then cooled to obtain boron carbon nitride material, the boron carbon nitride material is placed in water, ultrasonically treated at 200W for 45 minutes and then centrifuged to obtain boron carbon nitride nanosheets.

[0047] Example 9 Compared with Example 2, Example 9 differs in that the preparation method of boron carbon nitride nanosheets includes the following steps: melamine and boric acid are mixed, heated to 900°C at a heating rate of 8°C / min under an argon atmosphere, kept at the temperature for 3 hours and then cooled to obtain boron carbon nitride material, the boron carbon nitride material is placed in water, ultrasonically treated at 600W for 45 minutes and then centrifuged to obtain boron carbon nitride nanosheets.

[0048] Comparative Example 1 Compared with Example 2, Comparative Example 1 differs in that the ion sieve coating comprises the following raw materials in parts by weight: 15 parts of boron nitride carbon nanosheets, 10 parts of binder, and 2 parts of dispersant.

[0049] Comparative Example 2 Compared with Example 2, Comparative Example 2 differs in that the modified ceramic particles were replaced with an equal amount of alumina, and no modification treatment was performed.

[0050] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that the adhesive is a PVDF adhesive.

[0051] Comparative Example 4 Compared with Example 2, Comparative Example 4 differs in that γ-aminopropyltriethoxysilane is replaced with γ-mercaptopropyltriethoxysilane to obtain modified ceramic particles with a modification degree of 8 wt%.

[0052] Comparative Example 5 Compared with Example 2, Comparative Example 5 differs in that γ-aminopropyltriethoxysilane is replaced with γ-glycidoxypropyltrimethoxysilane to obtain modified ceramic particles with a modification degree of 8 wt%.

[0053] Comparative Example 6 Compared with Example 2, Comparative Example 6 differs in that the amino-containing self-crosslinking acrylate copolymer is replaced with an equal amount of amino-containing linear acrylate copolymer, and the amination rate is 8%; A method for preparing amino-containing linear acrylate copolymers includes the following steps: B1. Add 20 parts MMA, 5 parts BA, and 1.0 part emulsifier (sodium dodecylbenzenesulfonate) to deionized water, heat to 78°C, add 0.4 parts ammonium persulfate (APS) initiator, and react for 30 min to prepare seed emulsion; B2. Mix 20 parts MMA, 5 parts BA and 4.5 parts amino functional monomer (AM) to prepare a pre-emulsion. Add the pre-emulsion to the seed emulsion at a constant rate of 0.8 mL / min for 2.5 h to ensure that the amino monomer is uniformly copolymerized into the molecular chain. B3. After the addition is complete, keep warm at 75℃ for 1.2h, then add 0.1 parts of initiator ammonium persulfate to obtain an amino-containing linear acrylate copolymer with an amination rate of 8%.

[0054] Comparative Example 7 Compared with Example 2, Comparative Example 7 differs in that, in this example, boron nitride nanosheets are replaced with an equal amount of boron nitride material prepared by the following method, which includes the following steps: melamine and boric acid are mixed, heated to 900°C at a heating rate of 8°C / min under an argon atmosphere, held at that temperature for 3 hours and then cooled to obtain boron nitride material, and the boron nitride material is ground to obtain boron nitride material.

[0055] Experimental Example 1 The performance of the boron nitride carbon-based ion sieve coated membranes prepared in Examples 1-9 and Comparative Examples 1-7 was tested according to the following test methods.

[0056] 1. Liquid absorption rate and liquid retention rate: Tested according to the test methods specified in QB / T 2303.11-2008; 2. Ionic conductivity and thermal shrinkage: Tested according to the test methods specified in GB / T 36363-2018; 3. Capacity retention rate after 1500 charge-discharge cycles at 1C: The testing method is as follows: Testing equipment: constant temperature chamber + battery tester; set the temperature of the constant temperature chamber to 85℃ and stabilize it. Test subjects: button / pouch / cylindrical batteries containing boron nitride carbon-based ion sieve coated separators prepared in Examples 1-9 and Comparative Examples 1-7 were formed according to the standard process of the corresponding battery system (lithium-ion batteries are usually charged at a constant current of 0.05C to the cutoff voltage, constant voltage until the current is ≤0.01C, and then discharged at 0.05C to the discharge cutoff voltage after standing). Cyclic test: In a constant temperature chamber, maintain a constant temperature of 85℃ and perform charge-discharge cycles at a 1C rate. Charge to the upper limit cutoff voltage of the battery (constant current-constant voltage mode, stop when the current drops to 0.02C during the constant voltage stage), let stand for 10 minutes, then discharge at a constant current of 1C to the lower limit cutoff voltage, let stand for 10 minutes, and repeat this process for 1500 cycles. Calculate the capacity retention rate: Capacity retention rate (%) = (C1500 / C1) * 100%, where C1 is the discharge capacity of the first cycle and C1500 is the discharge capacity of the 1500th cycle. 4. Amount of metal ions deposited on the negative electrode surface: The test method is as follows: Pre-disassembly treatment: After the battery has been cycled 1500 times and discharged to the lower limit cutoff voltage, it is transferred to an argon atmosphere glove box (H2O<0.1ppm, O2<0.1ppm) for disassembly, and the negative electrode plate is removed. Electrode cleaning: Use a non-aqueous solvent corresponding to the battery system (dimethyl carbonate / DMC for lithium-ion batteries) to repeatedly rinse the surface of the negative electrode to remove residual electrolyte, and then vacuum dry in a glove box (temperature 50℃, time 18h) until constant weight. Weighing and digestion: The mass m1 of the dried negative electrode sheet was weighed using a high-precision analytical balance (precision ≥ 0.01 mg); the electrode sheet was cut into samples with a known area S, placed in a polytetrafluoroethylene digestion vessel, and a nitric acid-hydrofluoric acid mixed acid was added. The samples were then digested using a microwave digestion apparatus, cooled, and diluted to a volumetric flask with a certain volume V. Detection and Calculation: The concentration c (in mg / L) of the target metal ions in the diluted solution was determined using inductively coupled plasma optical emission spectrometry (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS); the amount of metal ions deposited on the negative electrode surface (mg / cm³) was also measured. 2 = (c*V) / S (The background metal ion content of the non-circulated negative electrode sheet in the same batch needs to be deducted). 5. Metal ion rejection rate: The test method is as follows: Preparation of metal ion solutions: Prepare standard metal ion solutions (such as those containing Li) that are compatible with the battery electrolyte system. + Fe 3 + Cu 2+ (equal carbonate solutions, concentration denoted as c0). Filtration experiment: Take a fixed volume V0 of metal ion standard solution and pass it through a target membrane sample of fixed area (pre-dried to constant weight) on a vacuum filtration device, and collect all the filtrate; Concentration detection: The concentration of metal ions (c1) in the filtrate was determined by ICP-OES / ICP-MS. Calculate the rejection rate: Metal ion rejection rate (%) = {1 - (C1*V1) / (C0*V0)} * 100%, where V1 is the volume of the filtrate (if there is no loss during filtration, then V1 = V0).

[0057] The test results are shown in Table 1: Table 1 Performance test results of Examples 1-9 and Comparative Examples 1-7

[0058] As shown in Table 1, comparing Example 2 with Comparative Examples 1-6, when the modifier for the ceramic particles is an aminosilane and the binder is an amino-containing self-crosslinking acrylate copolymer, the resulting boron nitride carbon-based ion sieve coating membrane exhibits a higher metal ion rejection rate. Non-aminosilane coupling agents lack amino groups on their surface and cannot form hydrogen bonds with amino-containing binders, resulting in insufficient coating stability. The epoxy groups do not synergistically interact with the amino binder, leading to performance inferior to the aminosilane-modified system. When the binder is an amino-containing linear acrylate copolymer, the lack of a self-crosslinking structure significantly reduces the coating's temperature resistance and electrolyte immersion resistance.

[0059] Comparing Examples 2 with Examples 4-7, it can be seen that when the ammoniation rate of the binder is 5%-12% and the modification degree of the modified ceramic particles is 5wt%-10wt%, the resulting boron nitride carbon-based ion sieve coating membrane has a higher metal ion rejection rate and better electrochemical performance. In the modified ceramic particles, if the modification is too low, the amount of amino grafting is insufficient, resulting in weak synergy with the binder and poor coating heat resistance and electrochemical properties; if the modification is too high, the silane coupling agent clogs the coating pores, significantly reducing ionic conductivity. Insufficient ammoniation rate leads to weak synergy between the binder and the modified alumina amino group, resulting in poor coating stability and heat resistance. Similarly, excessively high ammoniation rate results in excessive crosslinking density of the binder, reducing coating porosity and ionic conductivity.

[0060] Comparing Example 2 with Comparative Example 7 and Examples 8 and 9, it can be seen that ultrasonic exfoliation is a necessary condition for forming a layered structure and atomic-level sieve pores. Boron nitride materials without ultrasonic treatment cannot achieve efficient ion sieving. Excessive ultrasonic parameters will damage the integrity of the layers, resulting in excessive exfoliation and breakage of the layers, the absence of a continuous layered structure, and the collapse of the sieve pores, leading to the failure of the sieve pore structure.

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A boron nitride carbon-based ion sieve coating membrane, comprising a base membrane and an ion sieve coating coated on the surface of the base membrane, characterized in that, The ion sieve coating comprises the following raw materials in parts by weight: 10-20 parts of boron nitride carbon nanosheets, 65-80 parts of modified ceramic particles, 5-12 parts of binder, and 1-3 parts of dispersant. The modifier of the modified ceramic particles is an aminosilane, and the binder is an amino-containing self-crosslinking acrylate copolymer.

2. The boron nitride carbon-based ion sieve coating membrane according to claim 1, characterized in that, The aminosilane includes one or both of γ-aminopropyltriethoxysilane and γ-aminopropyltrimethoxysilane.

3. The boron nitride carbon-based ion sieve coating membrane according to claim 1, characterized in that, The amination rate of the adhesive is 5%~12%.

4. The boron nitride carbon-based ion sieve coating membrane according to claim 1, characterized in that, The preparation method of the boron nitride carbon nanosheets includes the following steps: melamine and boric acid are mixed, heated to 800~1000℃ under an argon atmosphere, kept at the temperature and then cooled to obtain boron nitride material, the boron nitride carbon material is placed in water, ultrasonically treated and then centrifuged to obtain boron nitride carbon nanosheets.

5. The boron nitride carbon-based ion sieve coating membrane according to claim 4, characterized in that, The molar ratio of melamine to boric acid is 1:1 to 1.

5.

6. The boron nitride carbon-based ion sieve coating membrane according to claim 4, characterized in that, The ultrasonic treatment power is 300~500W, and the ultrasonic treatment time is 30~60min.

7. The boron nitride carbon-based ion sieve coating membrane according to claim 4, characterized in that, The heating rate is 5~10℃ / min, and the holding time is 2~4h.

8. The boron nitride carbon-based ion sieve coating membrane according to claim 1, characterized in that, The dispersant is a polycarboxylate dispersant; The raw material for the modified ceramic particles has a particle size of 0.3μm to 0.5μm and a degree of modification of 5wt% to 10wt%.

9. A method for preparing a boron nitride carbon-based ion sieve coated membrane, used to prepare the boron nitride carbon-based ion sieve coated membrane according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Mix the dispersant with water, stir for the first time, disperse for the first time, and then add the boron nitride nanosheets; After the second stirring and the second dispersion, modified ceramic particles are added; after the third stirring and the third dispersion, a binder is added; after the fourth stirring and the fourth dispersion, a mixture is obtained. S2. The mixture is subjected to ultrasonic treatment to obtain a slurry; S3. The slurry is coated on at least one side of the base membrane and dried to obtain the boron nitride carbon-based ion sieve coated membrane.

10. The application of the boron nitride carbon-based ion sieve coated separator prepared by the method of preparing the boron nitride carbon-based ion sieve coated separator according to any one of claims 1 to 8 or claim 9 in a battery.

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