High-conductivity high-adhesion lithium ion battery diaphragm as well as preparation method and application thereof
By coating a lithium-ion battery separator with a combined coating of PVDF-HFP, ceramic powder, and MOFs, the problems of thermal shrinkage and insufficient safety of traditional separators at high temperatures are solved. This achieves synergistic optimization of high conductivity, high adhesion, and heat resistance, thereby improving the safety and cycle performance of lithium-ion batteries.
Patent Information
- Application Number
- CN202511914228.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-03-20
AI Technical Summary
Traditional lithium-ion battery separators are prone to thermal shrinkage and melting under high temperature or violent charge and discharge conditions, posing safety hazards. Furthermore, their puncture resistance and tensile modulus are insufficient, making it difficult to meet the requirements of high-safety power batteries.
A combination of coating materials, polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), ceramic powder, metal-organic framework materials (MOFs), and solid electrolytes is used to prepare a slurry via a stepwise method. Functional fillers are uniformly dispersed to construct high-speed lithium-ion transport channels and improve the mechanical properties and thermal stability of the coating, thereby enhancing the adhesion between the base film and the coating.
It achieves high ionic conductivity, excellent electrolyte wettability, good mechanical flexibility and heat resistance, enhances the separator's resistance to heat shrinkage and adhesion performance, and improves the safety and cycle performance of lithium-ion batteries.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery separator technology, specifically relating to a high-conductivity, high-adhesion lithium-ion battery separator, its preparation method, and its application. Background Technology
[0002] Lithium-ion batteries, with their advantages of high energy density and long cycle life, have been widely used in power batteries, 3C (computer, communication, and consumer electronics), and energy storage power stations. As one of the key materials in lithium-ion batteries, the performance of the separator directly affects the battery's safety, cycle performance, and energy density. Traditional lithium-ion battery separators are mainly polyolefin-based microporous membranes. While these materials have good mechanical properties, they still suffer from problems such as a low melting point (typically 130-160℃), poor electrolyte wettability, and poor adhesion to electrode materials. Under high temperatures or intense charge / discharge conditions, they are prone to thermal shrinkage or even melting, leading to safety hazards such as short circuits and thermal runaway.
[0003] Functional coating modification on base films has become a mainstream technological direction. Among them, polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) has been widely studied and applied as a coating material due to its excellent electrochemical stability, good electrolyte affinity, and certain adhesive properties. However, coatings using PVDF-HFP alone have significant shortcomings: firstly, the puncture resistance and tensile modulus are generally low, making it difficult to meet the stringent requirements of high-safety power batteries for puncture resistance and tensile strength; secondly, PVDF-HFP is a linear polymer, which is prone to softening and deformation at high temperatures and has insufficient thermal stability. The heat shrinkage resistance of coatings prepared from it mainly depends on the adhesion between PVDF-HFP and the base film, offering limited protection against battery thermal runaway.
[0004] Based on the above-mentioned technical problems, the present invention aims to provide a diaphragm with high ionic conductivity, excellent electrolyte wettability, good mechanical flexibility and good heat resistance, and a simple and controllable preparation method thereof. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high-conductivity, high-adhesion lithium-ion battery separator.
[0006] Another object of the present invention is to provide a method for preparing the above-mentioned high conductivity and high adhesion lithium-ion battery separator.
[0007] The objective of this invention is achieved through the following technical solution.
[0008] A high-conductivity, high-adhesion lithium-ion battery separator includes: a base film and a coating on the base film. The coating includes: polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), ceramic powder, functional filler, polyvinylpyrrolidone, and solid electrolyte. The functional filler is a metal-organic framework (MOF), and the ceramic powder is at least one of alumina and boehmite. The ratio of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), ceramic powder, functional filler, polyvinylpyrrolidone, and solid electrolyte by mass is (8~15):(1~5):(10~25):(0.8~2.25):(10~30).
[0009] In the above technical solution, the metal-organic framework material (MOF) is zeolite imidazole ester framework material-67 (ZIF-67).
[0010] In the above technical solution, the coating is obtained by applying a slurry, which includes: polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte. The solubilizer is a polyvinylpyrrolidone (PVP) solution. By mass parts, the ratio of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte is (8~15):(90~110):(1~3):(2~5):(1~5):(10~25):(2~5):(3~8):(10~30).
[0011] In the above technical solution, the preferred ratio of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte by mass parts is (11~13):(100~110):(1~3):(2~5):(1~5):(10~25):(2~5):(6~8):(25~30).
[0012] In the above technical solution, the solvent is N-methylpyrrolidone (NMP).
[0013] In the above technical solution, the dispersant is sodium dodecyl diphenyl ether disulfonate.
[0014] In the above technical solution, the pore-forming agent is a polyethylene glycol solution.
[0015] In the above technical solution, the content (solid content) of polyvinylpyrrolidone in the polyvinylpyrrolidone solution is 40~45wt%.
[0016] In the above technical solution, the adhesive is polybutyl acrylate emulsion, and the solid content of the polybutyl acrylate emulsion is 40~45wt%.
[0017] In the above technical solution, the solid electrolyte is at least one of NASICON-type solid electrolyte, perovskite-type solid electrolyte and garnet-type oxide solid electrolyte, preferably NASICON-type solid electrolyte.
[0018] In the above technical solution, the NASICON-type solid electrolyte is lithium aluminum titanium phosphate (LATP, Li 1.3 Al 0.3 Ti 1.7 (PO4)3).
[0019] The method for preparing the above-mentioned slurry includes the following steps:
[0020] Step 1: Mix polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and solvent until homogeneous to obtain the first solution;
[0021] Step 2: Mix the first solution and the dispersant until homogeneous to obtain the second solution;
[0022] Step 3: Mix the second solution, pore-forming agent, ceramic powder, functional filler and solubilizer until homogeneous to obtain the third solution;
[0023] Step 4: Mix the third solution, binder, and solid electrolyte until homogeneous to obtain a slurry;
[0024] The ratio of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte by mass parts is (8~15):(90~110):(1~3):(2~5):(1~5):(10~25):(2~5):(3~8):(10~30).
[0025] The above-mentioned method for preparing a high-conductivity, high-adhesion lithium-ion battery separator includes: coating a slurry onto at least one side of a base film, drying it for the first time to obtain a lithium-ion battery separator precursor, immersing the lithium-ion battery separator precursor in a coating solvent, drying it for the second time, obtaining a coating on the base film, and obtaining a high-conductivity, high-adhesion lithium-ion battery separator.
[0026] In the above technical solution, the thickness of the single-sided coating is 1~4μm.
[0027] In the above technical solution, the dipping solvent is N-methylpyrrolidone.
[0028] The application of the above-mentioned high-conductivity and high-adhesion lithium-ion battery separator in lithium-ion batteries.
[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0030] This invention utilizes a stepwise method to prepare the slurry, ensuring uniform dispersion of functional fillers (MOFs) and ceramic powder. The MOFs construct high-speed lithium-ion transport channels, while the ceramic powder simultaneously enhances the mechanical properties and thermal stability of the coating. This ultimately achieves synergistic optimization of the membrane's ionic conductivity, mechanical strength, and thermal stability, and achieves optimal performance balance under the specified raw material ratios, resulting in a lithium-ion battery separator with superior overall performance. Furthermore, the ceramic powder provides adhesive active sites, significantly enhancing the adhesion between the base film and coating, and between the coating and the electrode, giving the lithium-ion battery separator of this invention dual-state adhesion (dry and wet adhesion). The high-conductivity, high-adhesion lithium-ion battery separator of this invention exhibits high ionic conductivity, resulting in excellent cycle performance of the prepared lithium-ion battery. Detailed Implementation
[0031] The technical solution of the present invention will be further described below with reference to specific embodiments.
[0032] Polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP): The weight average molecular weight of polyvinylidene fluoride-hexafluoropropylene copolymer is 400,000 to 600,000, and the molar content of hexafluoropropylene monomer is 5% to 10%.
[0033] Polyvinylpyrrolidone (PVP) solution: K30, weight average molecular weight approximately 51320 Da. The content (solid content) of polyvinylpyrrolidone in the polyvinylpyrrolidone solution is 43.6 wt%.
[0034] Alumina: White powder, D10 is 0.205 μm, D50 is 0.385 μm, D90 is 1.001 μm, specific surface area is 19.4 m². 2 / g, average pore size 10.05nm.
[0035] Polybutyl acrylate emulsion: solid content is 40wt%, number average molecular weight is 234712.
[0036] Polyethylene glycol solution: solid content is 25wt%, number average molecular weight is 126543.
[0037] Sodium dodecyl diphenyl ether disulfonate: Chemical formula is C 24 H 32 O7S2Na2, with a molecular weight of 542.6, is a white powder with a purity of 99.0% and a density of approximately 1.161 g / ml (at 25°C). At 25°C and a concentration of 0.1%, its viscosity is 145 mPa·s.
[0038] The method for preparing ZIF-67 includes: dissolving 32 mmol of 2-methylimidazole and 16 mmol of cobalt acetate in 50 mL of anhydrous methanol, stirring each at room temperature for 5 min to obtain 2-methylimidazole solution and cobalt acetate solution respectively; rapidly pouring the 2-methylimidazole solution into the cobalt acetate solution to obtain a mixed solution; placing the mixed solution into a reaction vessel with a polytetrafluoroethylene liner, reacting at 60 °C for 24 h, and then centrifuging, washing, and drying to obtain ZIF-67.
[0039] The base film is a wet-process polyethylene film with a thickness of 5μm. It should be noted that base films of other thicknesses can also be used.
[0040] Coating adhesion strength test: The diaphragm was cut into a shape of 25mm×150mm, and 3M tape was used to stick it to the coating of the diaphragm. The 3M tape and the coating were then torn apart using a Shimadzu stretching machine to obtain the coating adhesion strength.
[0041] Ionic conductivity: tested at 25℃ and 40% relative humidity.
[0042] Heat shrinkage test: The transverse (TD) heat shrinkage rate and longitudinal (MD) heat shrinkage rate were determined according to the test method in GB / T 36363-2018 "Polyolefin separator for lithium-ion batteries". The size of the lithium-ion battery separator was 100mm×100mm, and the average value of 3 tests was taken as the heat shrinkage rate.
[0043] Puncture strength test: Use a needle with a diameter of 1 mm to puncture the septum at a speed of 100 mm / min, and record the maximum force value as the puncture strength.
[0044] Static contact angle (°) test: The static contact angle (°) test was conducted according to the test method in GB / T 30693-2014 "Measurement of contact angle between plastic film and water", and the average value of 5 tests was taken as the contact angle result.
[0045] Dry-state positive electrode bonding strength test: The separator was cut to a size of 25 mm * 150 mm, and the positive electrode sheet to a size of 25 mm * 150 mm; the temperature of the hot press was adjusted to 80℃ and the pressure to 1000 kg. The separator and the positive electrode sheet were preheated for 1 second and hot-pressed for 1 second using the hot press; the separator and the positive electrode sheet were peeled off using an electronic tensile testing machine until the tensile distance of the electronic tensile testing machine was 50 mm. The speed of the electronic tensile testing machine was 300 mm / min, and the peel angle was 180°. The dry-state positive electrode bonding strength = peel force divided by the tensile distance of the electronic tensile testing machine. Peel force: the average value of the force collected by the electronic tensile testing machine during the peeling process of the separator and the positive electrode sheet. The dry-state positive electrode bonding strength is calculated based on the data between 10 and 40 mm of tensile distance, that is, the dry-state positive electrode bonding strength = peel force between 10 and 40 mm of tensile distance divided by 30 mm. 10 sets of tests were conducted and the average value was taken. The positive electrode material in the positive electrode sheet is ternary lithium nickel cobalt aluminum oxide (LiNi). 0.8 Co 0.15 Al 0.05 O2).
[0046] Dry negative electrode bonding strength test: It is basically the same as the dry positive electrode bonding strength test, except that the "positive electrode" is replaced with the "negative electrode", and the negative electrode is a carbon-based graphite electrode (containing 91% carbon).
[0047] Wet positive electrode bonding strength test: After the dry positive electrode bonding strength test, the positive electrode and separator are placed in a 50mm*200mm aluminum foil sealed bag, 3mL of electrolyte is injected, and the bag is sealed to immerse the positive electrode and separator in the electrolyte at 25℃ for 64 hours. After removal, the surface free electrolyte is gently pressed and wiped with industrial wiping paper before the wet positive electrode bonding strength test: The separator and positive electrode are peeled until the tensile distance of the electronic tensile testing machine is 50mm. The testing speed was 300 mm / min, the peel angle was 180°, and the wet positive electrode bonding strength was calculated as: peel force divided by the tensile distance of the electronic tensile testing machine. Peel force: the average force collected by the electronic tensile testing machine during the peeling process of the separator and positive electrode. The wet positive electrode bonding strength was calculated based on data with tensile distances between 10 and 40 mm, i.e., wet positive electrode bonding strength = peel force between 10 and 40 mm divided by 30 mm. Ten sets of tests were conducted, and the average value was taken. The positive electrode material in the positive electrode was ternary lithium nickel cobalt aluminum oxide (LiNi). 0.8 Co 0.15 Al 0.05 O2).
[0048] Wet negative electrode bonding strength test: It is basically the same as the wet positive electrode bonding strength test, except that the "positive electrode" is replaced with the "negative electrode", and the negative electrode is a carbon-based graphite electrode (containing 91% carbon).
[0049] The electrolyte used in this invention is a mixture of electrolyte and solvent. The electrolyte is lithium hexafluorophosphate (LiPF6), and the solvent is a mixture of propylene carbonate (PC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). By mass, the ratio of propylene carbonate (PC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) is 1:1:1, and the concentration of the electrolyte in the electrolyte is 1.2 mol / L.
[0050] Examples 1-4
[0051] A method for preparing a slurry includes the following steps:
[0052] Step 1: Mix polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) and solvent, and stir at room temperature at a rotation speed of 1200 r / min and a revolution speed of 40 r / min for 15 min until homogeneous to obtain the first solution. The solvent is N-methylpyrrolidone (NMP) (moisture content of 60 ppm).
[0053] Step 2: Mix the first solution and the dispersant, and stir at room temperature at a rotation speed of 1200 r / min and a revolution speed of 40 r / min for 15 min until homogeneous to obtain the second solution, wherein the dispersant is sodium dodecyl diphenyl ether disulfonate.
[0054] Step 3: Mix the second solution, pore-forming agent, ceramic powder, functional filler and solubilizer, and stir at 2000 rpm for 2 hours at room temperature until homogeneous to obtain the third solution. The pore-forming agent is polyethylene glycol solution, the ceramic powder is alumina, the functional filler is metal-organic framework material (ZIF-67), and the solubilizer is polyvinylpyrrolidone (PVP) solution.
[0055] Step 4: Mix the third solution, binder, and solid electrolyte, and stir at 3000 rpm for 1 hour at room temperature until homogeneous to obtain a slurry. The binder is polybutyl acrylate emulsion, and the solid electrolyte is a NASICON-type solid electrolyte (lithium aluminum titanium phosphate (LiTi)). 1.3 Al 0.3 Ti 1.7 (PO4)3), lithium titanium aluminum phosphate has a particle size ≤1μm and a D50 of 0.27μm;
[0056] The ratio of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder, and solid electrolyte by mass parts is X. The value of X is shown in Table 1.
[0057] Table 1
[0058]
[0059] Example 5
[0060] A method for preparing a slurry is basically the same as in Example 2, except that: the solid electrolyte is a NASICON-type solid electrolyte (lithium aluminum titanium phosphate (LiTi)). 1.3 Al 0.3 Ti 1.7 Replace "(PO4)3))" with "The solid electrolyte is a perovskite-type solid electrolyte (lithium lanthanum titanate (Li)" 0.33 La 0.56 TiO3). The particle size of lithium lanthanum titanate is: D50 is 0.27 μm.
[0061] Comparative Example 1
[0062] A method for preparing the slurry is basically the same as in Example 4, except that "metal-organic framework material (ZIF-67)" is replaced with "lithium aluminum titanium phosphate (LiTi)". 1.3 Al 0.3 Ti 1.7 (PO4)3).
[0063] Comparative Example 2
[0064] A method for preparing a slurry is basically the same as that in Example 4, except that no solubilizer is added.
[0065] Comparative Example 3
[0066] A method for preparing a slurry is basically the same as that in Example 4, except that in Comparative Example 3, the ratio of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte by mass parts is 18:100:2:3:3:18:3:5:5.
[0067] Comparative Example 4
[0068] A method for preparing the slurry is basically the same as in Example 4, except that "alumina" is replaced with "silicon dioxide". The particle size of the silicon dioxide is D50 of 0.45 μm.
[0069] Examples 6-10 and Comparative Examples 5-8
[0070] A method for preparing a lithium-ion battery separator includes: applying a slurry to both sides of a base film by dip coating; first drying (drying at 60°C for 1 min) to obtain a lithium-ion battery separator precursor; using N-methylpyrrolidone (NMP) with a water content of 80 ppm as the dip coating solvent; immersing the lithium-ion battery separator precursor in the dip coating solvent for 20 min to disperse the pore-forming agent polyethylene glycol in the dip coating solvent; and removing the polyethylene glycol after a second drying (drying at 90°C for 20 min) to obtain a coating with a single-sided thickness of 2 μm, thereby obtaining a lithium-ion battery separator. The slurry is one of the slurries prepared in Examples 1-5 and Comparative Examples 1-4 (the lithium-ion battery separator prepared based on the slurry in Examples 1-5 is a high-conductivity, high-adhesion lithium-ion battery separator).
[0071] Table 2
[0072]
[0073] The performance of the lithium-ion battery separators prepared in Examples 6-10 and Comparative Examples 5-8 was tested, and the results are shown in Tables 3 and 4.
[0074] Table 3
[0075]
[0076] Table 4
[0077]
[0078] The lithium-ion battery separators of Examples 6-10 and Comparative Examples 5-8 were used to fabricate batteries. Specifically, this involved sandwiching the lithium-ion battery separator between the positive and negative electrode sheets, assembling it into a CR2032 button cell casing, and encapsulating it to obtain lithium-ion button cells (CR2032 button cells) corresponding to the lithium-ion battery separators of Examples 6-10 and Comparative Examples 5-8, respectively. The method for obtaining the positive electrode sheet included: using N-methylpyrrolidone and lithium nickel cobalt aluminum oxide (LiNi... 0.8 Co 0.15 Al 0.05 O2), conductive carbon black and positive electrode binder (polyvinylidene fluoride, PVDF) are mixed (by mass, the ratio of N-methylpyrrolidone, lithium nickel cobalt aluminum oxide, conductive carbon black and positive electrode binder is 10:8:1:1), stirred at a rotation speed of 1500 r / min and a revolution speed of 20 r / min for 10 min, and then sonicated at a frequency of 7 kHz for 30 min to obtain positive electrode slurry. 1.5 g of positive electrode slurry is coated on an aluminum foil substrate (91.5 mm * 1 m) and dried in a constant temperature oven to form a positive electrode coating on the aluminum foil substrate. Rolling is then used to firmly press the positive electrode coating onto the aluminum foil substrate to obtain the positive electrode sheet.
[0079] The preparation method of the negative electrode sheet includes: mixing N-methylpyrrolidone, graphite, Ketjen black and negative electrode binder (styrene-butadiene latex, SBR) (by mass parts, the ratio of N-methylpyrrolidone, graphite, Ketjen black and negative electrode binder is 10:8:0.8:1.2), stirring at a rotation speed of 1500 r / min and a revolution speed of 20 r / min for 10 min, and then sonicating at a frequency of 7 kHz for 30 min to obtain a negative electrode slurry. 1.5 g of the negative electrode slurry is coated on a copper foil substrate (91.5 mm * 1.2 m), dried in a constant temperature oven to form a negative electrode coating on the copper foil substrate, and rolled to firmly press the negative electrode coating onto the copper foil substrate to obtain the negative electrode sheet.
[0080] The lithium-ion button batteries made based on the lithium-ion battery separators of Examples 6-10 and Comparative Examples 5-8 were subjected to cycle performance tests: 500 charge-discharge cycles were performed under 0.5C conditions, and the capacity retention rates are shown in Table 5.
[0081] Table 5
[0082]
[0083] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.
Claims
1. A high-conductivity, high-adhesion lithium-ion battery separator, characterized in that, include: The base film and the coating on the base film, the coating comprising: polyvinylidene fluoride-hexafluoropropylene copolymer, ceramic powder, functional filler, polyvinylpyrrolidone and solid electrolyte, wherein the functional filler is a metal-organic framework material, the ceramic powder is at least one of alumina and boehmite, and the ratio of polyvinylidene fluoride-hexafluoropropylene copolymer, ceramic powder, functional filler, polyvinylpyrrolidone and solid electrolyte by mass parts is (8~15):(1~5):(10~25):(0.8~2.25):(10~30).
2. The high conductivity and high adhesion lithium-ion battery separator according to claim 1, characterized in that, The metal-organic framework material is ZIF-67.
3. The high conductivity and high adhesion lithium-ion battery separator according to claim 2, characterized in that, The coating is obtained by applying a slurry, which includes: polyvinylidene fluoride-hexafluoropropylene copolymer, solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte. By mass parts, the ratio of polyvinylidene fluoride-hexafluoropropylene copolymer, solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte is (8~15):(90~110):(1~3):(2~5):(1~5):(10~25):(2~5):(3~8):(10~30).
4. The high conductivity and high adhesion lithium-ion battery separator according to claim 3, characterized in that, The solvent is N-methylpyrrolidone; the dispersant is sodium dodecyl diphenyl ether disulfonate; the pore-forming agent is polyethylene glycol solution; the solubilizer is polyvinylpyrrolidone solution; and the binder is polybutyl acrylate emulsion.
5. The high conductivity and high adhesion lithium-ion battery separator according to claim 3, characterized in that, The solid electrolyte is at least one of NASICON-type solid electrolyte, perovskite-type solid electrolyte, and garnet-type oxide solid electrolyte.
6. The high conductivity and high adhesion lithium-ion battery separator according to claim 5, characterized in that, The NASICON-type solid electrolyte is lithium titanium aluminum phosphate.
7. The high conductivity and high adhesion lithium-ion battery separator according to claim 3, characterized in that, The method for preparing the slurry includes the following steps: Step 1: Mix the polyvinylidene fluoride-hexafluoropropylene copolymer and solvent until homogeneous to obtain the first solution; Step 2: Mix the first solution and the dispersant until homogeneous to obtain the second solution; Step 3: Mix the second solution, pore-forming agent, ceramic powder, functional filler and solubilizer until homogeneous to obtain the third solution; Step 4: Mix the third solution, binder, and solid electrolyte until homogeneous to obtain a slurry; The ratio of polyvinylidene fluoride-hexafluoropropylene copolymer, solvent, dispersant, pore-forming agent, ceramic powder, functional filler, solubilizer, binder and solid electrolyte by mass parts is (8~15):(90~110):(1~3):(2~5):(1~5):(10~25):(2~5):(3~8):(10~30).
8. The method for preparing the high-conductivity, high-adhesion lithium-ion battery separator as described in claim 1, characterized in that, include: The slurry is coated on at least one side of the base film and dried for the first time to obtain a lithium-ion battery separator precursor. The lithium-ion battery separator precursor is then immersed in a coating solvent and dried for the second time to obtain a coating on the base film, resulting in a high-conductivity and high-adhesion lithium-ion battery separator.
9. The preparation method according to claim 8, characterized in that, The thickness of the single-sided coating is 1~4μm.
10. The application of the high conductivity and high adhesion lithium-ion battery separator as described in claim 1 in lithium-ion batteries.