Aqueous coating slurry, lithium battery separator and method for preparing the same

Abstract

The application discloses a kind of aqueous coating slurry, lithium battery diaphragm and its preparation method, the preparation of aqueous coating slurry includes successively: sulfonic acid group furan polyamide is diluted into 2wt%~5wt% solid content dilute solution;The dilute solution is mixed with water, then emulsified, and the organic solvent in the sulfonic acid group furan polyamide is removed, to obtain a mixed solution;The mixed solution is mixed with inorganic particles, adhesive, to obtain aqueous coating slurry.The aqueous coating slurry is coated on the base film to make lithium battery diaphragm, which can improve the wettability of the diaphragm to electrolyte, while enhancing the air permeability and manganese ion absorption of the diaphragm.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery separator, in particular to a water-based coating slurry, a lithium battery separator and a preparation method thereof. BACKGROUND

[0002] In recent years, with the rapid development of new energy vehicles, lithium batteries have become a crucial research field. As the power source of new energy vehicles, the safety and performance of lithium batteries are increasingly valued. The separator plays a key role in the battery, mainly separating the positive and negative electrodes to prevent short circuits, while allowing ions to pass through to complete the charging and discharging process of the battery.

[0003] Most of the existing lithium battery coated separators on the market are prepared based on two coating methods, namely oil coating and water coating. Oil coating has greater environmental hazards and high cost; although water coating is low in cost, few use high molecular materials as the main coating, mostly using alumina and boehmite as the main body, and adding high molecular adhesives as the coating material. Most of the high molecular materials suitable for water coating are in the form of solvent or viscous emulsion, which has the characteristics of improving adhesion but cannot be used as the main body of water coating. At the same time, most of the water-coated separators have poor affinity for electrolyte, resulting in poor wettability of electrolyte, poor liquid absorption and liquid retention rate of the separator, and poor cycle performance of the battery. SUMMARY

[0004] Therefore, one object of the present application is to provide a water-based coating slurry, a lithium battery separator and a preparation method thereof. The water-based coating slurry is coated on the base film to form a lithium battery separator, which can improve the wettability of the separator to the electrolyte, and enhance the air permeability and manganese ion absorption of the separator.

[0005] In one aspect of the present application, a preparation method of a water-based coating slurry is provided. According to an embodiment of the present application, the method comprises:

[0006] Step 1, diluting the sulfonic acid-based furan polyamide into a dilute solution with a solid content of 2wt% to 5wt%;

[0007] Step 2, mixing the dilute solution with water, then emulsifying, and removing the organic solvent in the sulfonic acid-based furan polyamide to obtain a mixed solution;

[0008] Step 3, mixing the mixed solution with inorganic particles and adhesives to obtain a water-based coating slurry;

[0009] The sulfonic acid-based furan polyamide is prepared by the following method:

[0010] The sulfonated diamine, triethylamine and an organic solvent are mixed under an inert gas atmosphere, and then the mixture is reacted at 60-70 DEG C to obtain a sulfonic acid ammonium salt diamine solution; the sulfonic acid ammonium salt diamine solution is cooled to -10-20 DEG C, and furan dicarboxylic chloride is added to obtain a slurry; the slurry is mixed with a base to obtain a sulfonic acid furan polyamide.

[0011] The sulfonic acid furan polyamide is diluted to obtain a diluted solution, which is then mixed with water, further emulsified, and then separated from residual organic solvent by using a separation device to obtain an aqueous mixed solution, which is then mixed with inorganic particles and adhesives to obtain an aqueous coating slurry.

[0012] The sulfonic acid furan polyamide is prepared by mixing sulfonated diamine, triethylamine and an organic solvent, and then reacting at 60-70 DEG C; the sulfonated diamine and triethylamine react to generate sulfonic acid ammonium salt diamine, which has stronger polarity and can be better dissolved in polar organic solvents, and can polymerize with furan dicarboxylic chloride to graft sulfonic acid groups to the polyamide and increase the content of sulfonic acid groups in the polyamide.

[0013] The carbonyl and sulfonic acid groups in the aqueous coating slurry have good affinity to electrolyte, can make the electrolyte quickly diffuse along the molecular chain, and the hollow structure can further absorb and retain electrolyte; and the long chain formed by polymerization can retain its shrinkage capacity in a high temperature environment.

[0014] In summary, the air permeability and manganese ion absorption amount of the lithium battery separator are improved, the aqueous coating slurry does not contain organic solvents, the furan dicarboxylic chloride used as raw material can be derived from bio-based raw materials, is environmentally friendly, the hydrophilic performance of the aqueous coating slurry is enhanced, and the application prospect is more promising.

[0015] In addition, the aqueous coating slurry preparation method according to the above embodiments of the present application can also have the following additional technical features:

[0016] In some embodiments of the present application, the mass ratio of the diluted solution to water is (1.5-10):1.

[0017] In some embodiments of the present application, the aqueous coating slurry is further mixed with a thickening agent, a dispersing agent, a wetting agent and an adhesion promoter; thus, the dispersibility, adhesion and other properties of the aqueous coating slurry can be further improved.

[0018] In some embodiments of the present application, the mass of the mixed solution is 5% to 30% of the mass of the aqueous coating slurry, the mass of the inorganic particles is 5% to 20% of the mass of the mixed solution, the mass of the adhesive is 1% to 10% of the mass of the mixed solution, the mass of the thickening agent is 0.01% to 0.1% of the mass of the aqueous coating slurry, the mass of the dispersing agent is 0.5% to 1.5% of the mass of the mixed solution, the mass of the wetting agent is 0.01% to 1% of the mass of the aqueous coating slurry, and the mass of the adhesion promoter is 0.01% to 0.05% of the mass of the aqueous coating slurry.

[0019] In some embodiments of the present application, the inorganic particles are one or both of alumina and boehmite with a particle size of 100 nm to 5 μm, the adhesive is one or more of polyacrylate, modified polyacrylate, and modified polyvinyl alcohol, the thickening agent is sodium carboxymethyl cellulose, the dispersing agent is one or more of acrylate, modified acrylate, and acrylic polymer, the wetting agent is one or both of fatty alcohol polyoxyethylene ether and polyether-modified organosilicon, and the adhesion promoter is a sulfate salt anionic surfactant.

[0020] In some embodiments of the present application, the molar ratio of the triethylamine to the sulfonated diamine is (1.1 to 2.5):1, and the molar ratio of the sulfonated diamine to the furandicarboxylic dichloride is (1 to 2.5):1.

[0021] In some embodiments of the present application, the mass ratio of the organic solvent to the sulfonated diamine is (3 to 11):1.

[0022] In some embodiments of the present application, the inert gas is one or more of nitrogen, helium, and argon, the organic solvent is one or more of toluene, N,N-dimethylacetamide, N-methylpyrrolidone, N,N-dimethylformamide, dichloromethane, and dichloroethane, and the sulfonated diamine is one or more of 2,5-diaminobenzenesulfonic acid and 4,4'-diamino-3,3'-biphenyl disulfonic acid.

[0023] In some embodiments of the present application, the pH of the slurry after mixing with a base is 6 to 8, and the base includes at least one of lithium hydroxide, calcium hydroxide, and sodium hydroxide.

[0024] In a second aspect of the present application, an aqueous coating slurry prepared by the above method is provided. Thus, the aqueous coating slurry does not contain an organic solvent, and the furandicarboxylic dichloride used as a raw material can come from a bio-based raw material, is environmentally friendly, and has enhanced hydrophilic properties, and thus has a broader application prospect.

[0025] In a third aspect of the present application, a preparation method of the lithium battery separator is provided. The aqueous coating slurry is coated on at least one side of the base film, and then dried to obtain the lithium battery separator.

[0026] In a fourth aspect of the present application, a lithium battery separator prepared by the above method is provided. Thus, the lithium battery separator has strong wettability to electrolyte, and the film breaking temperature and air permeability are improved. When applied to the lithium battery, the safety performance of the lithium battery is improved.

[0027] Additional aspects and advantages of the present application will be made apparent from the following description. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0029] Embodiment 1

[0030] Preparation of the aqueous polyamide lithium battery separator:

[0031] Step one: under a nitrogen atmosphere, 10 kg of dimethylacetamide (organic solvent) is added to a reaction kettle, and then 1 kg of triethylamine and 1 kg of 2,5-diaminobenzene sulfonic acid (sulfonated diamine) are added to react at 60°C to obtain an ammonium sulfonate diamine solution; the ammonium sulfonate diamine solution is cooled to -10°C, and then 1 kg of furan diacyl chloride is added in portions for polymerization reaction, which is completed after 4 hours, and then 0.75 kg of calcium hydroxide (base) is added for neutralization, and after the neutralization is completed, a sulfonic acid furan polyamide is obtained.

[0032] Step two: the sulfonic acid furan polyamide is diluted to 2 wt% solid content with dimethylacetamide, and then 10.8 times the mass of water is added, which is uniformly dispersed by stirring, and then an equal amount of water is emulsified by an emulsifying pump, and then dimethylacetamide is removed by a ceramic membrane separation device to obtain a mixed solution.

[0033] Step three: 14 kg of deionized water, 6 kg of the mixed solution, and 0.06 kg of modified acrylate (dispersant) are added to a stirring tank and high-speed dispersed for 30 minutes; after the dispersion is completed, 0.6 kg of aluminum oxide (inorganic particles) with a particle size of 0.6 μm is added and high-speed dispersed for 1 hour; after the dispersion is completed, a sand mill is used for grinding 3 times to obtain the aqueous coating slurry.

[0034] The water-based coating slurry is coated on the PE base film with a total thickness of 4 μm, and a lithium battery separator is obtained after drying.

[0035] Example 2

[0036] Preparation of a water-based polyamide lithium battery separator:

[0037] Step one: under a nitrogen atmosphere, 10 kg of dimethylacetamide (organic solvent) is added to a reaction kettle, then 1 kg of triethylamine and 1 kg of 4,4'-diamino-3,3'-biphenyl disulfonic acid (sulfonated diamine) are added to react at a temperature of 65°C to obtain an ammonium sulfonate diamine solution; the ammonium sulfonate diamine solution is cooled to -5°C, then 1 kg of furan diacyl chloride is added in portions for polymerization, after 4 hours of polymerization, 0.75 kg of calcium hydroxide (base) is added for neutralization, and after neutralization is complete, a sulfonic acid-based furan polyamide is obtained.

[0038] Step two: the sulfonic acid-based furan polyamide is diluted to 2 wt% solid content with dimethylacetamide, then 9.8 times the mass of water is added, after stirring and dispersing uniformly, an equal amount of water is emulsified by an emulsifying pump, dimethylacetamide is removed by a ceramic membrane separation device, and a mixed solution is obtained.

[0039] Step three: 14 kg of deionized water, 6 kg of the mixed solution, and 0.06 kg of modified acrylate (dispersant) are added to a stirring tank and high-speed dispersed for 30 minutes; after dispersion is complete, 0.6 kg of aluminum oxide (inorganic particles) with a particle size of 0.6 μm is added and high-speed dispersed for 1 hour; after dispersion is complete, a sand mill is used for grinding 3 times, and a water-based coating slurry is obtained.

[0040] The water-based coating slurry is coated on the PE base film with a total thickness of 4 μm, and a lithium battery separator is obtained after drying.

[0041] Example 3

[0042] Preparation of a water-based polyamide lithium battery separator:

[0043] Step one: under a nitrogen atmosphere, 10 kg of dimethylacetamide (organic solvent) is added to a reaction kettle, then 1 kg of triethylamine and 1 kg of 2,5-diaminobenzenesulfonic acid (sulfonated diamine) are added to react at a temperature of 70°C to obtain an ammonium sulfonate diamine solution; the ammonium sulfonate diamine solution is cooled to -5°C, then 1 kg of furan diacyl chloride is added in portions for polymerization, after 4 hours of polymerization, 0.75 kg of calcium hydroxide (base) is added for neutralization, and after neutralization is complete, a sulfonic acid-based furan polyamide is obtained.

[0044] Step two: dilute the sulfonic acid furan polyamide to 3wt% solid content with dimethylacetamide, then add 5.4 times mass of water with solid content, stir and disperse uniformly, then emulsify with equal amount of water through an emulsifying pump, and then remove dimethylacetamide using a ceramic membrane separation device to obtain a mixed solution.

[0045] Step three: add 14 kilograms of deionized water, 6 kilograms of the mixed solution, and 0.06 kilograms of modified acrylate (dispersant) into a stirring tank and high-speed disperse for 30 minutes; after dispersion is completed, add 0.6 kilograms of alumina with a particle size of 0.6 μm (inorganic particles) and high-speed disperse for 1 hour; after dispersion is completed, use a sand mill to grind 3 times, and after grinding is completed, add 0.3 kilograms of modified polyacrylate (adhesive) and medium-speed disperse for 30 minutes; after dispersion is completed, add 0.01 kilograms of sodium carboxymethyl cellulose (thickening agent) and medium-speed disperse for 30 minutes; after dispersion is completed, add 0.004 kilograms of polyether-modified silicone (wetting agent) and 0.004 kilograms of sulfate anionic surfactant (adhesion promoter) and stir for 20 minutes to obtain an aqueous coating slurry.

[0046] Coat the aqueous coating slurry on a PE-based film to obtain a lithium battery separator with a total thickness of 4 μm.

[0047] Example 4

[0048] Preparation of an aqueous polyamide lithium battery separator:

[0049] Step one: under a nitrogen atmosphere, add 10 kilograms of dimethylacetamide (organic solvent) into a reaction kettle, and then add 1 kilogram of triethylamine and 1 kilogram of 2,5-diaminobenzenesulfonic acid (sulfonated diamine) to perform a reaction at a temperature of 65 °C to obtain an ammonium sulfonate diamine solution; cool the ammonium sulfonate diamine solution to 5 °C, and then add 1 kilogram of furan diacyl chloride in portions to perform a polymerization reaction, and after 4 hours of reaction, add 0.75 kilograms of calcium hydroxide (base) to perform neutralization, and after neutralization is completed, obtain sulfonic acid furan polyamide.

[0050] Step two: dilute the sulfonic acid furan polyamide to 3.5wt% solid content with dimethylacetamide, add 10.8 times mass of water with solid content, stir and disperse uniformly, and then emulsify with equal amount of water through an emulsifying pump, and then remove dimethylacetamide using a ceramic membrane separation device to obtain a mixed solution.

[0051] Step three: add 15 kg of deionized water, 6 kg of mixed solution, 0.06 kg of modified acrylate (dispersant) into the stirring tank and high-speed disperse for 30 minutes; after dispersion is completed, add 0.6 kg of boehmite (inorganic particles) with a particle size of 0.6 μm and high-speed disperse for 1 hour; after dispersion is completed, use a sand mill to grind 3 times, after grinding is completed, add 0.6 kg of modified polyacrylate (adhesive) and medium-speed disperse for 30 minutes, after dispersion is completed, add 0.01 kg of sodium carboxymethyl cellulose (thickening agent) and medium-speed disperse for 30 minutes; after dispersion is completed, add 0.004 kg of polyether modified silicone (wetting agent) and 0.004 kg of sulfate anionic surfactant (adhesion promoter) and stir for 20 minutes to obtain the coating slurry of the aqueous aramid.

[0052] Coat the aqueous coating slurry on the PE-based film to obtain a lithium battery separator with a total thickness of 4 μm.

[0053] Example 5

[0054] Preparation of the aqueous polyamide lithium battery separator:

[0055] Step one: under a nitrogen atmosphere, add 10 kg of dimethylacetamide (organic solvent) into a reaction kettle, then add 1 kg of triethylamine and 1 kg of 2,5-diaminobenzenesulfonic acid (sulfonated diamine) and react at a temperature of 65 °C to obtain an ammonium sulfonate diamine solution; cool the ammonium sulfonate diamine solution to 5 °C, then add 1 kg of furan diacyl chloride in portions and perform a polymerization reaction, after 4 hours of polymerization, add 0.75 kg of calcium hydroxide (base) to perform neutralization, after neutralization is completed, the sulfonic acid-based furan polyamide can be obtained.

[0056] Step two: dilute the sulfonic acid-based furan polyamide to 4 wt% solid content with dimethylacetamide, add 10.8 times the mass of water based on the solid content, stir and disperse uniformly, then emulsify with an equal amount of water through an emulsifying pump, then use a ceramic membrane separation device to remove dimethylacetamide to obtain a mixed solution.

[0057] Step three: add 15 kg of deionized water, 6 kg of mixed solution, 0.05 kg of modified acrylate (dispersant) into the stirring tank and high-speed disperse for 30 minutes; after dispersion is completed, add 0.6 kg of alumina (inorganic particles) with a particle size of 0.6 μm and high-speed disperse for 1 hour; after dispersion is completed, use a sand mill to grind 3 times, after grinding is completed, add 0.9 kg of modified polyacrylate (adhesive) and medium-speed disperse for 30 minutes, after dispersion is completed, add 0.01 kg of sodium carboxymethyl cellulose (thickening agent) and medium-speed disperse for 30 minutes; after dispersion is completed, add 0.004 kg of polyether modified silicone (wetting agent) and 0.004 kg of sulfate anionic surfactant (adhesion promoter) and stir for 20 minutes to obtain the coating slurry of the aqueous aramid.

[0058] The water-based coating slurry is coated on the PE base film with a total thickness of 4 μm, and a lithium battery separator is obtained after drying.

[0059] Example 6

[0060] Preparation of a water-based polyamide lithium battery separator:

[0061] Step one: under a nitrogen atmosphere, 10 kg of dimethylacetamide (organic solvent) is added to a reaction kettle, followed by 1 kg of triethylamine and 1 kg of 2,5-diaminobenzene sulfonic acid (sulfonated diamine) to react at a temperature of 65°C to obtain an ammonium sulfonate diamine solution; the ammonium sulfonate diamine solution is cooled to 10°C, and 1 kg of furan diacyl chloride is added in portions for polymerization, and after 4 hours of polymerization, 0.75 kg of calcium hydroxide (base) is added for neutralization, and after neutralization is complete, a sulfonic acid-based furan polyamide is obtained.

[0062] Step two: the sulfonic acid-based furan polyamide is diluted to 4 wt% solid content with dimethylacetamide, 10.8 times the mass of water is added, and stirred and dispersed uniformly, and then emulsified with an equal amount of water using an emulsifying pump, and then the dimethylacetamide is removed using a ceramic membrane separation device to obtain a mixed solution.

[0063] Step three: 14 kg of deionized water, 6 kg of the mixed solution, 0.05 kg of modified acrylate (dispersant) are added to a stirring tank and high-speed dispersed for 30 minutes; after dispersion is complete, 0.6 kg of alumina (inorganic particles) with a particle size of 0.6 μm is added and high-speed dispersed for 1 hour; after dispersion is complete, the sand mill is ground 3 times, and after grinding is complete, 0.3 kg of modified polyvinyl alcohol (adhesive) is added and medium-speed dispersed for 30 minutes, and after dispersion is complete, 0.01 kg of sodium carboxymethyl cellulose (thickening agent) is added and medium-speed dispersed for 30 minutes; after dispersion is complete, 0.004 kg of polyether-modified organosilicon (wetting agent) and 0.004 kg of sulfate anionic surfactant (adhesion promoter) are added and stirred for 20 minutes to obtain a water-based coating slurry.

[0064] The water-based coating slurry is coated on the PE base film with a total thickness of 4 μm, and a lithium battery separator is obtained after drying.

[0065] Example 7

[0066] Preparation of a water-based polyamide lithium battery separator:

[0067] Step 1: Under a nitrogen atmosphere, 10 kg of dimethylacetamide (organic solvent) was added to a reaction kettle, followed by 1 kg of triethylamine and 1 kg of 2,5-diaminobenzene sulfonic acid (sulfonated diamine) to react at 65°C to obtain a sulfonic acid ammonium salt diamine solution; the sulfonic acid ammonium salt diamine solution was cooled to 20°C, and then 1 kg of furan diacyl chloride was added in portions for polymerization, and after 6 hours of polymerization, 0.75 kg of calcium hydroxide (base) was added for neutralization, and after neutralization was complete, a sulfonic acid furan polyamide was obtained.

[0068] Step 2: The sulfonic acid furan polyamide was diluted to 5 wt% solid content with dimethylacetamide, 10.8 times the mass of water was added, and stirred and dispersed uniformly, and then emulsified with an equal amount of water using an emulsifying pump, and then dimethylacetamide was removed using a ceramic membrane separation device to obtain a mixed solution.

[0069] Step 3: 14 kg of deionized water, 6 kg of the mixed solution, 0.05 kg of modified acrylate (dispersant) were added to a stirring tank and high-speed dispersed for 30 minutes; after dispersion was complete, 0.6 kg of alumina (inorganic particles) with a particle size of 0.6 μm was added and high-speed dispersed for 1 hour; after dispersion was complete, a sand mill was used for grinding 3 times, and after grinding was complete, 0.3 kg of polyacrylate (adhesive) was added and medium-speed dispersed for 30 minutes, and after dispersion was complete, 0.01 kg of sodium carboxymethyl cellulose (thickening agent) was added and medium-speed dispersed for 30 minutes; after dispersion was complete, 0.004 kg of polyether-modified silicone (wetting agent) and 0.004 kg of sulfate anionic surfactant (adhesion promoter) were added and stirred for 20 minutes to obtain an aqueous coating slurry.

[0070] The aqueous coating slurry was coated on a base film to a total thickness of 4 μm, and after drying and baking, a lithium battery separator was obtained.

[0071] Comparative Example 1

[0072] Triethylamine was replaced with m-phenylenediamine, and the rest of the process was the same as Example 1, and finally a lithium battery separator was obtained.

[0073] Comparative Example 2

[0074] Commercial aramid separator

[0075] The lithium battery separator membranes produced in Examples 1-7 and Comparative Examples 1-2 were subjected to the following performance tests, and the instruments and test methods used are shown in Table 1, and the performance test results are shown in Table 2.

[0076] Table 1 Test instruments and test methods for the separator membranes produced in the examples and comparative examples

[0077]

[0078] Table 2 Performance of the separator membranes obtained in the examples and comparative examples

[0079]

[0080] From the data of examples 1-7 and comparative examples 1-2, it can be seen that the lithium battery separator prepared by the present application has significantly higher wettability to electrolyte, high liquid retention efficiency, and stronger gas permeability and manganese ion absorption capacity.

[0081] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and modified by those skilled in the art without contradiction.

[0082] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A method for preparing a lithium battery separator, characterized in that, The aqueous coating slurry is coated onto at least one side of a base film and then dried to obtain the final product. The method for preparing the aqueous coating slurry comprises: Step 1: Dilute the sulfonated furan polyamide to a 2wt%~5wt% solid content solution, wherein the sulfonated furan polyamide is prepared by the following method: Under an inert gas atmosphere, sulfonated diamine, triethylamine and organic solvent are mixed and then heated to 60-70°C to react, yielding a sulfonate diamine solution; the sulfonate diamine solution is cooled to -10°C to 20°C, and furanyl chloride is added to obtain a slurry; the slurry is then mixed with an alkali to obtain sulfonate-based furan polyamide; Step 2: Mix the diluted solution with water, then emulsify it, and then remove the organic solvent from the sulfonated furan polyamide to obtain a mixed solution; Step 3: Mix the mixed solution with deionized water, inorganic particles, and a dispersant to obtain an aqueous coating slurry, wherein the dispersant is one or more of modified acrylates and acrylic polymers.

2. The method for preparing a lithium battery separator according to claim 1, characterized in that, The mass ratio of the diluted solution to water is (1.5~10):

1.

3. The method for preparing a lithium battery separator according to claim 1, characterized in that, The water-based coating slurry is further mixed with thickeners, adhesives, wetting agents, and tackifiers; The mass of the mixed solution is 5% to 30% of the mass of the aqueous coating slurry, the mass of the inorganic particles is 5% to 20% of the mass of the mixed solution, the mass of the adhesive is 1% to 10% of the mass of the mixed solution, the mass of the thickener is 0.01% to 0.1% of the mass of the aqueous coating slurry, the mass of the dispersant is 0.5% to 1.5% of the mass of the mixed solution, the mass of the wetting agent is 0.01% to 1% of the mass of the aqueous coating slurry, and the mass of the tackifier is 0.01% to 0.05% of the mass of the aqueous coating slurry. The inorganic particles are one or both of alumina and boehmite with a particle size of 100nm~5μm; the adhesive is one or more of polyacrylate, modified polyacrylate and modified polyvinyl alcohol; the thickener is sodium carboxymethyl cellulose; the wetting agent is one or both of fatty alcohol polyoxyethylene ether and polyether modified organosilicon; and the adhesion promoter is a sulfate ester anionic surfactant.

4. The method for preparing a lithium battery separator according to claim 1, characterized in that, The molar ratio of triethylamine to sulfonated diamine is (1.1~2.5):1, and the molar ratio of sulfonated diamine to furanyl chloride is (1~2.5):

1.

5. The method for preparing a lithium battery separator according to claim 1, characterized in that, The mass ratio of the organic solvent to the sulfonated diamine is (3-11):

1.

6. The method for preparing a lithium battery separator according to claim 1, characterized in that, The inert gas is one or more of nitrogen, helium, and argon; the organic solvent is one or more of toluene, N,N-dimethylacetamide, N-methylpyrrolidone, N,N-dimethylformamide, dichloromethane, and dichloroethane; and the sulfonated diamine is one or more of 2,5-diaminobenzenesulfonic acid and 4,4'-diamino-3,3'-biphenyldisulfonic acid.

7. The method for preparing a lithium battery separator according to claim 1, characterized in that, The pH of the slurry after mixing with the alkali is 6-8, and the alkali includes at least one of lithium hydroxide, calcium hydroxide and sodium hydroxide.

8. A lithium battery separator, characterized in that, It is prepared by the method of any one of claims 1-7 for preparing lithium battery separator.

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