High performance ceramic composite separator and method of making and use thereof

Abstract

The application belongs to the technical field of battery materials, and particularly relates to a high-performance ceramic composite diaphragm as well as a preparation method and application thereof. The preparation method of the high-performance ceramic composite diaphragm comprises the following steps: mixing alumina powder with water, stirring and dispersing for 0.5-1 h, then adding carboxymethyl cellulose solution and a dispersing agent, stirring for 1-2 h, further adding acrylic acidified epoxy soybean oil polyol and a photoinitiator, and stirring for 0.5-1.5 h, so as to obtain ceramic slurry; uniformly coating the prepared ceramic slurry on a polyolefin diaphragm, and placing the coated diaphragm in an oven, and irradiating with a UV light for 2-5 min. The ceramic composite diaphragm prepared by using acrylic acidified epoxy soybean oil polyol as a binder not only can effectively improve the safety of a lithium ion battery by preventing short circuit under high temperature, but also has good infiltration and liquid absorption and retention capacity for electrolyte, so that the performance and service life of the battery can be greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of battery materials technology, specifically relating to a high-performance ceramic composite separator, its preparation method, and its application. Background Technology

[0002] Lithium-ion batteries have gained increasing attention due to their high energy density, high efficiency, and long cycle life. However, in recent years, the frequency of accidents involving digital devices and new energy vehicles using lithium-ion batteries has been rising, leading to serious safety issues and economic losses. Therefore, solving these accident problems is a key factor for the large-scale application of lithium-ion batteries. In lithium-ion batteries, one of the most important components related to battery safety is the separator, which prevents direct contact between the positive and negative electrodes and provides a viable lithium-ion channel during charging and discharging.

[0003] Over the past decade, polyolefin-based porous membranes, including polyethylene (PE) and polypropylene (PP), have been widely used as separators due to their good electrochemical stability, certain mechanical strength, and pore size. However, their low glass transition temperature and melting point cause them to shrink significantly at high temperatures. If the temperature is too high, membrane shrinkage can lead to internal short circuits. Once a short circuit occurs, the battery rapidly generates a large amount of heat, which further deteriorates the battery condition by melting the separator, potentially leading to combustion or even explosion. Furthermore, the incompatibility between polar organic solvents and non-polar polyolefin membranes results in poor electrolyte wettability, thus reducing ionic conductivity. The low porosity of polyolefin separators hinders electrolyte adsorption and retention, negatively impacting battery performance. Therefore, poor thermal stability and poor electrolyte compatibility significantly hinder the application of traditional polyolefin separators in next-generation batteries with high safety and superior performance.

[0004] To address these issues, many researchers have employed various methods to improve the thermal stability of separators. Among these, coating a PP or PE separator with a layer of inorganic ceramic particles is considered the most effective and economical method. In 2014, Zhao's research group developed a ceramic-coated separator (CCS) for lithium-ion batteries. This composite separator uses carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) as binders to bond and disperse the ceramic slurry. The SBR-CMC mixed binder has high adhesion and strong dispersibility, which is beneficial for the uniform dispersion of alumina. The composite separator based on this mixed binder can achieve a thermal shrinkage rate of 3.12% at temperatures below 135°C, while the thermal shrinkage rate of ordinary PE separators at the same temperature is 63.5% (Shi C, Zhang P, Chen L, et al. Effect of a thin ceramic-coating layer on thermal and electrochemical properties of polyethylene separator for lithium-ion batteries[J]. Journal of Power Sources, 2014, 270: 547-553.). In 2015, Lee's research group used polyimide (PI)-based polymer P84 as a binder between PP (polypropylene) separators and Al2O3 coatings. They verified the synergistic thermal stabilizing effect between the PI polymer binder and the ceramic coating by detecting the shrinkage behavior of the separator at high temperatures. Related experiments showed that the Al2O3 / PI-coated PP separator effectively prevented thermal shrinkage (10% at 150°C), compared to 33% in the control sample. This ceramic composite separator exhibited excellent thermal stability (Lee Y, Lee H, Lee T, et al. Synergistic thermal stabilization of ceramic / co-polyimide coated polypropylene separators for lithium-ion batteries[J]. Journal of Power Sources, 2015, 294: 537-544.).

[0005] Although the aforementioned adhesives for composite membranes can play a good role between polyolefin membranes and ceramic coatings, their raw materials are mainly derived from petroleum-based raw materials. Since petroleum resources are non-renewable, it is necessary to develop a composite membrane adhesive with high adhesion and strong dispersibility based on renewable raw materials. Summary of the Invention

[0006] To address the above problems, this invention provides a high-performance ceramic composite diaphragm, its preparation method, and its application.

[0007] According to a first aspect of the present invention, a method for preparing acrylated epoxidized soybean oil polyol is provided, comprising the following steps:

[0008] Mix epoxidized soybean oil, catalyst, and polymerization aid, heat to 60-100℃, add acrylic acid, then raise the temperature to 90-130℃ and react for 6-10 hours to obtain the final product.

[0009] In some embodiments, the catalyst is triphenylphosphine and the polymerization co-polymerizer is p-hydroxyanisole.

[0010] In some embodiments, the amount of epoxidized soybean oil is 5-15 parts by weight, the amount of catalyst is 0.06-0.18 parts, and the amount of polymerization aid is 0.01-0.03 parts; the amount of acrylic acid added is based on a molar ratio of 1:1.2-1.6 between the epoxy groups in the epoxidized soybean oil and the carboxyl groups in the acrylic acid.

[0011] In some embodiments, the reaction product is further washed by adding cyclohexane and water until the pH of the aqueous layer is neutral. After washing, the cyclohexane is recovered by atmospheric distillation, and small molecules are removed by vacuum distillation. The small molecules referred to here are mainly water molecules.

[0012] In some embodiments, the preparation method of epoxidized soybean oil includes the following steps:

[0013] Using soybean oil as raw material, add organic acid oxidant and the first batch of hydrogen peroxide, heat to 40-60℃ and stir for 30 minutes, then add strong acid catalyst and continue stirring for 0.5-1.5 hours. When the solution color changes from yellow to red, add the second batch of hydrogen peroxide and continue the reaction for 6-10 hours to obtain the final product.

[0014] In some embodiments, the organic acid oxidant is formic acid or acetic acid, and the strong acid catalyst is concentrated sulfuric acid with a concentration of 80-95 wt%.

[0015] In some embodiments, by weight, the amount of soybean oil used is 230-270g, the amount of organic acid oxidant is 16-20g, the amount of the first batch of hydrogen peroxide is 40-60ml, the amount of strong acid catalyst is 2-5 drops, and the amount of the second batch of hydrogen peroxide is 40-60ml.

[0016] In some embodiments, the reaction product is also washed, during which hexane and water are added, and the washing continues until the pH of the aqueous layer is neutral. After washing, hexane is recovered by atmospheric distillation, and small molecules are removed by vacuum distillation. The small molecules referred to here are mainly water molecules.

[0017] According to a second aspect of the present invention, an acrylic epoxidized soybean oil polyol prepared by the above-described preparation method is provided.

[0018] According to a third aspect of the present invention, the above-described acrylic epoxidized soybean oil polyol is provided as a battery binder.

[0019] According to a fourth aspect of the present invention, a method for preparing a high-performance ceramic composite separator is provided, comprising the following steps:

[0020] Mix alumina powder with water and stir to disperse for 0.5-1 h. Then add carboxymethyl cellulose solution and dispersant and stir for 1-2 h. Finally, add acrylic epoxidized soybean oil polyol and photoinitiator and stir for 0.5-1.5 h to obtain ceramic slurry.

[0021] The prepared ceramic slurry is uniformly coated onto a polyolefin separator. The coated separator is then placed in an oven at 40-80℃ and irradiated with ultraviolet light to obtain a high-performance ceramic composite separator.

[0022] In some embodiments, by weight, the amount of alumina powder is 120-180 parts, the amount of water is 170-230 parts, the amount of carboxymethyl cellulose solution is 40-60 parts, the amount of dispersant is 0.8-1.2 parts, the amount of acrylic epoxidized soybean oil polyol is 3.8-4.2 parts, and the amount of photoinitiator is 0.1-0.2 parts.

[0023] In some embodiments, the concentration of carboxymethyl cellulose in the carboxymethyl cellulose solution is 4-8 wt%.

[0024] In some embodiments, the dispersant is at least one selected from polyacrylic acid, polyacrylate, polyacrylamide, and styrene-maleic anhydride copolymer. Specifically, the polyacrylate may be potassium polyacrylate and / or sodium polyacrylate.

[0025] In some embodiments, the photoinitiator is photoinitiator 1173.

[0026] In some embodiments, the coating thickness of the ceramic slurry is 2.4-2.6 μm.

[0027] In some embodiments, the polyolefin membrane is a polyethylene membrane or a polypropylene membrane.

[0028] In some implementations, the ultraviolet lamp has a power of 300-500W, a radiation distance of 10-20cm, and an irradiation time of 2-5min.

[0029] According to a fifth aspect of the present invention, a high-performance ceramic composite diaphragm prepared by the above-described preparation method is provided.

[0030] According to a sixth aspect of the present invention, a lithium-ion battery is provided, comprising the above-described high-performance ceramic composite separator.

[0031] In some embodiments, a lithium-ion battery positive electrode, a lithium metal negative electrode, a high-performance ceramic composite separator, and an electrolyte are assembled into a 2032 type button half-cell in an argon glove box with a water content of less than 10 ppm; wherein the electrolyte is a 1 mol / L lithium hexafluorophosphate (LiPF6) solution, and the solvent of the solution is a mixture of ethylene carbonate (EC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC) in a volume ratio of 1:1:1.

[0032] Compared with the prior art, the beneficial effects of the present invention include:

[0033] (1) The acrylic epoxy soybean oil polyol prepared in this invention is an aqueous binder suitable for bonding between ceramic coating (Al2O3 coating) and polyolefin membrane. The binder prepared in this invention enhances the thermal stability and mechanical properties of the membrane by strengthening the synergistic effect between the ceramic coating and the polyolefin membrane.

[0034] (2) The high-performance ceramic composite separator prepared by the present invention using acrylic epoxidized soybean oil polyol as a binder improves thermal stability. The ceramic composite separator can effectively improve the safety of lithium-ion batteries by preventing short circuits at high temperatures. On the other hand, the ceramic composite separator has good wetting and liquid absorption and retention capabilities for electrolytes, which greatly improves the performance and service life of the battery.

[0035] (3) The water-based binder prepared by the present invention, acrylic epoxidized soybean oil polyol, has a wide range of raw material sources, low price, and is renewable. Attached Figure Description

[0036] Figure 1 These are thermal shrinkage test diagrams of the diaphragms in Examples 1-3 and Comparative Examples 1-2 of the present invention.

[0037] Figure 2 These are peel strength test diagrams of the diaphragms in Examples 1-3 and Comparative Example 1 of the present invention. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. The materials involved in the following embodiments are all commercially available.

[0039] The electrolyte used in the following examples and comparative examples is a 1 mol / L lithium hexafluorophosphate (LiPF6) solution, and the solvent of the solution is a mixture of ethylene carbonate (EC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC) in a volume ratio of 1:1:1.

[0040] Example 1

[0041] The method for preparing the battery containing a high-performance ceramic composite separator in this embodiment includes the following steps:

[0042] (1) Preparation of water-based binder: 250g soybean oil, 18g formic acid, and 50ml hydrogen peroxide were added sequentially to a three-necked flask. The mixture was stirred at 50℃ for 30 minutes, then 4 drops of 90wt% concentrated sulfuric acid were added, and stirring continued for 1 hour. When the solution color changed from yellow to red, another 50ml of hydrogen peroxide was added, and the reaction continued for 8 hours. After the reaction was complete, the resulting solution was poured into a separatory funnel, and hexane was added and mixed with water. The mixture was then washed to remove the aqueous layer. This process was repeated until the pH of the aqueous layer was neutral. After washing, hexane was recovered by atmospheric distillation, and small molecules were removed by vacuum distillation to obtain epoxidized soybean oil.

[0043] Add 10g of epoxidized soybean oil to another three-necked flask, then add 0.12g of triphenylphosphine and 0.02g of p-hydroxyanisole. Heat to 80℃, then add acrylic acid at a molar ratio of 1:1.4 (epoxy groups in epoxidized soybean oil to carboxyl groups in acrylic acid). The temperature is then raised to 110℃, and the reaction is allowed to proceed for 7 hours. After the reaction, pour the resulting solution into another separatory funnel, add cyclohexane, mix and shake, wash with water to remove the aqueous layer, and repeat the process until the pH of the aqueous layer is neutral. After washing, recover the cyclohexane by atmospheric distillation and remove small molecules by vacuum distillation to obtain the acrylic acidified epoxidized soybean oil polyol.

[0044] (2) Preparation of high-performance ceramic composite membrane: 150g of alumina powder and 200g of water are added to a dispersion tank and stirred in a disperser for 1h. Then, 50.00g of 5wt% carboxymethyl cellulose solution and 1.00g of dispersant styrene-maleic anhydride copolymer are added and stirred for 1.5h. Then, 4.05g of acrylic epoxidized soybean oil polyol obtained in step (1) and 0.1215g of photoinitiator 1173 are added and stirred for 1h to obtain ceramic slurry.

[0045] The prepared ceramic slurry was uniformly coated onto the polypropylene diaphragm using a microgravure coating machine to a thickness of 2.5 μm. The coated diaphragm was then placed in an oven at 45°C and irradiated with a 400W ultraviolet lamp (15cm distance) for 3 minutes to obtain a high-performance ceramic composite diaphragm.

[0046] (3) Assembly of button cells: LiNi0.8 Co 0.1 Mn 0.1 The positive electrode, lithium metal negative electrode, high-performance ceramic composite membrane prepared in step (2) and electrolyte are assembled into a 2032 button half cell in an argon glove box with a water content of less than 10 ppm.

[0047] Example 2

[0048] The method for preparing the battery containing a high-performance ceramic composite separator in this embodiment includes the following steps:

[0049] (1) Preparation of water-based binder: 250g soybean oil, 18g formic acid, and 50ml hydrogen peroxide were added sequentially to a three-necked flask. The mixture was stirred at 50℃ for 30 minutes, then 3 drops of 90wt% concentrated sulfuric acid were added, and stirring continued for 1 hour. When the solution color changed from yellow to red, another 50ml of hydrogen peroxide was added, and the reaction continued for 8 hours. After the reaction was complete, the resulting solution was poured into a separatory funnel, and hexane was added and mixed with water. The mixture was then washed with water to remove the aqueous layer. This process was repeated until the pH of the aqueous layer was neutral. After washing, hexane was recovered by atmospheric distillation, and small molecules were removed by vacuum distillation to obtain epoxidized soybean oil.

[0050] Add 10g of epoxidized soybean oil to another three-necked flask, then add 0.12g of triphenylphosphine and 0.02g of p-hydroxyanisole. Heat to 80℃, then add acrylic acid at a molar ratio of 1:1.2 (epoxy groups in epoxidized soybean oil to carboxyl groups in acrylic acid). The temperature is then raised to 90℃, and the reaction is allowed to proceed for 7 hours. After the reaction, pour the resulting solution into another separatory funnel, add cyclohexane, mix and shake, wash with water to remove the aqueous layer, and repeat the process until the pH of the aqueous layer is neutral. After washing, recover the cyclohexane by atmospheric distillation and remove small molecules by vacuum distillation to obtain the acrylic acidified epoxidized soybean oil polyol.

[0051] (2) Preparation of high-performance ceramic composite membrane: 150g of alumina powder and 200g of water are added to a dispersion tank and stirred in a disperser for 1h. Then, 50.00g of 5wt% carboxymethyl cellulose solution and 1.00g of dispersant styrene-maleic anhydride copolymer are added and stirred for 1.5h. Then, 4.05g of acrylic epoxidized soybean oil polyol obtained in step (1) and 0.1215g of photoinitiator 1173 are added and stirred for 1h to obtain ceramic slurry.

[0052] The prepared ceramic slurry was uniformly coated onto the polypropylene diaphragm using a microgravure coating machine to a thickness of 2.5 μm. The coated diaphragm was then placed in an oven at 45°C and irradiated with a 400W ultraviolet lamp (15cm distance) for 3 minutes to obtain a high-performance ceramic composite diaphragm.

[0053] (3) Assembly of button cells: LiNi 0.8 Co 0.1 Mn 0.1 The positive electrode, lithium metal negative electrode, high-performance ceramic composite membrane prepared in step (2) and electrolyte are assembled into a 2032 button half cell in an argon glove box with a water content of less than 10 ppm.

[0054] Example 3

[0055] The method for preparing the battery containing a high-performance ceramic composite separator in this embodiment includes the following steps:

[0056] (1) Preparation of water-based binder: 250g soybean oil, 18g formic acid, and 50ml hydrogen peroxide were added sequentially to a three-necked flask. The mixture was stirred at 50℃ for 30 minutes, then 4 drops of 90wt% concentrated sulfuric acid were added, and stirring continued for 1 hour. When the solution color changed from yellow to red, another 50ml of hydrogen peroxide was added, and the reaction continued for 8 hours. After the reaction was complete, the resulting solution was poured into a separatory funnel, and hexane was added and mixed with water. The mixture was then washed to remove the aqueous layer. This process was repeated until the pH of the aqueous layer was neutral. After washing, hexane was recovered by atmospheric distillation, and small molecules were removed by vacuum distillation to obtain epoxidized soybean oil.

[0057] Add 10g of epoxidized soybean oil to another three-necked flask, then add 0.12g of triphenylphosphine and 0.02g of p-hydroxyanisole. Heat to 80℃, then add acrylic acid at a molar ratio of 1:1.6 (epoxy groups in epoxidized soybean oil to carboxyl groups in acrylic acid). The temperature is then raised to 130℃, and the reaction is allowed to proceed for 7 hours. After the reaction, pour the resulting solution into another separatory funnel, add cyclohexane, mix and shake, wash with water to remove the aqueous layer, and repeat the process until the pH of the aqueous layer is neutral. After washing, recover the cyclohexane by atmospheric distillation and remove small molecules by vacuum distillation to obtain the acrylic acidified epoxidized soybean oil polyol.

[0058] (2) Preparation of high-performance ceramic composite membrane: 150g of alumina powder and 200g of water are added to a dispersion tank and stirred in a disperser for 1h. Then, 50.00g of 5wt% carboxymethyl cellulose solution and 1.00g of dispersant styrene-maleic anhydride copolymer are added and stirred for 1.5h. Then, 4.05g of acrylic epoxidized soybean oil polyol obtained in step (1) and 0.1215g of photoinitiator 1173 are added and stirred for 1h to obtain ceramic slurry.

[0059] The prepared ceramic slurry was uniformly coated onto the polypropylene diaphragm using a microgravure coating machine to a thickness of 2.5 μm. The coated diaphragm was then placed in an oven at 45°C and irradiated with a 400W ultraviolet lamp (15cm distance) for 3 minutes to obtain a high-performance ceramic composite diaphragm.

[0060] (3) Assembly of button cells: LiNi 0.8 Co 0.1 Mn 0.1 The positive electrode, lithium metal negative electrode, high-performance ceramic composite membrane prepared in step (2) and electrolyte are assembled into a 2032 button half cell in an argon glove box with a water content of less than 10 ppm.

[0061] Comparative Example 1

[0062] The method for preparing the battery in this comparative example includes the following steps:

[0063] (1) Preparation of ceramic composite membrane: 150g of alumina powder and 200g of water were added to a dispersion tank and stirred in a disperser for 1h. Then, 50.00g of 5wt% carboxymethyl cellulose solution and 1.00g of dispersant styrene-maleic anhydride copolymer were added and stirred for 1.5h. Then, 4.05g of commercial polyvinylidene fluoride (PVDF) binder was added and stirred for 1h to obtain ceramic slurry.

[0064] The prepared ceramic slurry was uniformly coated onto the polypropylene diaphragm using a microgravure coating machine to a thickness of 2.5 μm. The coated diaphragm was then placed in an oven at 45°C to dry and remove moisture, thus obtaining the ceramic composite diaphragm.

[0065] (2) Assembly of button cells: LiNi 0.8 Co 0.1 Mn 0.1 The positive electrode, lithium metal negative electrode, ceramic composite separator prepared in step (1) and electrolyte are assembled into a 2032 type button half cell in an argon glove box with a water content of less than 10 ppm.

[0066] Comparative Example 2

[0067] The method for preparing the battery in this comparative example includes the following steps:

[0068] LiNi 0.8 Co 0.1 Mn 0.1 The positive electrode, lithium metal negative electrode, commercial polypropylene membrane (Celgard 2500 membrane), and electrolyte were assembled into a 2032 type button half cell in an argon glove box with a water content of less than 10 ppm.

[0069] To verify the thermal stability of the high-performance ceramic composite membrane of the present invention, the ceramic composite membranes prepared in Examples 1-3, Comparative Example 1, and the commercial Celgard 2500 membrane of Comparative Example 2 were cut into 12cm × 12cm pieces. Crosshairs were lightly drawn on the membranes, and they were placed in a forced-air drying oven and heated to 150°C for 30 minutes. The thermal shrinkage of the membranes was observed, and the test results are shown in Table 1 and Table 2. Figure 1 As shown.

[0070] Table 1 Thermal shrinkage rate of the diaphragm

[0071]

[0072] As shown in Table 1, the original polypropylene diaphragm without ceramic coating in Comparative Example 2 exhibited a heat shrinkage rate of 87% at 150°C, while the heat shrinkage rates of the diaphragms with ceramic coating (Al2O3 coating) in Examples 1-3 and Comparative Example 1 were generally lower. Furthermore, compared to the 8% heat shrinkage rate of Comparative Example 1, the heat shrinkage rates of Examples 1-3 were even lower, with Example 1 showing a heat shrinkage rate of only 2%. Compared to Comparative Example 1, the ceramic composite diaphragms of Examples 1-3 used acrylic epoxidized soybean oil polyol as an aqueous binder instead of commercial polyvinylidene fluoride binder, indicating that the ceramic composite diaphragm prepared by this invention, using acrylic epoxidized soybean oil polyol as an aqueous binder, can enhance the interaction force between the diaphragm and the ceramic coating, thereby effectively suppressing the heat shrinkage of the diaphragm.

[0073] In addition, in order to verify the mechanical properties of the high-performance ceramic composite diaphragm of the present invention, the peel strength of the ceramic composite diaphragms of Examples 1-3 and Comparative Example 1 was tested.

[0074] Test method: The test shall be conducted in accordance with GB / T 2792-2014 "Test method for peel strength of adhesive tape". The diaphragm shall be cut into samples 24 mm wide and 300 mm long for later use. 20 mm wide and 60 mm long 3M double-sided tape shall be adhered to a steel plate (125 mm long, 50 mm wide, 1.1 mm thick). The coated side of the cut diaphragm shall be adhered to the steel plate. One end of the stainless steel plate shall be fixed to the lower clamp of the tensile testing machine. The upper clamp of the testing machine shall clamp the free end of the diaphragm at a 180° angle to the stainless steel plate. Tension shall be applied at a specified rate (200 mm / min). Each group shall contain no fewer than 3 samples.

[0075] Test results are as follows Figure 2 As shown.

[0076] from Figure 2 As can be seen, the peel strength of the ceramic composite membranes in Examples 1-3 is higher than that in Comparative Example 1. Specifically, the peel strength of Example 1 reaches 124 N / m, while the peel strength of Comparative Example 1 is only 93 N / m, representing a 33.3% increase in peel strength compared to Comparative Example 1. It is precisely because of the strong adhesive effect of the acrylic epoxidized soybean oil polyol binder that the ceramic coating and the membrane substrate can be perfectly bonded together, thus giving the ceramic composite membrane of this invention its high peel strength.

[0077] In summary, the ceramic composite separator prepared by this invention, using acrylated epoxidized soybean oil polyol as a binder, exhibits excellent performance. The ceramic coating provides high heat resistance, while the binder provides high adhesion to maintain the structural integrity of the ceramic coating and the entire composite separator. On one hand, due to improved thermal stability, the ceramic composite separator can effectively enhance the safety of lithium-ion batteries by preventing short circuits at high temperatures. On the other hand, the Al2O3 oxide in the ceramic coating of the ceramic composite separator has a good affinity for polar solvents in the electrolyte. Furthermore, the particle size of the Al2O3 particles in the ceramic coating is typically between 400-500 nm, and its microporous structure provides additional space for electrolyte absorption. Therefore, the ceramic composite separator possesses excellent wetting and electrolyte absorption and retention capabilities, which can significantly improve battery performance and lifespan.

[0078] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for producing a high-performance ceramic composite separator, characterized by, It comprises the following steps: Mixing the alumina powder with water, stirring and dispersing for 0.5-1 h, then adding the carboxymethyl cellulose solution, stirring for 1-2 h, and then adding the acrylic acidized epoxy soybean oil polyol and the photoinitiator, stirring for 0.5-1.5 h, to obtain the ceramic slurry; Coating the prepared ceramic slurry on the polyolefin separator uniformly, placing the coated separator in an oven at 40-80℃, and irradiating with a UV light lamp, to obtain the high-performance ceramic composite separator; The acrylic acidized epoxy soybean oil polyol is prepared by the following method: mixing the epoxy soybean oil, the catalyst, and the polymerization promoter, heating to 60-100℃, then adding the acrylic acid, and then heating to 90-130℃, and reacting for 6-10 h, to obtain the product; the catalyst is triphenylphosphine, and the polymerization promoter is p-hydroxyanisole.

2. The method of claim 1, wherein the high performance ceramic composite separator is prepared by the steps of: The amount of the epoxy soybean oil is 5-15 parts by mass, the amount of the catalyst is 0.06-0.18 parts by mass, and the amount of the polymerization promoter is 0.01-0.03 parts by mass. The acrylic acid is added in a molar ratio of 1:1.2-1.6 between the epoxy groups in the epoxy soybean oil and the carboxyl groups in the acrylic acid.

3. The method of claim 1 or 2, wherein the high performance ceramic composite separator is prepared by the steps of: When preparing the acrylic acidized epoxy soybean oil polyol, a step of washing the reaction product is further included, and cyclohexane and water need to be added during the washing process, the washing is continued until the pH value of the water layer is neutral, and then the cyclohexane is recovered by normal pressure distillation and the small molecules are removed by reduced pressure distillation after the washing is completed.

4. The method of claim 1 or 2, wherein the high performance ceramic composite separator is prepared by the steps of: The amount of the alumina powder is 120-180 parts by mass, the amount of the water is 170-230 parts by mass, the amount of the carboxymethyl cellulose solution is 40-60 parts by mass, the amount of the dispersant is 0.8-1.2 parts by mass, the amount of the acrylic acidized epoxy soybean oil polyol is 3.8-4.2 parts by mass, and the amount of the photoinitiator is 0.1-0.2 parts by mass.

5. The method of claim 1 or 2, wherein the high performance ceramic composite separator is prepared by the steps of: The concentration of the carboxymethyl cellulose in the carboxymethyl cellulose solution is 4-8 wt%; The dispersant is at least one of polyacrylic acid, polyacrylic acid salt, polyacrylamide, and styrene-maleic anhydride copolymer; The photoinitiator is photoinitiator 1173; The coating thickness of the ceramic slurry is 2.4-2.6 μm; The polyolefin separator is a polyethylene separator or a polypropylene separator; The power of the UV light lamp is 300-500 W, the irradiation distance is 10-20 cm, and the irradiation time is 2-5 min.

6. The high-performance ceramic composite separator prepared by the preparation method according to any one of claims 1-5.

7. A lithium-ion battery, characterized by It comprises the high-performance ceramic composite separator according to claim 6.

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