Electrolyte-resistant and anti-aging composite current collector base film

Abstract

The application relates to the field of composite current collector base film materials, and particularly discloses an electrolyte-resistant and anti-aging composite current collector base film, raw materials of which include, in terms of weight parts, 80-100 parts of PET resin, 7-22 parts of PEN resin, 2-4.5 parts of a coupling agent, 0.5-2 parts of a lubricant, and 14-25 parts of anti-aging and barrier-enhancing fillers; the anti-aging and barrier-enhancing fillers are prepared through the following steps: S1, in-situ synthesis of mesoporous silica on halloysite nanotubes; S2, assembly with mica sheets; S3, loading of an antioxidant after surface modification; and S4, grafting of a binary copolymer. The electrolyte-resistant and anti-aging composite current collector base film can comprehensively improve the electrolyte corrosion resistance, anti-aging property and heat resistance of the PET-based base film, and can also improve the bonding strength between the base film and a metal plating layer on the surface of the base film during application.

Description

Technical Field

[0001] This invention relates to the field of composite current collector base film materials, and particularly to an electrolyte-resistant and anti-aging composite current collector base film. Background Technology

[0002] Composite current collectors typically use PET or PP films as the base film, then deposit metal layers such as copper or aluminum on both sides to form a three-layer composite structure of "metal-PET / PP-metal". Compared to traditional current collectors (aluminum foil or copper foil), composite current collectors can reduce the amount of metal used, increase energy density and safety, and therefore have been widely used. For example, patent CN121123160B discloses a composite current collector based on PP / PET base film and its production process; patent CN120842812B discloses a polymer base film for composite current collectors and its preparation method; patent CN120399305B discloses a base film for composite current collectors modified with SiO2 nanocomposite and its preparation method; and patent CN118791770B discloses a modified polyester film resistant to electrolyte corrosion and its application in composite current collectors.

[0003] PET film, due to its high mechanical strength and surface energy, is one of the materials widely used as the base film for composite current collectors. However, as a composite current collector base film, it also needs to have good resistance to electrolyte corrosion, which PET film lacks. In addition, composite current collectors usually need to operate in a certain high-temperature environment, which poses a significant challenge to their heat aging resistance and thermal stability, requirements that pure PET film often cannot meet.

[0004] Adding other modified components to PET is a common way to improve the aforementioned shortcomings of PET. For example, antioxidants can be added to improve the aging resistance of PET resin. However, in the prior art, antioxidants are usually added directly to the raw materials and blended with PET resin. The antioxidants in the base film prepared by this process are prone to gradually losing their effectiveness due to surface migration and other problems, and the antioxidant effect they provide is relatively short-lived. If the amount of antioxidant added is increased to prolong its action time, it is easy to cause a loss of mechanical properties such as strength and toughness of the system, as well as negative impacts such as increased cost.

[0005] Constructing a sustained-release system to continuously release antioxidants into the PET base film system can effectively improve long-term antioxidant performance. However, ordinary sustained-release systems usually do not have controllable sustained-release rate characteristics, resulting in low flexibility when facing the needs of base film products in different application environments.

[0006] Therefore, it is now necessary to improve existing technologies to provide more reliable solutions. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an electrolyte-resistant and anti-aging composite current collector base film that addresses the shortcomings of the prior art.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is: an electrolyte-resistant and anti-aging composite current collector base film, the raw materials for which are prepared by weight include: 80-100 parts of PET resin, 7-22 parts of PEN resin, 2-4.5 parts of coupling agent, 0.5-2 parts of lubricant, and 14-25 parts of anti-aging-barrier reinforcing filler. The anti-aging-barrier-reinforced filler is prepared through the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite. S2. Assemble the first composite with mica sheets to obtain the second composite; S3. After surface modification of the second composite, an antioxidant is loaded to obtain an antioxidant composite. S4. Grafting a binary copolymer onto an antioxidant composite yields an anti-aging-barrier-reinforced filler.

[0009] Preferably, the anti-aging-barrier reinforced filler is prepared by the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite: S1-1. Halloysite nanotubes and tetraethyl orthosilicate are dispersed in ethanol to obtain solution A; CTAB and ammonia are added to deionized water to obtain solution B. S1-2. Add solution B dropwise to solution A, stir to react, then transfer the product to a reaction vessel and react at 90-120℃ for 6-24 hours. Centrifuge, wash the precipitate, dry and calcine to obtain the first complex. S2. Assemble the first composite with mica sheets to obtain the second composite: S2-1. Add mica sheets to hydrochloric acid solution, heat and sonicate, centrifuge, wash the precipitate until neutral, and dry to obtain pretreated mica sheets; S2-2. Pretreated mica flakes and cerium chloride are dispersed in deionized water to obtain dispersion 1; the first complex is dispersed in a mixture of ethanol and deionized water to obtain dispersion 2. S2-3. Add dispersion 2 to dispersion 1, ultrasonically disperse, adjust pH to alkaline, stir, transfer the obtained product to a reaction vessel, react at 140-180℃ for 12-48h, centrifuge, precipitate, wash, dry, grind, and obtain the second complex. S3. After surface modification of the second composite, an antioxidant is loaded to obtain an antioxidant composite: S3-1. The second complex is dispersed in a mixture of deionized water and ethanol, silane coupling agent KH570 is added, the mixture is heated and stirred under reflux, centrifuged, the precipitate is washed and dried to obtain the modified second complex. S3-2. The modified second complex was added to the antioxidant solution, ultrasonically dispersed, and then allowed to stand under vacuum. After centrifugation, the precipitate was washed and dried to obtain the antioxidant complex. S4. Grafting a binary copolymer onto the antioxidant complex yields an anti-aging-barrier-reinforced filler: Antioxidant multi-component composite particles were dispersed in toluene to obtain mixture A; glycidyl methacrylate, methyl methacrylate, emulsifier OP-10, and benzoyl peroxide were added to toluene to obtain mixture B. Mixture B was added to mixture A, nitrogen gas was passed through and stirred, the temperature was raised, and the reaction was carried out under nitrogen protection. After the reaction was completed, the mixture was filtered, and the solid product was washed and dried to obtain anti-aging-barrier reinforcing filler.

[0010] Preferably, the halloysite nanotubes in step S1 are pretreated by the following method: Halloysite nanotubes were calcined, cooled, and then added to a hydrochloric acid solution. The mixture was heated and stirred, centrifuged, and the precipitate was washed until neutral. The precipitate was then dried to complete the pretreatment.

[0011] Preferably, the antioxidant in the antioxidant solution of step S3 is selected from at least one of antioxidant 168, antioxidant 1010, antioxidant 1076, antioxidant 330, 1076, antioxidant 626, antioxidant 618, and antioxidant PL-440.

[0012] Preferably, step S1 specifically includes: S1-0. Calcine halloysite nanotubes at 450-600℃ for 2-8 hours, cool to room temperature, and add to a hydrochloric acid solution with a concentration of 1-4 mol / L. Control the concentration of halloysite nanotubes to 0.01-0.05 g / mL, stir at 60-80℃ for 2-8 hours, centrifuge, wash the precipitate until neutral, and dry to complete the pretreatment of halloysite nanotubes. S1-1: Take 0.5-2g of pretreated halloysite nanotubes and 0.8-2mL of tetraethyl orthosilicate and add them to 50-200mL of ethanol. Disperse by ultrasonication for 0.5-2h to obtain solution A; Take 0.6-2.4g of CTAB and 1-4mL of 15-28wt% ammonia solution and add them to 10-40mL of deionized water. Stir for 2-10min to obtain solution B. S1-2. Add solution B dropwise to solution A with stirring. After the addition is complete, stir the reaction for 0.5-2 hours. Then transfer the product to a reaction vessel and react at 90-120℃ for 6-24 hours. Centrifuge, wash the precipitate with deionized water, dry it at 70-100℃ for 4-16 hours, and then calcine it at 500-600℃ for 2-4 hours to obtain the first complex.

[0013] Preferably, step S2 specifically includes: S2-1. Add 0.5-2g of mica sheets to 25-100mL of 5-20wt% hydrochloric acid solution, sonicate at 40-60℃ for 3-12h, centrifuge, wash the precipitate with deionized water until neutral, and then dry at 100-130℃ for 6-24h to obtain pretreated mica sheets. S2-2, Add 0.5-2g of pretreated mica sheets and 0.35-1.3g of cerium chloride to 50-200mL of deionized water, and ultrasonically disperse for 0.5-2h to obtain dispersion 1; Add 0.75-3g of the first complex to a mixture of 60-200mL of ethanol and deionized water in a volume ratio of 1:1, and ultrasonically disperse for 0.5-2h to obtain dispersion 2; S2-3. Add dispersion 2 to dispersion 1 under stirring, and sonicate for 1-3 hours. Then, add 10-25 wt% ammonia water to adjust the pH to 8-10, stir for 0.5-2 hours, transfer the obtained product to a reaction vessel, react at 140-180℃ for 12-48 hours, cool to room temperature, centrifuge, wash the precipitate with deionized water, vacuum dry at 80-100℃ for 12-36 hours, grind, and obtain the second complex.

[0014] Preferably, step S3 specifically includes: S3-1. Add 1-4g of the second complex to a mixture of 75-300mL of deionized water and ethanol in a volume ratio of 1:7, and sonicate for 0.5-2h. Add 0.4-1.6g of silane coupling agent KH570 while stirring, and reflux at 65-80℃ for 3-12h. Centrifuge, wash the precipitate with ethanol, and vacuum dry at 70-100℃ for 6-24h to obtain the modified second complex. S3-2. Add 0.5-2g of the modified second complex to 25-100mL of a cyclohexane solution containing 4-15% antioxidant 168, and sonicate for 1-4h. Then, let it stand for 3-12h at 40-60℃ and -0.1MPa vacuum, centrifuge, wash the precipitate with cyclohexane and ethanol sequentially, and dry it under vacuum at 90-100℃ for 6-24h to obtain the antioxidant complex.

[0015] Preferably, step S4 specifically includes: Add 0.5-3g of antioxidant multi-component composite particles to 25-100mL of toluene and ultrasonically disperse for 30-90min to obtain mixture A. Add 1.25-5g of glycidyl methacrylate, 0.9-3.6g of methyl methacrylate, 0.1-0.4g of emulsifier OP-10, and 0.05-0.2g of benzoyl peroxide to 25-100mL of toluene and stir for 5-30min. Then add the mixture to mixture A, purge with nitrogen and stir for 30-90min. Heat to 70-85℃ and stir under nitrogen protection for 5-20h. Cool to room temperature, filter, wash the solid product with toluene and ethanol sequentially, and vacuum dry at 70-95℃ for 6-24h to obtain the anti-aging-barrier-reinforcing filler.

[0016] Preferably, the lubricant is selected from at least one of N,N-ethylene bis-stearamide, pentaerythritol stearate, calcium stearate, and zinc stearate; The coupling agent is selected from at least one of silane coupling agent A-151, silane coupling agent A-171, silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0017] Preferably, the anti-aging-barrier reinforced filler is prepared by the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite: S1-0. Halloysite nanotubes are pretreated by the following steps to remove impurities and expand pores: Halloysite nanotubes were calcined at 500℃ for 4 hours, cooled to room temperature, and then added to a 2 mol / L hydrochloric acid solution. The concentration of halloysite nanotubes was controlled at 0.02 g / mL. The mixture was stirred at 70℃ for 4 hours, centrifuged, and the precipitate was washed until neutral. It was then dried at 90℃ for 12 hours to obtain pretreated halloysite nanotubes. S1-1. Take 1g of pretreated halloysite nanotubes and 1.85mL of tetraethyl orthosilicate and add them to 100mL of ethanol. Disperse them by ultrasonication for 1h to obtain solution A. Take 1.2g of cetyltrimethylammonium bromide (CTAB) and 2mL of 25wt% ammonia water and add them to 20mL of deionized water. Stir for 5min to obtain solution B. S1-2. Add solution B dropwise to solution A under stirring. After the addition is complete, stir the reaction at 1000 rpm for 1 h. Then transfer the product to a reaction vessel and react at 100 °C for 12 h. Centrifuge, wash the precipitate with deionized water, dry it at 90 °C for 8 h, and then calcine it at 550 °C for 4 h to obtain the mesoporous silica-haloite nanotube composite, i.e., the first composite. S2. Assemble the first composite with mica sheets to obtain the second composite: S2-1. Add 1g of mica sheet to 50mL of 10wt% hydrochloric acid solution, sonicate at 50℃ for 6h, centrifuge, wash the precipitate with deionized water until neutral, and then dry at 110℃ for 12h to obtain pretreated mica sheet. S2-2. Add 1g of pretreated mica sheet and 0.65g of cerium chloride to 100mL of deionized water and sonicate for 1h to obtain dispersion 1; add 1.5g of the first complex to a mixture of 120mL of ethanol and deionized water in a volume ratio of 1:1 and sonicate for 1h to obtain dispersion 2. S2-3. Under stirring, add dispersion 2 to dispersion 1, sonicate for 1.5 h, then add 20 wt% ammonia water to adjust the pH to 9, stir at 1200 rpm for 1 h, transfer the obtained product to a reaction vessel, react at 160℃ for 24 h, cool to room temperature, centrifuge, wash the precipitate with deionized water, vacuum dry at 90℃ for 24 h, grind to obtain mesoporous silica-haloite nanotube-mica sheet composite, i.e., the second composite. S3. After surface modification of the second composite, an antioxidant is loaded to obtain an antioxidant composite: S3-1. Add 2g of the second complex to a mixture of 150mL of deionized water and ethanol in a volume ratio of 1:7, sonicate for 1h, add 0.8g of silane coupling agent KH570 under stirring, stir and reflux at 75℃ for 6h, centrifuge, wash the precipitate with ethanol, and vacuum dry at 90℃ for 12h to obtain the modified second complex. S3-2. Add 1g of the modified second complex to 50mL of cyclohexane solution with a concentration of 10% antioxidant 168, sonicate for 2h, then let stand for 6h at 50℃ and -0.1MPa vacuum, centrifuge, wash the precipitate with cyclohexane and ethanol in sequence, and dry under vacuum at 100℃ for 12h to obtain the antioxidant complex. S4. Grafting a binary copolymer (methyl methacrylate-glycidyl methacrylate copolymer) onto the antioxidant complex yields an anti-aging-barrier-reinforcing filler: 1.5g of antioxidant multi-component composite particles were added to 50mL of toluene and ultrasonically dispersed for 45min to obtain mixture A. 2.5g of glycidyl methacrylate, 1.8g of methyl methacrylate, 0.2g of emulsifier OP-10, and 0.1g of benzoyl peroxide were added to 50mL of toluene and stirred for 15min. This mixture was then added to mixture A, and the mixture was stirred under nitrogen for 60min. The temperature was raised to 75℃, and the reaction was carried out under nitrogen protection for 10h. The mixture was cooled to room temperature, filtered, and the solid product was washed sequentially with toluene and ethanol. The product was then vacuum dried at 90℃ for 12h to obtain the anti-aging-barrier-reinforcing filler.

[0018] Preferably, the electrolyte-resistant and anti-aging composite current collector substrate film is prepared by the following steps: PET resin, PEN resin, coupling agent, lubricant, and anti-aging-barrier reinforcing filler are mixed evenly according to the weight ratio. The resulting mixture is melt-extruded at 250-265℃, cooled, cast, and biaxially stretched to obtain an electrolyte-resistant and anti-aging composite current collector base film.

[0019] The beneficial effects of this invention are: This invention provides an electrolyte-resistant and anti-aging composite current collector base film, which is made by compounding PEN resin and PET resin and adding a self-made anti-aging-barrier reinforcing filler. This comprehensively improves the electrolyte corrosion resistance, aging resistance and heat resistance of the PET-based base film, and also improves the bonding strength between the base film and the metal coating on its surface during application.

[0020] In this invention, the controlled release rate of the anti-aging-barrier-enhancing filler can be regulated by adjusting the ratio of halloysite nanotubes and mesoporous silica. Specifically, increasing the proportion of mesoporous silica increases the proportion of small-pore structures, enhancing the "second-order controlled release characteristic" and ultimately reducing the antioxidant controlled release rate of the anti-aging-barrier-enhancing filler. This results in a longer-lasting antioxidant controlled release effect, suitable for applications with relatively mild environments and longer design lifespans. Conversely, decreasing the proportion of mesoporous silica increases the controlled release rate, making it suitable for applications with high temperatures or higher oxidizing agents. This rate-adjustable controlled-release structure design provides greater flexibility in its application in base films, better meeting the needs of different usage scenarios.

[0021] In this invention, mica sheets and mesoporous silica-haloite nanotube composites are assembled into ternary composite particles. In these composite particles, halloysite nanotubes with a high aspect ratio form a framework support structure, while two-dimensional sheet-like mica sheets form a planar support structure. The interweaving of the two can construct a micro-network structure, which enables both to synergistically enhance the strength, barrier properties, and heat resistance of the base film.

[0022] In this invention, by in-situ grafting methyl methacrylate-glycidyl methacrylate copolymer onto the surface of an antioxidant composite, the problem of poor compatibility between mica sheets, mesoporous silica, halloysite nanotubes and the PET system can be solved simultaneously, enabling the uniform dispersion of the final anti-aging-barrier reinforcing filler in the PET base film; the copolymer can also simultaneously improve the compatibility between PEN resin and PET resin in the base film raw material. Attached Figure Description

[0023] Figure 1 The results are from the test on the controllable adjustment of the sustained-release performance of the present invention; Figure 2The XRD pattern of the second complex prepared in Example 1; Figure 3 Tensile breaking strength test results of the composite current collector base film prepared for the examples and comparative examples; Figure 4 The results of the heat and oxygen aging resistance test of the composite current collector base film prepared for the examples and comparative examples; Figure 5 The thermal shrinkage rate test results of the composite current collector base film prepared for the examples and comparative examples; Figure 6 The results show the bonding performance test results of the composite current collector substrate film and the copper layer prepared for the examples and comparative examples. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0025] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0026] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0027] This invention provides an electrolyte-resistant and anti-aging composite current collector base film, the raw materials for which are prepared by weight include: 80-100 parts of PET resin, 7-22 parts of PEN resin, 2-4.5 parts of coupling agent, 0.5-2 parts of lubricant, and 14-25 parts of anti-aging-barrier reinforcing filler. The base film is prepared by the following steps: PET resin, PEN resin, coupling agent, lubricant, and anti-aging-barrier reinforcing filler are mixed evenly according to the weight ratio, and the resulting mixture is melt-extruded at 250-265℃, cooled, cast, and biaxially stretched to obtain an electrolyte-resistant and anti-aging composite current collector base film.

[0028] Anti-aging-barrier reinforced filler is prepared through the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite: S1-0. Calcine halloysite nanotubes at 450-600℃ for 2-8 hours, cool to room temperature, and add to a hydrochloric acid solution with a concentration of 1-4 mol / L. Control the concentration of halloysite nanotubes to 0.01-0.05 g / mL, stir at 60-80℃ for 2-8 hours, centrifuge, wash the precipitate until neutral, and dry to complete the pretreatment of halloysite nanotubes. S1-1: Take 0.5-2g of pretreated halloysite nanotubes and 0.8-2mL of tetraethyl orthosilicate and add them to 50-200mL of ethanol. Disperse by ultrasonication for 0.5-2h to obtain solution A; Take 0.6-2.4g of CTAB and 1-4mL of 15-28wt% ammonia solution and add them to 10-40mL of deionized water. Stir for 2-10min to obtain solution B. S1-2. Add solution B dropwise to solution A with stirring. After the addition is complete, stir the reaction for 0.5-2 hours. Then transfer the product to a reaction vessel and react at 90-120℃ for 6-24 hours. Centrifuge, wash the precipitate with deionized water, dry it at 70-100℃ for 4-16 hours, and then calcine it at 500-600℃ for 2-4 hours to obtain the first complex.

[0029] S2. Assemble the first composite with mica sheets to obtain the second composite: S2-1. Add 0.5-2g of mica sheets to 25-100mL of 5-20wt% hydrochloric acid solution, sonicate at 40-60℃ for 3-12h, centrifuge, wash the precipitate with deionized water until neutral, and then dry at 100-130℃ for 6-24h to obtain pretreated mica sheets. S2-2, Add 0.5-2g of pretreated mica sheets and 0.35-1.3g of cerium chloride to 50-200mL of deionized water, and ultrasonically disperse for 0.5-2h to obtain dispersion 1; Add 0.75-3g of the first complex to a mixture of 60-200mL of ethanol and deionized water in a volume ratio of 1:1, and ultrasonically disperse for 0.5-2h to obtain dispersion 2; S2-3. Add dispersion 2 to dispersion 1 under stirring, and sonicate for 1-3 hours. Then, add 10-25 wt% ammonia water to adjust the pH to 8-10, stir for 0.5-2 hours, transfer the obtained product to a reaction vessel, react at 140-180℃ for 12-48 hours, cool to room temperature, centrifuge, wash the precipitate with deionized water, vacuum dry at 80-100℃ for 12-36 hours, grind, and obtain the second complex.

[0030] S3. After surface modification of the second composite, an antioxidant is loaded to obtain an antioxidant composite: S3-1. Add 1-4g of the second complex to a mixture of 75-300mL of deionized water and ethanol in a volume ratio of 1:7, and sonicate for 0.5-2h. Add 0.4-1.6g of silane coupling agent KH570 while stirring, and reflux at 65-80℃ for 3-12h. Centrifuge, wash the precipitate with ethanol, and vacuum dry at 70-100℃ for 6-24h to obtain the modified second complex. S3-2. Add 0.5-2g of the modified second complex to 25-100mL of a cyclohexane solution containing 4-15% antioxidant 168, and sonicate for 1-4h. Then, let it stand for 3-12h at 40-60℃ and -0.1MPa vacuum, centrifuge, wash the precipitate with cyclohexane and ethanol sequentially, and dry it under vacuum at 90-100℃ for 6-24h to obtain the antioxidant complex.

[0031] S4. Grafting a binary copolymer onto the antioxidant complex yields an anti-aging-barrier-reinforced filler: Add 0.5-3g of antioxidant multi-component composite particles to 25-100mL of toluene and ultrasonically disperse for 30-90min to obtain mixture A. Add 1.25-5g of glycidyl methacrylate, 0.9-3.6g of methyl methacrylate, 0.1-0.4g of emulsifier OP-10, and 0.05-0.2g of benzoyl peroxide to 25-100mL of toluene and stir for 5-30min. Then add the mixture to mixture A, purge with nitrogen and stir for 30-90min. Heat to 70-85℃ and stir under nitrogen protection for 5-20h. Cool to room temperature, filter, wash the solid product with toluene and ethanol sequentially, and vacuum dry at 70-95℃ for 6-24h to obtain the anti-aging-barrier-reinforcing filler.

[0032] In a preferred embodiment, the lubricant is selected from at least one of N,N-ethylene bis-stearamide, pentaerythritol stearate, calcium stearate, and zinc stearate; the coupling agent is selected from at least one of silane coupling agent A-151, silane coupling agent A-171, silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0033] This invention, by compounding PEN resin and PET resin and adding a self-made anti-aging and barrier reinforcing filler, comprehensively improves the electrolyte corrosion resistance, aging resistance, and heat resistance of PET-based base films. It also improves the bonding strength between the base film and the metal coating on its surface during application. The mechanism of this invention is explained in detail below to facilitate understanding.

[0034] I. PEN resin (polyethylene naphthalate) is formed by the condensation polymerization of 2,6-naphthalenedicarboxylic acid (NDC) or dimethyl 2,6-naphthalenedicarboxylic acid (DMN) with ethylene glycol. The chemical structure of PEN is similar to that of PET, but the difference lies in the molecular chain. In PEN, the more rigid naphthalene ring replaces the benzene ring in PET. This naphthalene ring structure gives PEN higher physical and mechanical properties, gas barrier properties, chemical stability, and heat resistance than PET. Because the naphthalene structure in the molecular chain is more likely to be planar, PEN exhibits excellent barrier properties, resulting in better aging resistance. The presence of the naphthalene structure also significantly improves the heat resistance of PEN compared to PET. PEN has good chemical stability, is stable to organic solvents and chemicals, and has better acid and alkali resistance than PET. Therefore, by compounding PEN resin into PET resin, the corrosion resistance, heat resistance, and aging resistance of PET resin can be improved.

[0035] The addition of coupling agents to the raw materials can promote the uniform dispersion of anti-aging-barrier reinforcing fillers and improve interfacial adhesion strength.

[0036] II. The self-made anti-aging-barrier-reinforcing filler in this invention is a multi-component composite particle formed by halloysite nanotubes, mesoporous silica, and mica sheets. Its preparation process is as follows: (1) First, halloysite nanotubes are purified and expanded by calcination and acid leaching to increase the inner diameter of the halloysite nanotubes, so as to facilitate the loading of antioxidants in the future. Then, using tetraethyl orthosilicate as the silicon source and hexadecyltrimethylammonium bromide as the mesoporous structure directing agent, mesoporous silica was synthesized in situ on halloysite nanotubes via a hydrothermal method combined with high-temperature calcination. During this process, the mesoporous silica can mainly fill the interior of the halloysite nanotubes, thereby achieving a more uniform and smaller size through the confinement effect of the halloysite nanotubes, and forming a firmly bonded mesoporous silica-haloysite nanotube composite, namely the first composite.

[0037] Halloysite nanotubes (HNTs) have different compositions inside and outside. The inner wall of the tube is mainly composed of Al-OH groups, while the outer surface is mainly composed of Si-O-Si groups. Therefore, the inner and outer surfaces of HNTs carry positive and negative charges, respectively (Zhao Puxiang, Feng Yue, Long Yuanhui, et al. A review of halloysite nanotube filling modification technology [J]. Materials Research and Application, 2022(003):016.). During the in-situ deposition of mesoporous silica, tetraethyl orthosilicate hydrolyzes under alkaline conditions, producing negatively charged silica particles. These negatively charged silica particles repel the negatively charged groups on the outside of halloysite nanotubes, but attract the positively charged groups inside the tubes. This allows the silica particles to enter the interior of the halloysite nanotubes, where they precipitate silica. After calcination, the silica is further precipitated to form mesoporous silica. Therefore, the mesoporous silica formed mainly fills the interior of the halloysite nanotubes, with a small amount possibly deposited on the outer wall of the nanotubes.

[0038] (3) The pretreated mica sheets were then mixed with the mesoporous silica-haloysite nanotube composite, with cerium chloride as the co-processing component, and subjected to a one-pot hydrothermal treatment to prepare the mesoporous silica-haloysite nanotube-mica sheet composite, i.e., the second composite. During this process, Ce... 3+ It can bind to the hydroxyl groups on the surface of halloysite nanotubes and mica sheets through electrostatic adsorption and / or coordination, thereby playing a role in bonding. Then, under high temperature and hydrothermal conditions, cerium dioxide is formed, which enables a strong connection between halloysite nanotubes and mica sheets through cerium dioxide as a bonding agent, forming a strong and uniformly mixed complex.

[0039] (4) Next, the surface of the mesoporous silica-haloite nanotube-mica sheet composite was modified by using silane coupling agent KH570 to introduce double bonds. Then, by impregnation, antioxidant 168 was loaded onto the mesoporous silica-haloite nanotube-mica sheet composite using the cavity structure of halloysite nanotubes and the mesoporous structure of mesoporous silica to obtain an antioxidant composite.

[0040] (5) Finally, using glycidyl methacrylate and methyl methacrylate as monomers, an in-situ polymerization process was used to graft methyl methacrylate-glycidyl methacrylate copolymer onto the surface of the antioxidant complex, ultimately obtaining an anti-aging-barrier reinforcing filler. During the grafting process, the double bonds introduced on the surface of the antioxidant complex through the silane coupling agent KH570 can participate in the polymerization reaction, thereby enabling the methyl methacrylate-glycidyl methacrylate copolymer to be firmly and uniformly grafted onto the antioxidant complex.

[0041] The main mechanism of action of anti-aging-barrier reinforced fillers is explained below: 1. A composite formed by mesoporous silica and halloysite nanotubes (1) Halloysite nanotubes can effectively improve the mechanical strength of the base film and accelerate the crystallization rate of PET, thereby improving its stability and heat resistance (Xing Tianhao, Luo Chunming, Tang Anbin. Preparation and performance study of PET / modified halloysite nanotube composite film [J]. Journal of Southwest University of Science and Technology, 2015, 30(1):4.DOI:10.3969 / j.issn.1671-8755.2015.01.003.). In addition, halloysite nanotubes form tortuous paths in the PET matrix, which can improve its barrier properties (Xing Tianhao. Barrier properties study of PET / haloysite composite film [D]. Southwest University of Science and Technology, 2016.), thereby enhancing its acid and alkali resistance and antioxidant properties.

[0042] (2) This invention constructs a composite loading system with multi-sized pore structures and adjustable sustained-release rate by filling halloysite nanotubes with elongated tubular structures with loaded mesoporous silica, thus combining two particles with different pore structure parameters: Halloysite nanotubes have a tubular structure with typical parameters: an outer diameter of 10-50 nm, an inner diameter of 10-20 nm, and a length of 0.5-2 μm. After the pore-expanding treatment of this invention, the inner diameter of the tube can reach 15-35 nm. The mesoporous silica filling the tube cavity of the halloysite nanotube has a mesoporous structure smaller than the inner diameter of the halloysite nanotube, thus forming two different pore sizes: a large pore structure formed by the halloysite nanotube cavity and a small pore structure formed by the mesoporous silica.

[0043] By loading antioxidants onto the nanoporous structure of the mesoporous silica-haloite nanotube-mica sheet composite, a sustained release of antioxidants can be achieved. This allows for longer-lasting antioxidant protection through prolonged release, solving the problem of short-lasting effects caused by antioxidant migration and rapid loss in conventional addition methods. It also effectively avoids the risk of damaging the mechanical properties of the base film due to high initial antioxidant concentrations.

[0044] The size of the pore structure affects the slow-release rate; the larger the pores, the faster the release rate. Therefore, when the mesoporous silica-halothite nanotube-mica sheet composite is loaded with antioxidants, the slow-release rate of the antioxidants loaded in the lumen of the halloysite nanotubes will be greater than that of the mesoporous silica. Furthermore, the antioxidants released from the mesoporous silica located inside the lumen of the halloysite nanotubes will first enter the lumen of the halloysite nanotubes and then be released to the outside, thus exhibiting a "second-order slow-release characteristic." This characteristic further increases the difference in slow-release rates between halloysite nanotubes and mesoporous silica, specifically making the release rate of the latter even lower than that of the former.

[0045] Therefore, the controlled release rate of the anti-aging-barrier-enhancing filler can be regulated by adjusting the ratio of halloysite nanotubes to mesoporous silica. Specifically, increasing the proportion of mesoporous silica increases the proportion of small-pore structures, strengthening the "second-order controlled release characteristic" and ultimately reducing the antioxidant controlled release rate of the anti-aging-barrier-enhancing filler, thus achieving a longer-lasting antioxidant controlled release effect. This is suitable for applications with relatively mild environments and longer design lifespans. Conversely, decreasing the proportion of mesoporous silica increases the controlled release rate, making it suitable for applications with high temperatures or higher oxidizing agents. This rate-adjustable controlled release structure design allows for greater flexibility in its application in base films, better meeting the needs of different application scenarios.

[0046] 2. Mesoporous silica-halothite nanotube-mica sheet composite Mica sheets have a two-dimensional sheet structure and a high modulus, which can improve the tensile strength of PET base film; its two-dimensional sheet structure forms a barrier effect, which can improve the corrosion resistance and oxidation resistance of PET base film; and mica sheets have strong thermal stability, which can effectively reduce the coefficient of thermal expansion of the material and improve its heat resistance.

[0047] Furthermore, in this invention, mica sheets and mesoporous silica-haloite nanotube composites are assembled into ternary composite particles. In these composite particles, halloysite nanotubes with a high aspect ratio form a framework support structure, while two-dimensional sheet-like mica sheets form a planar support structure. The interweaving of the two can construct a micro-network structure, thereby achieving a synergistic enhancement effect on the strength, barrier properties, and heat resistance of the base film.

[0048] Furthermore, the cerium dioxide formed by doping in the mesoporous silica-haloite nanotube-mica sheet composite not only plays a role in the preparation process, but also can efficiently scavenge reactive oxygen free radicals through its reversible redox properties, thereby playing an auxiliary role in improving anti-aging performance.

[0049] Furthermore, the mesoporous silica-halothite nanotube-mica sheet composite contains abundant hydroxyl groups, which are beneficial for enhancing the adhesion between the base film and the metal layer deposited on its surface. For example, when a copper layer is deposited on the base film surface by electroplating, hydroxyl groups can combine with copper ions through coordination and electrostatic adsorption, thereby promoting the rapid and uniform adhesion of copper ions during the electroplating process, thus improving the electroplating efficiency and the density of the coating, and effectively enhancing the bonding strength between the copper layer and the base film in the later stages.

[0050] 3. Grafting of methyl methacrylate-glycidyl methacrylate copolymer Mica flakes, mesoporous silica, and halloysite nanotubes in the antioxidant composite, as inorganic fillers, all suffer from poor compatibility with the PET organic system. If they cannot achieve uniform dispersion, their aggregation in the PET base film can easily cause negative effects such as damage to the mechanical strength of the base film. In this invention, by in-situ grafting methyl methacrylate-glycidyl methacrylate copolymer onto the surface of the antioxidant composite, the problem of poor compatibility between mica flakes, mesoporous silica, halloysite nanotubes and the PET system can be solved simultaneously, enabling uniform dispersion of the final anti-aging-barrier reinforcing filler in the PET base film. The mechanism of compatibility enhancement is as follows: the epoxy groups of glycidyl methacrylate can chemically react with the terminal hydroxyl (-OH) or terminal carboxyl (-COOH) groups of PET, forming an in-situ copolymer at the blending interface, thereby reducing interfacial tension and enhancing the compatibility between the two phases.

[0051] On the other hand, the methyl methacrylate-glycidyl methacrylate copolymer can also improve the compatibility between PEN resin and PET resin in the base film raw material: (1) Glycidyl methacrylate contains highly reactive epoxy groups, which can undergo ring-opening reactions with the hydroxyl (-OH) or carboxyl (-COOH) groups at the end of the PEN or PET molecular chains to form chemical bonds at the interface, thereby enhancing the interfacial adhesion between the two phases; (2) The methyl methacrylate unit has a certain similarity to the ester group structure in PEN / PET, which helps to improve the thermodynamic compatibility of the blend system; while the polar epoxy groups introduced by glycidyl methacrylate can effectively reduce the interfacial tension; (3) During the melt blending process of the raw materials, the methyl methacrylate-glycidyl methacrylate copolymer can act as a "molecular bridge" to achieve interfacial compatibility, thereby improving the mechanical properties and morphological structure of the blend.

[0052] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0053] PET resin, brand: DuPont, USA, purchased from Shanghai Huzi Plastic Raw Materials Co., Ltd. PEN resin (polyethylene naphthalate), brand Teijin Japan, grade TN-80655, purchased from Shanghai Maitian Chemical Co., Ltd. Silane coupling agent KH570, Nanjing Baiju Technology Co., Ltd.; Pentaerythritol stearate, Jiangsu Bost Chemical Technology Co., Ltd.; Halloysite nanotubes, with an outer diameter of approximately 50 nm, an inner diameter of approximately 15 nm, and a length of approximately 1 μm, are produced by Angxing New Carbon Materials Changzhou Co., Ltd. Mica flakes, specifically sericite, with a particle size of 5000 mesh, manufactured by Jiangxi Tuobang New Material Technology Co., Ltd. Antioxidant 168, Jiangsu Bosite Chemical Technology Co., Ltd.; Glycidyl methacrylate, Nantong Runfeng Petrochemical Co., Ltd.; Methyl methacrylate, Nantong Runfeng Petrochemical Co., Ltd.; Emulsifier OP-10, Jiangsu Bosite Chemical Technology Co., Ltd.; Benzoyl peroxide, Jiangsu Bost Chemical Technology Co., Ltd.

[0054] Example 1: An electrolyte-resistant and anti-aging composite current collector base film, characterized in that its raw materials, by weight, include: 90 parts PET resin, 10 parts PEN resin, 3 parts coupling agent, 1 part lubricant, and 18 parts anti-aging-barrier reinforcing filler.

[0055] The preparation process of this electrolyte-resistant and anti-aging composite current collector base film includes the following steps: All the above raw materials were mixed according to the weight ratio and stirred at 85°C for 45 min. The resulting mixture was added to a twin-screw extruder and melt-extruded at 265°C. After cooling, the mixture was cast into sheets. The cast sheets were preheated at 90°C and then longitudinally stretched at 100°C with a stretching ratio of 3.0 times. Then, they were transversely stretched at 110°C with a stretching ratio of 4.5 times. After cooling, an electrolyte-resistant and anti-aging composite current collector base film was obtained.

[0056] The coupling agent is silane coupling agent KH570, and the lubricant is pentaerythritol stearate.

[0057] The anti-aging-barrier-reinforced filler is prepared through the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite: S1-0. Halloysite nanotubes are pretreated by the following steps to remove impurities and expand pores: Halloysite nanotubes were calcined at 500℃ for 4 hours, cooled to room temperature, and then added to a 2 mol / L hydrochloric acid solution to control the concentration of halloysite nanotubes at 0.02 g / mL. The mixture was stirred at 70℃ for 4 hours, centrifuged, and the precipitate was washed until neutral. It was then dried at 90℃ for 12 hours to obtain pretreated halloysite nanotubes. The inner diameter of the pretreated halloysite nanotubes was found to be approximately 25 nm. S1-1. Take 1g of pretreated halloysite nanotubes and 1.85mL of tetraethyl orthosilicate and add them to 100mL of ethanol. Disperse them by ultrasonication for 1h to obtain solution A. Take 1.2g of cetyltrimethylammonium bromide (CTAB) and 2mL of 25wt% ammonia water and add them to 20mL of deionized water. Stir for 5min to obtain solution B. S1-2. Add solution B dropwise to solution A under stirring. After the addition is complete, stir the reaction at 1000 rpm for 1 h. Then transfer the product to a reaction vessel and react at 100 °C for 12 h. Centrifuge, wash the precipitate with deionized water, dry it at 90 °C for 8 h, and then calcine it at 550 °C for 4 h to obtain the mesoporous silica-haloite nanotube composite, i.e., the first composite. S2. Assemble the first composite with mica sheets to obtain the second composite: S2-1. Add 1g of mica sheet to 50mL of 10wt% hydrochloric acid solution, sonicate at 50℃ for 6h, centrifuge, wash the precipitate with deionized water until neutral, and then dry at 110℃ for 12h to obtain pretreated mica sheet. S2-2. Add 1g of pretreated mica sheet and 0.65g of cerium chloride to 100mL of deionized water and sonicate for 1h to obtain dispersion 1; add 1.5g of the first complex to a mixture of 120mL of ethanol and deionized water in a volume ratio of 1:1 and sonicate for 1h to obtain dispersion 2. S2-3. Under stirring, add dispersion 2 to dispersion 1, sonicate for 1.5 h, then add 20 wt% ammonia water to adjust the pH to 9, stir at 1200 rpm for 1 h, transfer the obtained product to a reaction vessel, react at 160℃ for 24 h, cool to room temperature, centrifuge, wash the precipitate with deionized water, vacuum dry at 90℃ for 24 h, grind to obtain mesoporous silica-haloite nanotube-mica sheet composite, i.e., the second composite. S3. After surface modification of the second composite, an antioxidant is loaded to obtain an antioxidant composite: S3-1. Add 2g of the second complex to a mixture of 150mL of deionized water and ethanol in a volume ratio of 1:7, sonicate for 1h, add 0.8g of silane coupling agent KH570 under stirring, stir and reflux at 75℃ for 6h, centrifuge, wash the precipitate with ethanol, and vacuum dry at 90℃ for 12h to obtain the modified second complex. S3-2. Add 1g of the modified second complex to 50mL of cyclohexane solution with a concentration of 10% antioxidant 168, sonicate for 2h, then let stand for 6h at 50℃ and -0.1MPa vacuum, centrifuge, wash the precipitate with cyclohexane and ethanol in sequence, and dry under vacuum at 100℃ for 12h to obtain the antioxidant complex. S4. Grafting a binary copolymer (methyl methacrylate-glycidyl methacrylate copolymer) onto the antioxidant complex yields an anti-aging-barrier-reinforcing filler: 1.5g of antioxidant multi-component composite particles were added to 50mL of toluene and ultrasonically dispersed for 45min to obtain mixture A. 2.5g of glycidyl methacrylate, 1.8g of methyl methacrylate, 0.2g of emulsifier OP-10, and 0.1g of benzoyl peroxide were added to 50mL of toluene and stirred for 15min. This mixture was then added to mixture A, and the mixture was stirred under nitrogen for 60min. The temperature was raised to 75℃, and the reaction was carried out under nitrogen protection for 10h. The mixture was cooled to room temperature, filtered, and the solid product was washed sequentially with toluene and ethanol. The product was then vacuum dried at 90℃ for 12h to obtain the anti-aging-barrier-reinforcing filler.

[0058] Example 2 The only difference between this example and Example 1 is that the amount of halloysite nanotubes added in step S1-1 of this example is modified to 1.25g.

[0059] Example 3 The only difference between this example and Example 1 is that the amount of halloysite nanotubes added in step S1-1 of this example is modified to 0.75g.

[0060] Comparative Example 1: The only difference between this example and Example 1 is that the raw materials for preparing the electrolyte-resistant and anti-aging composite current collector base film include, by weight, 90 parts of PET resin, 10 parts of PEN resin, 3 parts of coupling agent, 1 part of lubricant, and 1.2 parts of antioxidant 168.

[0061] Comparative Example 2: The only difference between this example and Example 1 is that: The anti-aging-barrier-reinforced filler in this example was prepared through the following steps: S1. Halloysite nanotubes are pretreated by the following steps to remove impurities and expand pores; the specific steps are the same as steps S1-0 in Example 1; the pretreated halloysite nanotubes are used as the first composite. S2. Assemble the first composite with mica sheets to obtain the second composite; the specific steps are the same as in Example 1. Steps S3 and S4 are the same as in Example 1.

[0062] Comparative Example 3: The only difference between this example and Example 1 is that: The anti-aging-barrier-reinforced filler in this example was prepared through the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite material. The specific steps were the same as in Example 1. S2. Add 1g of mica sheet to 50mL of 10wt% hydrochloric acid solution, sonicate at 50℃ for 6h, centrifuge, wash the precipitate with deionized water until neutral, and then dry at 110℃ for 12h to obtain pretreated mica sheet. S3. After surface modification of the first composite, an antioxidant is loaded to obtain an antioxidant composite: S3-1. Add 2g of the first complex to a mixture of 150mL of deionized water and ethanol in a volume ratio of 1:7, sonicate for 1h, add 0.8g of silane coupling agent KH570 under stirring, stir and reflux at 75℃ for 6h, centrifuge, wash the precipitate with ethanol, and vacuum dry at 90℃ for 12h to obtain the modified first complex. S3-2. Add 1g of the modified first complex to 50mL of cyclohexane solution of antioxidant 168 with a concentration of 10%, disperse by ultrasonication for 2h, then let stand for 6h under vacuum conditions of 50℃ and -0.1MPa, centrifuge, wash the precipitate with cyclohexane and ethanol in sequence, and dry under vacuum at 100℃ for 12h to obtain the antioxidant complex. S4. Surface modification of the pretreated mica sheets to obtain modified mica sheets: 2g of pretreated mica flakes were added to a mixture of 150mL of deionized water and ethanol in a volume ratio of 1:7, and ultrasonically dispersed for 1h. 0.8g of silane coupling agent KH570 was added under stirring, and the mixture was stirred and refluxed at 75℃ for 6h. After centrifugation, the precipitate was washed with ethanol and vacuum dried at 90℃ for 12h to obtain modified mica flakes. S5. Grafting polymer onto the antioxidant complex after blending it with modified mica sheets: 0.6 g of modified mica flakes and 0.9 g of antioxidant complex were added to 50 mL of toluene and ultrasonically dispersed for 45 min to obtain mixture A. 2.5 g of glycidyl methacrylate, 1.8 g of methyl methacrylate, 0.2 g of emulsifier OP-10, and 0.1 g of benzoyl peroxide were added to 50 mL of toluene and stirred for 15 min. This mixture was then added to mixture A, and the mixture was stirred under nitrogen for 60 min. The temperature was raised to 75 °C, and the mixture was stirred and reacted under nitrogen protection for 10 h. After cooling to room temperature, the mixture was filtered. The solid product was washed sequentially with toluene and ethanol, and then vacuum dried at 90 °C for 12 h to obtain the anti-aging-barrier-reinforcing filler.

[0063] Comparative Example 4: The only difference between this example and Example 1 is that: The raw materials for preparing the electrolyte-resistant and anti-aging composite current collector base film in this example include, by weight, 90 parts of PET resin, 10 parts of PEN resin, 3 parts of coupling agent, 1 part of lubricant, and 4.6 parts of antioxidant complex.

[0064] The preparation method of the antioxidant complex is the same as in Example 1.

[0065] 1. Controllable adjustment test of sustained-release performance Test method: Add 150 mL of cyclohexane to a flask, then add 3 g of antioxidant complex, sonicate for 20 min and seal. Every 6 h or 12 h, open the lid and stir to detect the concentration of antioxidant 168 in the mixed solution (using UV-Vis spectrophotometry). Calculate the cumulative percentage of antioxidant 168 released at different release times (cumulative mass percentage of released amount to total load) and plot the release curve.

[0066] The antioxidant complex was prepared according to the steps of Example 1. The proportion of mesoporous silica in the prepared mesoporous silica-haloyrite nanotube complex was controlled by changing the amount of pretreated halloyrite nanotubes added in step S1-1. The amount of pretreated halloyrite nanotubes added in the experimental group was 0.75g, 1g and 1.25g respectively. The resulting antioxidant complexes were named antioxidant complex-1, antioxidant complex-2 and antioxidant complex-3 respectively.

[0067] A control group was also set up, denoted as antioxidant complex-4, which was prepared as follows: The pretreated halloysite nanotubes prepared in step S1 of Example 1 were used to replace the second composite in Example 1. Then, the antioxidant composite was prepared according to step S3 of Example 1, and it was denoted as antioxidant composite-4 (i.e., equivalent to the addition of mesoporous silica).

[0068] The release curves of each antioxidant complex were obtained using the methods described above.

[0069] The greater the amount of pretreated halloysite nanotubes added, the smaller the proportion of mesoporous silica. That is, the proportion of mesoporous silica in antioxidant complex-1, antioxidant complex-2, antioxidant complex-3, and antioxidant complex-4 gradually decreases.

[0070] Test results are as follows Figure 1 As shown, it can be seen that as the proportion of mesoporous silica gradually decreases, the sustained release rate of antioxidants provided by antioxidant complex-1, antioxidant complex-2, antioxidant complex-3, and antioxidant complex-4 gradually increases, indicating that the sustained release rate can be controlled by adjusting the proportion of mesoporous silica in the mesoporous silica-haloite nanotube complex.

[0071] 2. Figure 2The XRD pattern of the second composite prepared in Example 1 shows that the broad peak near 2θ=23.2° is the diffraction peak of silica, the diffraction peaks near 2θ≈17.7°, 26.8°, 45.5° are the diffraction peaks of mica sheets, the diffraction peaks near 2θ=12.1°, 20.0° are the diffraction peaks of halloysite nanotubes, and the diffraction peaks near 2θ=28.5°, 33.2°, 47.4°, 56.5° are the diffraction peaks of cerium oxide. The results show that the present invention successfully assembled the mesoporous silica-haloysite nanotube composite with mica sheets to obtain the mesoporous silica-haloysite nanotube-mica sheet composite.

[0072] 3. Base film performance testing (1) Tensile strength test Referring to ASTM D882-12, "Standard Test Methods for Tensile Properties of Thin Films and Sheets," the tensile breaking strength of the composite current collector base films prepared in the examples and comparative examples was tested using a universal tensile testing machine. The test results are shown in Table 1 below. Figure 3 As shown: Table 1

[0073] The test results show that the composite current collector base films prepared in Examples 1-3 have high tensile strength, while Comparative Examples 1-4 all showed varying degrees of decrease. Comparative Example 1, which did not add anti-aging-barrier reinforcing filler, showed the most significant decrease in tensile strength. The results of Comparative Example 2 indicate that the mesoporous silica deposited in the anti-aging-barrier reinforcing filler has a certain effect on improving tensile strength. The decrease in tensile strength in Comparative Example 3 is due to the failure to assemble the mica sheets and mesoporous silica-halothite nanotube composite into ternary composite particles, resulting in a reduced effect on improving the tensile strength of the base film. Comparative Example 4 is due to the failure to use methyl methacrylate-glycidyl methacrylate copolymer for grafting, which significantly reduced the dispersion performance of the anti-aging-barrier reinforcing filler.

[0074] (2) Heat and oxygen aging resistance test Test Method: The composite current collector base films prepared in the examples and comparative examples were placed in an aging chamber and subjected to accelerated aging tests in hot air at 85°C for 150 hours and 400 hours, respectively. After cooling to room temperature, the longitudinal tensile strength was measured again. The retention rate of longitudinal tensile strength (tensile strength after aging / tensile strength before aging) was used to measure the heat aging resistance performance. The higher the value, the better the heat aging resistance. The test results are shown in Table 2 below. Figure 4 As shown: Table 2

[0075] 1. According to the test results, in the early aging stage (150 hours of aging), the tensile strength retention rates of Comparative Example 2, Example 2, Example 1, and Example 3 decreased sequentially (indicating that the antioxidant performance weakened sequentially); in the later aging stage (400 hours of aging), the tensile strength retention rates of Comparative Example 2, Example 2, Example 1, and Example 3 increased sequentially (indicating that the antioxidant performance strengthened sequentially). The results were analyzed as follows: The proportion of mesoporous silica in the anti-aging-barrier reinforcing fillers of Comparative Example 2, Example 2, Example 1, and Example 3 increases sequentially, so the slow release rate of the antioxidant decreases sequentially. Therefore, the antioxidant concentration that can be provided in the early stage of aging decreases sequentially, resulting in a sequential decrease in tensile strength retention rate. However, in the later stage of aging, as the antioxidant is gradually consumed and the slow release rate is relatively lower, the continuous anti-aging effect that can be provided in the later stage of aging is stronger. Therefore, the degree of decrease in tensile strength decreases sequentially, that is, the tensile strength retention rate increases sequentially.

[0076] 2. Analysis of other comparative examples: In Comparative Example 1, the antioxidant was directly added to the raw material, which did not have a slow-release effect, resulting in a significant decrease in its antioxidant performance, especially its long-term antioxidant performance; the changes in Comparative Example 3 were not obvious; in Comparative Example 4, the grafting of methyl methacrylate-glycidyl methacrylate copolymer was not used, which made it impossible for the anti-aging-barrier reinforcing filler to be evenly dispersed, greatly reducing its effect on improving aging resistance, and thus significantly reducing the tensile strength retention rate.

[0077] (3) Heat shrinkage rate test The thermal shrinkage rate of the composite current collector base film prepared according to the ASTM D2732 test examples and comparative examples at 150°C was measured; the test results are shown in Table 3 below. Figure 5 As shown: Table 3

[0078] The test results show that the composite current collector base film prepared in Examples 1-3 has excellent heat resistance, while the heat resistance of Comparative Examples 1-4 decreased to varying degrees.

[0079] 4. Application performance testing A copper layer with a thickness of 0.85 μm was electroplated onto the upper and lower surfaces of the composite current collector substrate film prepared in the examples and comparative examples using an electroplating process to prepare the composite current collector. The specific process was as follows: the substrate film was placed in an electroplating solution and electroplated at a temperature of 25°C and a current intensity of 2A, with air continuously injected into the electroplating solution during the electroplating process. The electroplating solution contained 160 g / L copper sulfate, 120 g / L sulfuric acid, and 40 mg / L hydrochloric acid. Then, the composite current collector was subjected to an adhesion test. The test method was the cross-cut adhesion test according to standard GB9286-2021: the test film was divided into 400 1x1 mm squares, and then the film was tightly adhered with 3M tape. The tape was then vertically peeled off, and the detachment of the copper layer in each square was observed. The cross-cut adhesion rate was calculated. Three sets of tests were performed for each sample, and the average value was taken as the result. The lower the adhesion rate, the stronger the adhesion. The test results are shown in Table 4 below. Figure 6 As shown: Table 4

[0080] The test results show that the base film prepared in Examples 1-3 has good bonding strength with the copper layer, while Comparative Examples 1-4 show varying degrees of decrease.

[0081] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. An electrolyte-resistant and anti-aging composite current collector base film, characterized in that, The raw materials for its preparation include, by weight: 80-100 parts of PET resin, 7-22 parts of PEN resin, 2-4.5 parts of coupling agent, 0.5-2 parts of lubricant, and 14-25 parts of anti-aging-barrier reinforcing filler. The anti-aging-barrier-reinforced filler is prepared through the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite. S2. Assemble the first composite with mica sheets to obtain the second composite; S3. After surface modification of the second composite, an antioxidant is loaded to obtain an antioxidant composite. S4. Grafting a binary copolymer onto an antioxidant composite yields an anti-aging-barrier-reinforced filler.

2. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 1, characterized in that, The anti-aging-barrier-reinforced filler is prepared through the following steps: S1. Mesoporous silica was synthesized in situ on halloysite nanotubes to obtain the first composite: S1-1. Halloysite nanotubes and tetraethyl orthosilicate are dispersed in ethanol to obtain solution A; CTAB and ammonia are added to deionized water to obtain solution B. S1-2. Add solution B dropwise to solution A, stir to react, then transfer the product to a reaction vessel and react at 90-120℃ for 6-24 hours. Centrifuge, wash the precipitate, dry and calcine to obtain the first complex. S2. Assemble the first composite with mica sheets to obtain the second composite: S2-1. Add mica sheets to hydrochloric acid solution, heat and sonicate, centrifuge, wash the precipitate until neutral, and dry to obtain pretreated mica sheets; S2-2. Pretreated mica flakes and cerium chloride are dispersed in deionized water to obtain dispersion 1; the first complex is dispersed in a mixture of ethanol and deionized water to obtain dispersion 2. S2-3. Add dispersion 2 to dispersion 1, ultrasonically disperse, adjust pH to alkaline, stir, transfer the obtained product to a reaction vessel, react at 140-180℃ for 12-48h, centrifuge, precipitate, wash, dry, grind, and obtain the second complex. S3. After surface modification of the second composite, an antioxidant is loaded to obtain an antioxidant composite: S3-1. The second complex is dispersed in a mixture of deionized water and ethanol, silane coupling agent KH570 is added, the mixture is heated and stirred under reflux, centrifuged, the precipitate is washed and dried to obtain the modified second complex. S3-2, Add antioxidant to the modified second complex. In solution, after ultrasonic dispersion The mixture was allowed to stand under vacuum, centrifuged, the precipitate was washed, and dried to obtain the antioxidant complex. S4. Grafting a binary copolymer onto the antioxidant complex yields an anti-aging-barrier-reinforced filler: Antioxidant multi-component composite particles were dispersed in toluene to obtain mixture A; glycidyl methacrylate, methyl methacrylate, emulsifier OP-10, and benzoyl peroxide were added to toluene to obtain mixture B. Mixture B was added to mixture A, nitrogen gas was passed through and stirred, the temperature was raised, and the reaction was carried out under nitrogen protection. After the reaction was completed, the mixture was filtered, and the solid product was washed and dried to obtain anti-aging-barrier reinforcing filler.

3. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 2, characterized in that, The halloysite nanotubes in step S1 are pretreated using the following method: Halloysite nanotubes were calcined, cooled, and then added to a hydrochloric acid solution. The mixture was heated and stirred, centrifuged, and the precipitate was washed until neutral. The precipitate was then dried to complete the pretreatment.

4. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 2, characterized in that, Antioxidant in step S3 Antioxidants in solution are selected from At least one of antioxidant 168, antioxidant 1010, antioxidant 1076, antioxidant 330, 1076, antioxidant 626, antioxidant 618, and antioxidant PL-440.

5. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 2, characterized in that, Step S1 is as follows: S1-0. Calcine halloysite nanotubes at 450-600℃ for 2-8 hours, cool to room temperature, and add to a hydrochloric acid solution with a concentration of 1-4 mol / L. Control the concentration of halloysite nanotubes to 0.01-0.05 g / mL, stir at 60-80℃ for 2-8 hours, centrifuge, wash the precipitate until neutral, and dry to complete the pretreatment of halloysite nanotubes. S1-1: Take 0.5-2g of pretreated halloysite nanotubes and 0.8-2mL of tetraethyl orthosilicate and add them to 50-200mL of ethanol. Disperse by ultrasonication for 0.5-2h to obtain solution A; Take 0.6-2.4g of CTAB and 1-4mL of 15-28wt% ammonia solution and add them to 10-40mL of deionized water. Stir for 2-10min to obtain solution B. S1-2. Add solution B dropwise to solution A with stirring. After the addition is complete, stir the reaction for 0.5-2 hours. Then transfer the product to a reaction vessel and react at 90-120℃ for 6-24 hours. Centrifuge, wash the precipitate with deionized water, dry it at 70-100℃ for 4-16 hours, and then calcine it at 500-600℃ for 2-4 hours to obtain the first complex.

6. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 2, characterized in that, Step S2 is as follows: S2-1. Add 0.5-2g of mica sheets to 25-100mL of 5-20wt% hydrochloric acid solution, sonicate at 40-60℃ for 3-12h, centrifuge, wash the precipitate with deionized water until neutral, and then dry at 100-130℃ for 6-24h to obtain pretreated mica sheets. S2-2, Add 0.5-2g of pretreated mica sheets and 0.35-1.3g of cerium chloride to 50-200mL of deionized water, and ultrasonically disperse for 0.5-2h to obtain dispersion 1; Add 0.75-3g of the first complex to a mixture of 60-200mL of ethanol and deionized water in a volume ratio of 1:1, and ultrasonically disperse for 0.5-2h to obtain dispersion 2; S2-3. Add dispersion 2 to dispersion 1 under stirring, and sonicate for 1-3 hours. Then, add 10-25 wt% ammonia water to adjust the pH to 8-10, stir for 0.5-2 hours, transfer the obtained product to a reaction vessel, react at 140-180℃ for 12-48 hours, cool to room temperature, centrifuge, wash the precipitate with deionized water, vacuum dry at 80-100℃ for 12-36 hours, grind, and obtain the second complex.

7. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 2, characterized in that, Step S3 is as follows: S3-1. Add 1-4g of the second complex to a mixture of 75-300mL of deionized water and ethanol in a volume ratio of 1:7, and sonicate for 0.5-2h. Add 0.4-1.6g of silane coupling agent KH570 while stirring, and reflux at 65-80℃ for 3-12h. Centrifuge, wash the precipitate with ethanol, and vacuum dry at 70-100℃ for 6-24h to obtain the modified second complex. S3-2, Add 0.5-2g of the modified second complex to 25-100mL of antioxidant 168 at a concentration of 4-15%. cyclohexane solution Disperse by ultrasound for 1-4 hours, then at 40-60℃. Let stand under a vacuum of -0.1 MPa for 3-12 hours, centrifuge, and use the precipitate. Cyclohexane and ethanol in sequence The mixture was rinsed and then vacuum dried at 90-100℃ for 6-24 hours to obtain the antioxidant complex.

8. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 2, characterized in that, Step S4 is as follows: Add 0.5-3g of antioxidant multi-component composite particles to 25-100mL of toluene and ultrasonically disperse for 30-90min to obtain mixture A. Add 1.25-5g of glycidyl methacrylate, 0.9-3.6g of methyl methacrylate, 0.1-0.4g of emulsifier OP-10, and 0.05-0.2g of benzoyl peroxide to 25-100mL of toluene and stir for 5-30min. Then add the mixture to mixture A, purge with nitrogen and stir for 30-90min. Heat to 70-85℃ and stir under nitrogen protection for 5-20h. Cool to room temperature, filter, wash the solid product with toluene and ethanol sequentially, and vacuum dry at 70-95℃ for 6-24h to obtain the anti-aging-barrier-reinforcing filler.

9. The electrolyte-resistant and anti-aging composite current collector substrate film according to claim 1, characterized in that, The lubricant is selected from at least one of N,N-ethylene bis-stearamide, pentaerythritol stearate, calcium stearate, and zinc stearate; The coupling agent is selected from at least one of silane coupling agent A-151, silane coupling agent A-171, silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

10. The electrolyte-resistant and anti-aging composite current collector substrate film according to any one of claims 1-9, characterized in that, It is prepared through the following steps: PET resin, PEN resin, coupling agent, lubricant, and anti-aging-barrier reinforcing filler are mixed evenly according to the weight ratio. The resulting mixture is melt-extruded at 250-265℃, cooled, cast, and biaxially stretched to obtain an electrolyte-resistant and anti-aging composite current collector base film.

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