Preparation method of water-based primer adhesive for lithium battery foil

Abstract

The application provides a preparation method of water-based primer adhesive for lithium battery foils and relates to the technical field of lithium ion batteries. The composite conductive material, modified water-based acrylic resin and dispersant are added into a first solvent, and the mixture is stirred at a rotating speed of 800-1200 r / min for 4-6 h in an environment at 35-45 DEG C to prepare the water-based primer adhesive. The preparation method provided by the application realizes the target of forming an efficient coating on the surface of the lithium battery foil through ingenious formula design. The composite conductive material and the modified water-based acrylic resin jointly form a conductive network on the surface of the foil, which not only effectively reduces the contact resistance between the active material and the foil, but also significantly improves the overall conductive performance of the foil, thereby providing a strong guarantee for the efficient operation of the lithium battery.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a method for preparing an aqueous primer for lithium battery foil. Background Technology

[0002] Aluminum foil plays a crucial role as the positive electrode current collector in lithium batteries. It not only carries the active material but also collects electrons generated by the active material and directs them to the external circuit to form an electric current. Therefore, the electrochemical behavior of the aluminum foil directly affects battery performance. Traditionally, the surface of the aluminum foil has been modified by acid and alkali etching to reduce its surface tension; however, this method is difficult to control precisely and achieves a uniform surface morphology.

[0003] In contrast, surface treatment of the positive electrode current collector using functional coatings is a more effective method. By uniformly coating a conductive material onto the aluminum foil surface, not only can the liquid absorption capacity of the positive electrode be improved, and the adhesion between the active material and the current collector enhanced, but the ability of the positive electrode to collect microcurrents from the active material can also be improved, contact resistance reduced, and polarization decreased, thereby improving battery consistency and rate performance. Furthermore, the functional coating can protect the aluminum foil and slow down corrosion. However, existing functional coatings are susceptible to corrosion by electrolytes, and the heat generated during battery operation may cause the aluminum foil to oxidize, leading to the detachment of the coating, affecting the normal operation of the lithium battery, and even posing safety hazards. Simultaneously, to ensure the active material adheres firmly to the smooth metal current collector surface, a large amount of insulating binder is usually required, which reduces the conductivity and energy density of the electrode.

[0004] Therefore, providing a water-based primer with good conductivity for lithium battery foil is an important problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing an aqueous primer for lithium battery foil. To achieve the above objective, this invention adopts the following technical solution:

[0006] A method for preparing an aqueous primer for lithium battery foil, the method comprising the following steps:

[0007] The composite conductive material, modified waterborne acrylic resin and dispersant are added to the first solvent and stirred and mixed at 800-1200 r / min for 4-6 h at 35-45℃ to obtain the waterborne primer.

[0008] The preparation method of the composite conductive material includes the following steps:

[0009] Hydroxylated multi-walled carbon nanotubes and diethoxy(3-glycidyloxypropyl)methylsilane were mixed and heated to 60–65 °C to obtain epoxy-based carbon nanotubes. Under an inert gas atmosphere, the epoxy-based carbon nanotubes and 1-aminopyrrole were mixed and heated to 60–70 °C to obtain pyrrole-containing ring-based carbon nanotubes. The composite conductive material was prepared by stirring and polymerizing the pyrrole-containing ring-based carbon nanotubes, pyrrole monomers, and anhydrous ferric chloride.

[0010] The preparation method of the modified waterborne acrylic resin includes the following steps:

[0011] After mixing cis-2-butene-1,4-diol and thionyl chloride at 0–5 °C, levodopa was added and the mixture was stirred at 80–90 °C to obtain an intermediate product. The intermediate product, 1H,1H,2H,2H-heptadecyl acrylate, methyl methacrylate, acrylic acid, and butyl acrylate were mixed to obtain a mixture. Under an inert gas atmosphere, the mixture was mixed with benzoyl peroxide at 100–110 °C to prepare the modified waterborne acrylic resin.

[0012] Furthermore, the weight ratio of the hydroxylated multi-walled carbon nanotubes to diethoxy(3-glycidoxypropyl)methylsilane is 1:6 to 8.

[0013] Furthermore, the weight ratio of the epoxy-based carbon nanotubes to 1-aminopyrrole is 1:3 to 5.

[0014] Furthermore, the weight ratio of the pyrrole-containing carbon nanotubes, pyrrole monomers, and anhydrous ferric chloride is 1:0.5-2.5:0.3-0.8.

[0015] Further, the weight ratio of cis-2-butene-1,4-diol, thionyl chloride and levodopa is 1:0.5-0.6:0.4-0.6.

[0016] Furthermore, the weight ratio of the intermediate product, 1H,1H,2H,2H-heptadecyl acrylate, methyl methacrylate, acrylic acid, and butyl acrylate is 1–2:0.2–0.3:1–1.5:0.8–1.2:1.5–2.

[0017] Further, the weight ratio of the mixture to benzoyl peroxide is 10-20:0.2-0.3.

[0018] Furthermore, the inert gas is nitrogen or argon.

[0019] Furthermore, the weight ratio of the composite conductive material, modified waterborne acrylic resin, dispersant and first solvent is 10-20:20-30:2-4:30-50.

[0020] Further, the dispersant is polyvinylpyrrolidone, polyacrylic acid, or 2-hydroxyphosphonoacetic acid.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) This invention first utilizes an epoxy-based silane coupling agent to react with carbon nanotubes to obtain epoxy-based carbon nanotubes. Subsequently, the epoxy groups in the epoxy-based carbon nanotubes react with the amino groups in 1-aminopyrrole to obtain pyrrole-containing carbon nanotubes. Based on this, the pyrrole rings in the pyrrole-containing carbon nanotubes undergo a further polymerization reaction with pyrrole monomers to form polypyrrole, which then encapsulates the carbon nanotubes, thereby obtaining a composite conductive material. This composite conductive material exhibits a core-shell structure, in which the carbon nanotubes, as the core, possess excellent conductivity. The polypyrrole, as the outer shell, not only effectively improves the dispersibility of the carbon nanotubes and reduces agglomeration, allowing them to adhere uniformly to the surface of the lithium battery foil, but also, as a highly conductive polymer, polypyrrole, after encapsulating the carbon nanotubes, not only does not reduce its original conductivity but also plays a synergistic role, further enhancing the overall conductivity of the composite conductive material, thereby helping to improve the conductivity of the lithium battery foil.

[0023] (2) In this invention, levodopa is grafted onto cis-2-buten-1,4-diol via esterification to obtain an intermediate product, which is then polymerized to obtain a modified waterborne acrylic resin. The catechol structure in levodopa not only enhances the adhesion between the modified waterborne acrylic resin and the lithium battery foil, but also improves the adhesion and durability of the waterborne primer. In addition, the modified waterborne acrylic resin is rich in CF bonds on its side chains, which endows the waterborne primer with good chemical resistance and high temperature resistance, effectively preventing the lithium battery foil from being corroded by the electrolyte, thus providing effective protection for the lithium battery foil.

[0024] (3) The water-based primer for lithium battery foil involved in this invention achieves the goal of forming a high-efficiency coating on the surface of lithium battery foil through ingenious formulation design. This water-based primer is prepared by mixing and stirring a composite conductive material, a modified water-based acrylic resin, a dispersant, and a first solvent. After being coated onto the lithium battery foil and dried, the resulting coating significantly enhances the various properties of the foil. The composite conductive material and the modified water-based acrylic resin work together on the foil surface to form a conductive network, which not only effectively reduces the contact resistance between the active material and the foil but also significantly improves the overall conductivity of the foil, providing a strong guarantee for the efficient operation of the lithium battery. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0027] Hydroxylated multi-walled carbon nanotubes were purchased from the Carbon Nanotube Development Center of the Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences.

[0028] Preparation Example 1:

[0029] The preparation of composite conductive materials includes the following steps:

[0030] Five parts by weight of hydroxylated multi-walled carbon nanotubes were dispersed in 500 parts by weight of toluene by sonication at 100 W for 10 min. The mixture was heated to 60 °C and 30 parts by weight of diethoxy(3-glycidyloxypropyl)methylsilane were added. The mixture was stirred under reflux at 300 r / min for 10 h, filtered through an organic filter membrane, washed three times with water and acetone, and vacuum dried at 60 °C for 12 h to obtain epoxy-based carbon nanotubes. Ten parts by weight of epoxy-based carbon nanotubes and 30 parts by weight of 1-aminopyrrole were dispersed in 500 parts by weight of methanol by sonication at 100 W for 10 min. The mixture was stirred at 600 r / min for 2 h under nitrogen protection at 60 °C, washed, and dried to obtain pyrrole-containing carbon nanotubes. Ten parts by weight of pyrrole-containing carbon nanotubes and 3 parts by weight of anhydrous ferric chloride were dispersed in 500 parts by weight of a second solvent (V 去离子水 and V 甲醇 In a mixture of 4:1, 5 parts by weight of pyrrole monomer were added and stirred at 500 r / min for 25 h at 23 °C. The mixture was then washed three times with deionized water and ethanol and dried at 60 °C for 24 h to obtain the composite conductive material.

[0031] Preparation Example 2:

[0032] The preparation of composite conductive materials includes the following steps:

[0033] Five parts by weight of hydroxylated multi-walled carbon nanotubes were dispersed in 500 parts by weight of toluene by sonication at 120 W for 15 min. The mixture was heated to 61 °C and 33 parts by weight of diethoxy(3-glycidoxypropyl)methylsilane were added. The mixture was stirred under reflux at 350 r / min for 11 h, filtered through an organic filter membrane, washed three times with water and acetone, and vacuum dried at 60 °C for 12 h to obtain epoxy-based carbon nanotubes. Ten parts by weight of epoxy-based carbon nanotubes and 35 parts by weight of 1-aminopyrrole were dispersed in 500 parts by weight of methanol by sonication at 130 W for 15 min. The mixture was stirred at 700 r / min for 2.4 h under argon protection at 62 °C, washed, and dried to obtain pyrrole-containing carbon nanotubes. Ten parts by weight of pyrrole-containing carbon nanotubes and 5 parts by weight of anhydrous ferric chloride were dispersed in 500 parts by weight of a second solvent (V) by sonication at 120 W for 18 min. 去离子水 and V 甲醇 In a mixture of 4:1, 10 parts by weight of pyrrole monomer were added and stirred at 600 r / min for 27 h at 24 °C. The mixture was then washed three times with deionized water and ethanol and dried at 60 °C for 24 h to obtain the composite conductive material.

[0034] Preparation Example 3:

[0035] The preparation of composite conductive materials includes the following steps:

[0036] Five parts by weight of hydroxylated multi-walled carbon nanotubes were dispersed in 500 parts by weight of toluene by sonication at 160 W for 20 min. The mixture was heated to 63 °C and 35 parts by weight of diethoxy(3-glycidoxypropyl)methylsilane were added. The mixture was stirred under reflux at 450 r / min for 11 h, filtered through an organic filter membrane, washed three times with water and acetone, and vacuum dried at 60 °C for 12 h to obtain epoxy-based carbon nanotubes. Ten parts by weight of epoxy-based carbon nanotubes and 45 parts by weight of 1-aminopyrrole were dispersed in 500 parts by weight of methanol by sonication at 180 W for 25 min. The mixture was stirred at 800 r / min for 2.7 h under argon protection at 68 °C, washed, and dried to obtain pyrrole-containing carbon nanotubes. Ten parts by weight of pyrrole-containing carbon nanotubes and 7 parts by weight of anhydrous ferric chloride were dispersed in 500 parts by weight of a second solvent (V 去离子水 and V 甲醇 In a mixture of 4:1, 20 parts by weight of pyrrole monomer were added and stirred at 800 r / min for 28 h at 24 °C. The mixture was then washed three times with deionized water and ethanol and dried at 60 °C for 24 h to obtain the composite conductive material.

[0037] Preparation Example 4:

[0038] The preparation of composite conductive materials includes the following steps:

[0039] Five parts by weight of hydroxylated multi-walled carbon nanotubes were dispersed in 500 parts by weight of toluene by sonication at 200 W for 30 min. The mixture was heated to 65 °C and 40 parts by weight of diethoxy(3-glycidoxypropyl)methylsilane were added. The mixture was stirred under reflux at 500 r / min for 12 h, filtered through an organic filter membrane, washed three times with water and acetone, and vacuum dried at 60 °C for 12 h to obtain epoxy-based carbon nanotubes. Ten parts by weight of epoxy-based carbon nanotubes and 50 parts by weight of 1-aminopyrrole were dispersed in 500 parts by weight of methanol by sonication at 200 W for 30 min. The mixture was stirred at 900 r / min for 3 h under nitrogen protection at 70 °C, washed, and dried to obtain pyrrole-containing carbon nanotubes. Ten parts by weight of pyrrole-containing carbon nanotubes and 8 parts by weight of anhydrous ferric chloride were dispersed in 500 parts by weight of a second solvent (V 去离子水 and V 甲醇 In a mixture of 4:1, 25 parts by weight of pyrrole monomer were added and polymerized at 1000 r / min in an environment of 25°C for 30 h. The mixture was then washed three times with deionized water and ethanol and dried in an environment of 60°C for 24 h to obtain a composite conductive material.

[0040] Preparation Example 5:

[0041] The preparation of modified waterborne acrylic resin includes the following steps:

[0042] Five parts by weight of thionyl chloride were added to 10 parts by weight of cis-2-buten-1,4-diol. The mixture was stirred at 500 r / min for 0.5 h at 0 °C, and then four parts by weight of levodopa were added. The mixture was stirred and heated to 80 °C and refluxed for 6 h to obtain an intermediate product. Ten parts by weight of the intermediate product, two parts by weight of 1H,1H,2H,2H-heptadecyl acrylate, ten parts by weight of methyl methacrylate, eight parts by weight of acrylic acid, and 15 parts by weight of butyl acrylate were stirred and mixed at 200 r / min for 15 min to obtain a mixture. Under nitrogen protection, ten parts by weight of the above mixture and 0.2 parts by weight of benzoyl peroxide were dispersed in 100 parts by weight of n-butanol. The mixture was heated to 100 °C and refluxed for 6 h to obtain a modified waterborne acrylic resin.

[0043] Preparation Example 6:

[0044] The preparation of modified waterborne acrylic resin includes the following steps:

[0045] 5.3 parts by weight of thionyl chloride were added to 10 parts by weight of cis-2-buten-1,4-diol, and stirred at 550 r / min for 0.8 h at 2 °C. Then, 5 parts by weight of levodopa were added and stirred until the mixture was heated to 83 °C and refluxed for 6.5 h to obtain an intermediate product. 12 parts by weight of the intermediate product, 2.3 parts by weight of 1H,1H,2H,2H-heptadecyl acrylate, 11 parts by weight of methyl methacrylate, 10 parts by weight of acrylic acid, and 18 parts by weight of butyl acrylate were stirred and mixed at 230 r / min for 20 min to obtain a mixture. Under argon protection, 13 parts by weight of the above mixture and 0.23 parts by weight of benzoyl peroxide were dispersed in 100 parts by weight of n-butanol, and the mixture was heated to 105 °C and refluxed for 7 h to obtain a modified waterborne acrylic resin.

[0046] Preparation Example 7:

[0047] The preparation of modified waterborne acrylic resin includes the following steps:

[0048] 5.8 parts by weight of thionyl chloride were added to 10 parts by weight of cis-2-buten-1,4-diol, and stirred at 600 r / min for 0.8 h at 3 °C. Then, 5.5 parts by weight of levodopa were added, and the mixture was stirred and heated to 87 °C and refluxed for 7.5 h to obtain an intermediate product. 18 parts by weight of the intermediate product, 2.8 parts by weight of 1H,1H,2H,2H-heptadecyl acrylate, 13 parts by weight of methyl methacrylate, 11 parts by weight of acrylic acid, and 18 parts by weight of butyl acrylate were stirred and mixed at 280 r / min for 25 min to obtain a mixture. Under argon protection, 18 parts by weight of the above mixture and 0.28 parts by weight of benzoyl peroxide were dispersed in 100 parts by weight of n-butanol, and the mixture was heated to 108 °C and refluxed for 7.5 h to obtain a modified waterborne acrylic resin.

[0049] Preparation Example 8:

[0050] The preparation of modified waterborne acrylic resin includes the following steps:

[0051] Six parts by weight of thionyl chloride were added to 10 parts by weight of cis-2-buten-1,4-diol, and stirred at 700 r / min for 1 h at 5 °C. Then, 6 parts by weight of levodopa were added, and the mixture was stirred and heated to 90 °C and refluxed for 8 h to obtain an intermediate product. 20 parts by weight of the intermediate product, 3 parts by weight of 1H,1H,2H,2H-heptadecyl acrylate, 15 parts by weight of methyl methacrylate, 12 parts by weight of acrylic acid, and 20 parts by weight of butyl acrylate were stirred and mixed at 300 r / min for 30 min to obtain a mixture. Under nitrogen protection, 20 parts by weight of the above mixture and 0.3 parts by weight of benzoyl peroxide were dispersed in 100 parts by weight of n-butanol, and the mixture was heated to 110 °C and refluxed for 8 h to obtain a modified waterborne acrylic resin.

[0052] Preparation Example 9:

[0053] The preparation of modified waterborne acrylic resin includes the following steps:

[0054] 15 parts by weight of methyl methacrylate, 12 parts by weight of acrylic acid and 20 parts by weight of butyl acrylate were stirred and mixed at 300 r / min for 30 min to obtain a mixture; under nitrogen protection, 20 parts by weight of the above mixture and 0.3 parts by weight of benzoyl peroxide were dispersed in 100 parts by weight of n-butanol, and the mixture was heated to 110℃ and refluxed for 8 h to obtain a modified waterborne acrylic resin.

[0055] Example 1:

[0056] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0057] 10 parts by weight of the composite conductive material prepared in Preparation Example 1, 20 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 5, and 2 parts by weight of polyvinylpyrrolidone were added to 30 parts by weight of the first solvent (V 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 35°C for 4 hours with stirring at 800 r / min.

[0058] Example 2:

[0059] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0060] 13 parts by weight of the composite conductive material prepared in Preparation Example 2, 22 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 6, and 2.5 parts by weight of polyacrylic acid were added to 35 parts by weight of the first solvent (V 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 38°C with a stirring speed of 900 r / min for 4.5 h.

[0061] Example 3:

[0062] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0063] 16 parts by weight of the composite conductive material prepared in Preparation Example 3, 25 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 7, and 3 parts by weight of 2-hydroxyphosphonoacetic acid were added to 40 parts by weight of the first solvent (V 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 42°C with a stirring speed of 1000 r / min for 5 h.

[0064] Example 4:

[0065] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0066] 20 parts by weight of the composite conductive material prepared in Preparation Example 4, 30 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 8, and 4 parts by weight of 2-hydroxyphosphonoacetic acid were added to 50 parts by weight of the first solvent (V 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 45°C with a stirring speed of 1200 r / min for 6 hours.

[0067] Comparative Example 1:

[0068] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0069] 20 parts by weight of carbon nanotubes, 30 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 8, and 4 parts by weight of 2-hydroxyphosphonoacetic acid were added to 50 parts by weight of the first solvent (V). 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 45°C with a stirring speed of 1200 r / min for 6 hours.

[0070] Comparative Example 2:

[0071] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0072] 20 parts by weight of the composite conductive material prepared in Preparation Example 4, 30 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 9, and 4 parts by weight of 2-hydroxyphosphonoacetic acid were added to 50 parts by weight of the first solvent (V 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 45°C with a stirring speed of 1200 r / min for 6 hours.

[0073] Comparative Example 3:

[0074] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0075] 10 parts by weight of carbon nanotubes, 10 parts by weight of polypyrrole, 30 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 8, and 4 parts by weight of 2-hydroxyphosphonoacetic acid were added to 50 parts by weight of the first solvent (V). 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 45°C with a stirring speed of 1200 r / min for 6 hours.

[0076] Comparative Example 4:

[0077] The preparation of an aqueous primer for lithium battery foil includes the following steps:

[0078] 20 parts by weight of the composite conductive material prepared in Preparation Example 4, 25 parts by weight of the modified waterborne acrylic resin prepared in Preparation Example 9, 3 parts by weight of levodopa, and 4 parts by weight of 2-hydroxyphosphonoacetic acid were added to 50 parts by weight of the first solvent (V 去离子水 V 乙醇 A water-based primer was prepared by mixing the mixture in a ratio of 5:1 at 45°C with a stirring speed of 1200 r / min for 6 hours.

[0079] Performance testing:

[0080] The aqueous primers prepared in Examples 1-4 and Comparative Examples 1-4 were coated onto aluminum foil, and then vacuum dried at 60°C for 3 hours. After drying at 120°C for 2 hours, eight types of aluminum foil for lithium batteries were obtained. The performance of the eight types of aluminum foil for lithium batteries obtained above was tested.

[0081] 1. Conductivity test: The resistance of the above 8 types of aluminum foil for lithium batteries was tested using a Changzhou Amber AT256 probe tester. The test results are shown in Table 1.

[0082] 2. Adhesion test: Lithium iron phosphate slurry was coated onto the above eight types of aluminum foil for lithium batteries, and each was made with an areal density of 300 g / m³. 2 The compacted density is 2.4 g / cm³. 3 The adhesion of the electrode was tested, and the test results are shown in Table 1.

[0083] 3. Electrolyte resistance test: The electrolyte composition was EC:EDC = 1:1, with a LiPF6 concentration of 1M. The above 8 types of lithium batteries were immersed in the electrolyte using aluminum foil in a sealed environment at 85°C for 24 hours. After wiping off the electrolyte with water, the surface corrosion was observed. The test results are shown in Table 1.

[0084] Table 1. Performance Testing

[0085] Resistance (Ω) Adhesion (N) Resistance to electrolyte Example 1 1.5 0.81 Good Example 2 1.3 0.85 Good Example 3 1.1 0.87 Good Example 4 0.9 0.89 Good Comparative Example 1 2.5 0.53 General Comparative Example 2 1.9 0.26 Poor Comparative Example 3 2.1 0.67 General Comparative Example 4 1.7 0.37 Poor

[0086] According to the data in Table 1, it is evident that the aqueous primers prepared in Examples 1-4 exhibit excellent performance when coated on lithium battery aluminum foil. Compared to Comparative Examples 1-4, Examples 1-4 show lower resistance, stronger adhesion, and better electrolyte resistance. These results fully demonstrate the superiority of the aqueous primers prepared in Examples 1-4 in terms of electrochemical performance, adhesion, and electrolyte resistance. Further comparison of Comparative Examples 1-4 with Example 4 reveals a decrease in electrochemical performance, adhesion, and electrolyte resistance. This phenomenon indicates a significant synergistic effect among the various materials used in Examples 1-4, which collectively enhances the overall performance of the aqueous primers.

[0087] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing an aqueous primer for lithium battery foil, characterized in that, The preparation method includes the following steps: The composite conductive material, modified waterborne acrylic resin and dispersant are added to the first solvent and stirred and mixed at 800-1200 r / min for 4-6 h at 35-45℃ to obtain the waterborne primer. The preparation method of the composite conductive material includes the following steps: Hydroxylated multi-walled carbon nanotubes and diethoxy(3-glycidyloxypropyl)methylsilane were mixed and heated to 60–65 °C to obtain epoxy-based carbon nanotubes. Under an inert gas atmosphere, the epoxy-based carbon nanotubes and 1-aminopyrrole were mixed and heated to 60–70 °C to obtain pyrrole-containing ring-based carbon nanotubes. The composite conductive material was prepared by stirring and polymerizing the pyrrole-containing ring-based carbon nanotubes, pyrrole monomers, and anhydrous ferric chloride. The preparation method of the modified waterborne acrylic resin includes the following steps: After mixing cis-2-butene-1,4-diol and thionyl chloride at 0–5 °C, levodopa was added and the mixture was stirred at 80–90 °C to obtain an intermediate product. The intermediate product, 1H,1H,2H,2H-heptadecyl acrylate, methyl methacrylate, acrylic acid, and butyl acrylate were mixed to obtain a mixture. Under an inert gas atmosphere, the mixture was mixed with benzoyl peroxide at 100–110 °C to prepare the modified waterborne acrylic resin.

2. The method for preparing an aqueous primer for lithium battery foil as described in claim 1, characterized in that, The weight ratio of the hydroxylated multi-walled carbon nanotubes to diethoxy(3-glycidoxypropyl)methylsilane is 1:6-8.

3. The method for preparing an aqueous primer for lithium battery foil as described in claim 1, characterized in that, The weight ratio of the epoxy-based carbon nanotubes to 1-aminopyrrole is 1:3 to 5.

4. The method for preparing an aqueous primer for lithium battery foil as described in claim 1, characterized in that, The weight ratio of the pyrrole-containing carbon nanotubes, pyrrole monomers, and anhydrous ferric chloride is 1:0.5-2.5:0.3-0.

8.

5. The method for preparing an aqueous primer for lithium battery foil as described in claim 1, characterized in that, The weight ratio of cis-2-butene-1,4-diol, thionyl chloride, and levodopa is 1:0.5-0.6:0.4-0.

6.

6. The method for preparing an aqueous primer for lithium battery foil as described in claim 1, characterized in that, The weight ratio of the intermediate product, 1H,1H,2H,2H-heptadecyl acrylate, methyl methacrylate, acrylic acid, and butyl acrylate is 1–2:0.2–0.3:1–1.5:0.8–1.2:1.5–2.

7. The method for preparing an aqueous primer for lithium battery foil as described in claim 1, characterized in that, The weight ratio of the mixture to benzoyl peroxide is 10-20:0.2-0.

3.

8. The method for preparing an aqueous primer for lithium battery foil as described in claim 1, characterized in that, The weight ratio of the composite conductive material, modified waterborne acrylic resin, dispersant, and first solvent is 10-20:20-30:2-4:30-50.