Anti-aging fumed silica-silicon carbide-glass fiber filament power battery packaging nanometer plate and preparation method thereof

Abstract

This invention discloses an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate and its preparation method, relating to the field of power battery encapsulation materials technology. The nanoplate comprises 45-55 parts of epoxy resin matrix, 42-61 parts of acid anhydride curing agent, 4-8 parts of epoxy reactive diluent, 3-7 parts of toughening agent, 14-22 parts of inorganic flame retardant, 2-5 parts of flame retardant synergist, 0.2-0.6 parts of curing accelerator, 22-36 parts of anti-aging reinforcing agent, and 35-50 parts of glass fiber reinforcement. The anti-aging reinforcing agent consists of an aminated alkali-free E-glass pulverized fiber skeleton, mercaptoized β-silicon carbide nodes, and a partially grafted 4-amino-2,2,6,6-tetramethylpiperidine epoxide fumed silica bridging phase. It is prepared by dispersion, impregnation, lamination, and segmented hot pressing curing. The nanoplate possesses anti-aging, flame retardant, mechanical, and insulating properties.

Description

Technical Field

[0001] This invention relates to the field of composite material technology for power battery packaging, specifically to an anti-aging fumed silica-silicon carbide-glass fiber power battery packaging nanoplate and its preparation method. Background Technology

[0002] Power battery encapsulation plates must withstand assembly pre-tightening, vehicle vibration, and external impacts, while maintaining structural integrity and flame-retardant and heat-insulating capabilities under battery temperature rise or thermal runaway conditions. Epoxy resin and glass fiber composites are easy to mold, have high specific strength, and good insulation properties, making them suitable for battery casings, covers, and separators. However, bisphenol A type epoxy resins undergo oxidation, chain segment breakage, and changes in the cross-linking network under prolonged heating and aerobic environments. Moisture ingress can also cause plasticization and interfacial hydrolysis. Glass fiber and resin exhibit different thermal expansion behaviors, making the plates prone to microcracks, interfacial debonding, and interlayer damage under humid heat and temperature cycling. This reduces load-bearing capacity, and mechanical properties and dimensional stability gradually decline.

[0003] Current solutions typically incorporate glass fiber, fumed silica, silicon carbide, metal hydroxides, and flame retardant synergists into epoxy systems to achieve a balance of reinforcement, heat resistance, and flame retardancy. However, the coexistence of multiple inorganic particles with fibers can easily lead to agglomeration, and insufficient compatibility between the particle surface and the resin can result in porosity and weak interfaces. Increasing the amount of flame-retardant filler increases resin viscosity, making glass fiber impregnation and defoaming more difficult to control. Conventional anti-aging small molecules often exist in a physical blending manner, and may migrate or locally accumulate under heat, humidity, and long-term use conditions, making it difficult to continuously protect the resin matrix and fiber interface. Simply increasing the filler content cannot simultaneously solve the problems of flame retardancy, mechanical retention, and anti-aging, and may also cause embrittlement of the board, insufficient interlayer bonding, and performance fluctuations. Current technology still requires a method for preparing a power battery encapsulation nanoplate that can stably organize the interface between fumed silica, silicon carbide, and glass fiber while simultaneously achieving flame retardancy, reinforcement, and long-term anti-aging properties. Summary of the Invention

[0004] The purpose of this invention is to address the problems in existing power battery encapsulation composite plates, such as easy agglomeration of inorganic fillers, insufficient interfacial bonding between fillers and resin matrix and glass fiber reinforcement, insufficient stability of anti-aging components under long-term hot and humid environments, and difficulty in simultaneously achieving anti-aging performance, flame retardant performance and mechanical properties. This invention provides an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate with uniform inorganic component dispersion, stable interfacial bonding, and combined anti-aging performance, flame retardant performance and structural reinforcement effect, as well as its preparation method.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate, which is composed of the following components in parts by weight: 45-55 parts of epoxy resin matrix, 43-61 parts of acid anhydride curing agent, 4-8 parts of epoxy reactive diluent, 3-7 parts of toughening agent, 14-22 parts of inorganic flame retardant, 2-5 parts of flame retardant synergist, 0.2-0.6 parts of curing accelerator, 22-36 parts of anti-aging reinforcing agent, and 35-50 parts of glass fiber reinforcement; The ratio of the equivalent number of anhydride groups in the anhydride curing agent to the total equivalent number of epoxy groups in the epoxy resin matrix and the epoxy reactive diluent is 0.90-1.00:1; The anti-aging reinforcing agent comprises a reinforcing skeleton composed of ammoniated alkali-free E glass ground fibers, spaced-distributed mercapto-modified β-silicon carbide nodes, and an epoxidized fumed silica bridging phase located between the mercapto-modified β-silicon carbide nodes and the reinforcing skeleton. Part of the epoxy groups in the epoxidized fumed silica bridging phase undergo a ring-opening reaction with the primary amino group at the 4-position of 4-amino-2,2,6,6-tetramethylpiperidine, covalently bonding through CN bonds to form a β-hydroxy secondary amine structure, thus fixing the hindered piperidine structure on the fumed silica surface. Another part of the epoxy groups in the epoxidized fumed silica bridging phase undergoes a ring-opening reaction with the thiol groups on the surface of the thiolized β-silicon carbide node, covalently bonding through CS bonds to form a β-hydroxy thioether structure. The remaining epoxy groups undergo a ring-opening reaction with the amino groups on the surface of the aminated alkali-free E-glass ground fiber, covalently bonding through CN bonds to form a β-hydroxy secondary amine structure.

[0006] The mercaptolated β-silicon carbide nodes are covalently fixed to the surface of the reinforcing skeleton by the epoxy fumed silica bridging phase, and the epoxy fumed silica bridging phase is at least partially distributed between adjacent mercaptolated β-silicon carbide nodes to form an insulating gap region.

[0007] Furthermore, the anti-aging enhancer is composed of the following raw materials by weight: 38-46 parts of β-silicon carbide micro powder, 22-30 parts of alkali-free E glass ground fiber, 14-20 parts of hydrophilic fumed silica, 1.8-3.0 parts of 3-aminopropyltriethoxysilane, 1.5-2.5 parts of 3-mercaptopropyltrimethoxysilane, 5.0-7.0 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and 0.6-1.1 parts of 4-amino-2,2,6,6-tetramethylpiperidine.

[0008] Furthermore, the preparation method of the anti-aging enhancer includes the following steps: S1. The alkali-free E-glass ground fibers are added to a sodium hydroxide aqueous solution with a mass concentration of 2.0-3.0% (10-12 times their weight) and treated at 45-50°C for 20-30 min, then washed and dried. The 3-aminopropyltriethoxysilane is added to a mixture of anhydrous ethanol and deionized water, wherein the mass of anhydrous ethanol and deionized water is 3.5-4.5 times and 0.35-0.50 times the mass of the alkali-free E-glass ground fibers, respectively. The pH is adjusted to 4.5-5.0 using a 10% acetic acid aqueous solution, and hydrolyzed at 25-30°C for 25-35 min. The alkali-treated alkali-free E-glass ground fibers are then added, and the reaction is carried out at 55-60°C for 120-150 min. The mixture is filtered, washed, and vacuum dried to obtain an aminated glass fiber skeleton.

[0009] S2. Add the β-silicon carbide micro powder to a 6-8% hydrogen peroxide aqueous solution at 3-4 times its mass. Add 2-4 parts of anhydrous sodium carbonate per 100 parts of β-silicon carbide micro powder, adjust the pH to 9.5-10.5, and treat at 65-72℃ for 75-105 minutes. Wash and dry. Under nitrogen protection, add the 3-mercaptopropyltrimethoxysilane to a mixture of anhydrous ethanol and deionized water. Anhydrous ethanol and deionized water were added at 3.0-3.8 times and 0.30-0.45 times the mass of β-silicon carbide micropowder, respectively. The pH was adjusted to 4.2-4.8 using a 10% acetic acid aqueous solution. The mixture was hydrolyzed at 25-30℃ for 25-35 min. The oxidized and activated β-silicon carbide micropowder was then added, and the mixture was reacted at 50-56℃ for 120-150 min. The mixture was then filtered, washed, and vacuum dried to obtain mercapto-modified silicon carbide nodes.

[0010] S3. Disperse the hydrophilic fumed silica in anhydrous ethanol and deionized water, wherein the mass of anhydrous ethanol and deionized water is 3.5-4.5 times and 0.35-0.50 times the mass of the hydrophilic fumed silica, respectively; add the γ-glycidoxypropyltrimethoxysilane to the mixture of anhydrous ethanol and deionized water, wherein the mass of anhydrous ethanol and deionized water is 1.8-2.4 times and 0.18-0.30 times the mass of the hydrophilic fumed silica, respectively; adjust the pH to 4.3-4.8 using a 10% aqueous acetic acid solution; and hydrolyze at 25-30°C for 25-35 minutes. The obtained hydrolysate was added to a hydrophilic fumed silica dispersion and reacted at 50-56℃ for 120-180 min. After filtration, washing, and drying, epoxidized fumed silica was obtained. Under nitrogen protection, the epoxidized fumed silica was dispersed in anhydrous isopropanol at 3.5-4.5 times its mass. The 2,2,6,6-tetramethylpiperidineamine was added at a rate of 0.10-0.25 mL / min per 100 g of epoxidized fumed silica. After reacting at 35-42℃ for 60-90 min, the mixture was filtered, washed, and vacuum dried to obtain a hindered amine-grafted epoxidized fumed silica bridge.

[0011] S4. Under nitrogen protection, the mercaptolated silicon carbide nodes are dispersed in anhydrous isopropanol to prepare a dispersion with a solid content of 12-18 wt%. The hindered amine-grafted epoxidized fumed silica bridge is added, and 0.15-0.30 parts of triethylamine are added based on 100 parts of the total mass of the two. The reaction is carried out at 45-52℃ for 120-180 min to obtain a silicon carbide-fumed silica node composite. The aminated glass fiber skeleton is dispersed in anhydrous isopropanol at 8-12 times its mass. The silicon carbide-fumed silica node composite is added at a dry basis rate of 0.5-1.0 g / min per 100 g of aminated glass fiber skeleton. The reaction is carried out at 65-72℃ for 150-210 min, and then kept at 85-90℃ for 60-90 min to obtain a sulfide-hindered amine three-phase bridged composite precursor.

[0012] S5. Filter the sulfide-hindered amine three-phase bridging composite precursor, wash it sequentially with 2-3 times its mass of anhydrous isopropanol and 2-3 times its mass of anhydrous ethanol based on the dry weight of the precursor, dry it for 8-10 hours at 70-80℃ and vacuum gauge pressure of -0.095 to -0.080 MPa, then heat it at 105-115℃ for 2-3 hours under nitrogen protection, depolymerize it at a speed not exceeding 800 r / min for 1-2 minutes, pass it through a 60-mesh sieve and collect the particles trapped on the 180-mesh sieve to obtain the anti-aging enhancer.

[0013] The anti-aging reinforcing agent uses aminated alkali-free E-glass ground fibers as a one-dimensional load-bearing skeleton, with thiolized β-silicon carbide distributed on its surface as spacer nodes, and epoxidized fumed silica located between them. Some epoxy groups on the surface of the fumed silica ring-open with the primary amino group at the 4-position of 4-amino-2,2,6,6-tetramethylpiperidine, covalently bonding through CN bonds to form a β-hydroxy secondary amine structure, thus fixing the hindered piperidine structure to the particle surface. Another portion of the epoxy groups reacts with the thiol groups on the silicon carbide surface, covalently bonding through CS bonds to form a β-hydroxy sulfide structure. The remaining epoxy groups then react with the amino groups on the glass fiber surface, fixing the silicon carbide nodes to the glass fiber skeleton through CN bonds. This structure restricts the migration and aggregation of silicon carbide and fumed silica in the resin, and the insulating spacer region formed by the fumed silica reduces direct contact between silicon carbide particles. The glass fiber bears the load transfer, the silicon carbide improves rigidity, heat resistance, and crack resistance, and the fumed silica improves particle spacing and interfacial contact. Nitrogen atoms of the hindered piperidine ring can form nitrogen oxide radical reactive intermediates in a thermo-oxidative environment, which participate in capturing alkyl radicals and peroxy radicals and undergo regeneration cycles, thereby slowing down the degradation of epoxy matrix and fiber interface properties; covalent fixation can reduce the migration and local enrichment of anti-aging structures, and alleviate interface debonding, microcracks and mechanical property degradation caused by humid heat and temperature cycling.

[0014] Furthermore, the epoxy resin matrix is ​​bisphenol A type epoxy resin E-51.

[0015] Furthermore, the anhydride curing agent is methylhexahydrophthalic anhydride.

[0016] Furthermore, the epoxy-based reactive diluent is 1,4-butanediol diglycidyl ether.

[0017] Furthermore, the toughening agent is a carboxyl-terminated liquid nitrile rubber.

[0018] Furthermore, the inorganic flame retardant is selected from aluminum hydroxide and magnesium hydroxide.

[0019] Furthermore, the flame retardant synergist is one of zinc borate and zinc hydroxystannate.

[0020] Furthermore, the curing accelerator is selected from 2-ethyl-4-methylimidazole and 1-benzyl-2-methylimidazole.

[0021] Furthermore, the fiberglass reinforcement is a multiaxial stitch-woven composite felt.

[0022] A method for preparing an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate includes the following steps: B1. The anti-aging reinforcing agent, inorganic flame retardant, flame retardant synergist and glass fiber reinforcement are pre-dried; the epoxy resin matrix and toughening agent are mixed and heated and stirred. After the toughening agent is evenly dispersed, the epoxy reactive diluent is added, and dehydration and degassing are carried out under vacuum conditions to obtain resin premix.

[0023] B2. Under stirring conditions, the dried inorganic flame retardant and flame retardant synergist are sequentially added to the resin premix and dispersed by high-speed shearing; after reducing the stirring speed, the anti-aging reinforcing agent is added in batches to ensure that the anti-aging reinforcing agent is uniformly wetted and dispersed in the resin premix; the system temperature is reduced, the acid anhydride curing agent and curing accelerator are added, and after mixing evenly, vacuum degassing is performed to obtain the inorganic functional filler dispersion resin.

[0024] B3. The inorganic functional filler dispersion resin is applied to the surface of the pre-dried glass fiber reinforcement, so that the inorganic functional filler dispersion resin is impregnated into the fiber gaps of the glass fiber reinforcement; the impregnated glass fiber reinforcement is scraped, vacuum degassing and laminated to obtain a preformed board.

[0025] B4. The preformed plate is placed in a hot press mold and subjected to low-temperature flow venting, medium-temperature pre-curing and high-temperature complete curing in sequence. After curing, pressure is maintained and the plate is cooled. After demolding, post-curing and cutting are performed to obtain the anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate.

[0026] Furthermore, in B1, the epoxy resin matrix and toughening agent are mixed at 65-75°C and 500-700 r / min for 30-45 min, and after adding the epoxy reactive diluent, the mixture is dehydrated and degassed for 10-20 min under a vacuum gauge pressure of -0.095 to -0.085 MPa.

[0027] Further, in step B2, after adding the inorganic flame retardant and flame retardant synergist to the resin premix, it is sheared and dispersed at 2200-3200 r / min for 10-20 min. After reducing the rotation speed to 600-900 r / min, the anti-aging reinforcing agent is added in 3-5 batches and dispersed for another 20-30 min. The system temperature is then reduced to 30-35℃, and the acid anhydride curing agent and curing accelerator are added. The mixture is then mixed at 300-500 r / min for 10-15 min, and then degassed at a vacuum gauge pressure of -0.095-0.085 MPa for 8-15 min.

[0028] Furthermore, in step B3, the impregnated glass fiber reinforcement is placed under a vacuum gauge pressure of -0.095 to -0.085 MPa for 15-30 minutes to degas the material, and the mass percentage of the continuous resin phase in the laminated preform is controlled to be 45-58%; the continuous resin phase is composed of the epoxy resin matrix, anhydride curing agent, epoxy reactive diluent, toughening agent and curing accelerator.

[0029] Furthermore, in B4, the segmented hot-press curing sequentially includes: holding pressure at 80-90℃ and 1-2MPa for 20-30 minutes, holding pressure at 120-135℃ and 3-5MPa for 40-60 minutes, and holding pressure at 155-170℃ and 5-8MPa for 60-90 minutes; after high-temperature curing, cooling to no higher than 60℃ while maintaining a pressure of 5-8MPa, and then post-curing at 175-185℃ for 2-3 hours after demolding.

[0030] The anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate of this invention uses epoxy resin and anhydride curing agent to form a continuous matrix. Epoxy-based reactive diluents reduce the viscosity of the mixture, allowing the resin to penetrate the fiber gaps of the multi-axial stitch-woven composite felt. A curing accelerator regulates the curing reaction process. Segmented hot pressing ensures resin flow, degassing, wetting, and curing are seamlessly connected, reducing porosity and localized glue defects. The glass fiber reinforcement bears tensile, bending, and interlaminar loads. Carboxyl-terminated liquid nitrile rubber mitigates curing shrinkage and stress concentration caused by external forces, maintaining structural continuity under load and temperature changes. Aluminum hydroxide or magnesium hydroxide absorbs heat and releases moisture upon thermal decomposition. Zinc borate or zinc hydroxystannate participates in the formation of the surface barrier layer, slowing the transfer of heat and combustible decomposition products. In the anti-aging reinforcing agent, the glass fiber skeleton, silicon carbide nodes, and fumed silica bridging phase are fixed by predetermined chemical bonds, limiting the migration and aggregation of inorganic particles and enhancing their contact with the resin matrix. The hindered amine structure captures free radicals generated during aging, mitigating oxidative damage at the epoxy matrix and fiber interface. The spacer effect of fumed silica reduces direct contact with silicon carbide, while silicon carbide provides rigid support and inhibits crack propagation, thus integrating flame retardancy, load-bearing capacity, and anti-aging effects into a single sheet material structure.

[0031] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention fixes the glass fiber skeleton, silicon carbide nodes and fumed silica bridging phase in the same structure, which can reduce the migration and agglomeration of inorganic particles and improve resin wetting and interfacial bonding.

[0032] 2. This invention fixes the hindered amine structure onto the surface of fumed silica with chemical bonds, which can slow down the aging of epoxy matrix and fiber interface under thermo-oxidative and humid conditions, thus maintaining stable mechanical and insulation properties.

[0033] 3. This invention utilizes silicon carbide, glass fiber reinforcement, inorganic flame retardant, and flame retardant synergist to provide reinforcement, heat resistance, and barrier properties, enabling the board to achieve a balance of bending performance, flame retardancy retention, and hygrothermal stability. Attached Figure Description

[0034] Figure 1 SEM image of the anti-aging enhancer obtained in Example 1. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. 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.

[0036] Preparation Example 1: Preparation of anti-aging enhancers: 1. Raw material composition: β-Silicon carbide micro powder: 42.0 parts; Alkali-free E-glass ground fiber: 26.0 parts; Hydrophilic fumed silica: 17.0 parts; 3-Aminopropyltriethoxysilane: 2.4 parts; 3-Mercaptopropyltrimethoxysilane: 2.0 parts; γ-Glycidyl etheroxypropyltrimethoxysilane: 6.0 parts; 4-Amino-2,2,6,6-Tetramethylpiperidine: 0.8 parts.

[0037] The β-silicon carbide micro powder was purchased from Guangzhou Hongwu Materials Technology Co., Ltd., item number: D505, with a purity of 99% and a particle size of 1-2μm.

[0038] The alkali-free E-glass shredded fiber was purchased from Chongqing International Composite Materials Co., Ltd., item number: EMG11-100, fiber diameter: 11µm, average fiber length: 100µm.

[0039] The hydrophilic fumed silica was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., item number: S818464, with a specific surface area of ​​200 m². 2 / g.

[0040] 2. Preparation method: S1. Add 286.0 parts by mass of a 2.5% sodium hydroxide aqueous solution to alkali-free E-glass ground fibers; the sodium hydroxide aqueous solution was prepared by 7.15 parts by mass of analytical grade sodium hydroxide and 278.85 parts by mass of deionized water. Heat the mixture to 48°C and stir at 380 r / min for 25 min under normal atmospheric pressure. After treatment, filter the mixture using a 200-mesh alkali-resistant filter cloth, and wash the filtered glass fibers three times sequentially with 260 parts, 260 parts, and 260 parts of deionized water, each wash lasting 5 min. The pH of the third wash solution is 7.0 ± 0.2. Dry the washed glass fibers at 80°C for 3.5 h to obtain alkali-treated alkali-free E-glass ground fibers. 3-Aminopropyltriethoxysilane was added to a mixture of 104.0 parts anhydrous ethanol and 10.92 parts deionized water, followed by the addition of 1.50 parts of a 10% (w / w) aqueous acetic acid solution at a rate of 0.10 parts / min. The aqueous acetic acid solution was prepared from 0.15 parts glacial acetic acid and 1.35 parts deionized water. The pH of the mixture was controlled at 4.8 ± 0.1, and hydrolysis was carried out at 28°C and 380 rpm for 30 min. Alkali-treated, alkali-free E-glass fibers were added to the hydrolysate over 10 min, and the temperature was raised to 58°C. The reaction was carried out at atmospheric pressure and 380 rpm for 135 min. After the reaction, the mixture was filtered through a 200-mesh solvent-resistant filter cloth, and the filtrate was washed twice, first with 78.0 parts and then with 78.0 parts anhydrous ethanol, each wash lasting 10 min. The washed product was dried at 80℃ and a vacuum gauge pressure of -0.090MPa for 5 hours to obtain 26.9 parts of aminated alkali-free E glass-ground fiber skeleton.

[0041] S2. Mix 34.30 parts by mass of a 30% hydrogen peroxide aqueous solution with 112.70 parts by mass of deionized water to prepare 147.0 parts by mass of a 7.0% hydrogen peroxide aqueous solution. Add β-silicon carbide micropowder to the hydrogen peroxide aqueous solution, and then add 1.26 parts by mass of anhydrous sodium carbonate to adjust the pH of the system to 10.0 ± 0.2. Heat the system to 69°C under normal atmospheric pressure and air atmosphere, stir at 600 r / min, and perform surface oxidation activation for 90 min. After treatment, filter through a 200-mesh filter cloth, and wash the filtrate three times with 420 parts, 420 parts, and 420 parts by mass of deionized water, each time for 5 min, to adjust the pH of the third washing solution to 7.0 ± 0.2. Dry the washed β-silicon carbide micropowder at 85°C for 4.5 h to obtain oxidized activated β-silicon carbide micropowder. Nitrogen gas was continuously introduced into a sealed reaction vessel at a flow rate of 0.50 L / min to maintain a slightly positive pressure nitrogen atmosphere. 3-Mercaptopropyltrimethoxysilane was added to a mixture of 142.80 parts anhydrous ethanol and 15.75 parts deionized water. Then, 1.80 parts of a 10% (w / w) aqueous acetic acid solution was added at a rate of 0.10 parts / min; the aqueous acetic acid solution was prepared from 0.18 parts glacial acetic acid and 1.62 parts deionized water. The pH of the system was controlled at 4.5 ± 0.1, and hydrolysis was carried out at 28 °C and 380 rpm for 30 min. Oxidized and activated β-silicon carbide micropowder was added to the hydrolysate over 15 min, and the temperature was raised to 53 °C. The reaction was carried out under nitrogen protection and at 580 rpm for 135 min. After the reaction, the mixture was filtered through a 200-mesh solvent-resistant filter cloth and rinsed twice, sequentially with 126.0 parts and 126.0 parts anhydrous ethanol, each rinsing for 10 min. The washed product was dried at 60°C and a vacuum gauge pressure of -0.090 MPa for 5 h to obtain 42.7 parts of mercapto-β-silicon carbide nodes.

[0042] S3. Hydrophilic fumed silica was added to a dispersion medium consisting of 68.0 parts anhydrous ethanol and 7.14 parts deionized water, and sheared and dispersed for 25 min under ambient air pressure, 25°C, and 3000 r / min to obtain a fumed silica dispersion. γ-glycidoxypropyltrimethoxysilane was added to a mixture consisting of 35.70 parts anhydrous ethanol and 4.08 parts deionized water, and 0.80 parts of a 10% (w / w) aqueous acetic acid solution was added at a rate of 0.08 parts / min; the aqueous acetic acid solution was prepared from 0.08 parts glacial acetic acid and 0.72 parts deionized water. The pH of the system was controlled at 4.5 ± 0.1, and hydrolysis was carried out for 30 min at 28°C and 380 r / min. The resulting hydrolysate was added dropwise to the fumed silica dispersion at a uniform rate over 270 min, with the system temperature controlled at 30 ± 2°C and the stirring speed at 700 r / min during the addition process. After the addition was complete, the system was heated to 53°C and the condensation reaction was continued at 700 rpm for 150 min. After the reaction, the mixture was filtered through a 200-mesh solvent-resistant filter cloth and washed twice with 51.0 parts and 51.0 parts of anhydrous ethanol, respectively, for 10 min each time. The washed product was dried at 70°C for 5 h to obtain 22.1 parts of epoxidized fumed silica. Nitrogen gas was continuously introduced into a closed reaction vessel at a flow rate of 0.50 L / min, and 22.1 parts of epoxidized fumed silica were added to 88.4 parts of anhydrous isopropanol and dispersed at 25°C and 1500 rpm for 20 min. The pH of the anhydrous isopropanol system was not used as a control index, and its water content should not exceed 0.10 wt%. The rotation speed was reduced to 420 rpm, and 0.8 parts of 4-amino-2,2,6,6-tetramethylpiperidine were added uniformly over 22 min. The system temperature was maintained at 39℃ during and after the addition process, and the reaction continued for 75 min after the addition was complete. After the reaction, the mixture was filtered through a 200-mesh solvent-resistant filter cloth and washed twice with 66.3 parts and 66.3 parts of anhydrous isopropanol, respectively, for 10 min each time. The product was dried at 60℃ and a vacuum gauge pressure of -0.090 MPa for 5 h to obtain 22.4 parts of hindered amine-grafted epoxidized silica bridged composite.

[0043] S4. Nitrogen gas at a flow rate of 0.50 L / min is continuously introduced into a closed reaction vessel. 42.7 parts of mercapto-β-silicon carbide nodes are added to 242.0 parts of anhydrous isopropanol and dispersed for 20 min at 25 °C and 700 r / min to prepare a mercapto-β-silicon carbide dispersion with a solid content of 15.0 wt%. The pH of the aqueous phase is not used as a control index in this anhydrous system, and the water content of the anhydrous isopropanol used is no higher than 0.10 wt%. 22.4 parts of hindered amine-grafted epoxidized silica bridging are added to the mercapto-β-silicon carbide dispersion at a rate of 0.75 parts / min. After the addition is complete, dispersion continues for 10 min. 0.143 parts of triethylamine are added, and the system is heated to 49 °C and reacted for 150 min under nitrogen protection and at 600 r / min. After determining the mercapto conversion rate to be no less than 85% using the 5,5′-dithiobis(2-nitrobenzoic acid) colorimetric method and the total epoxy group conversion rate to be 50-70% using the hydrochloric acid-acetone method, 126.9 parts of anhydrous isopropanol were added to adjust the solid content of the silicon carbide-fumed silica node composite dispersion to 15.0 wt%, and the system temperature was lowered to 33℃. Separately, 26.9 parts of aminated alkali-free E-glass ground fiber skeleton were added to 269.0 parts of anhydrous isopropanol and dispersed for 12 min under nitrogen protection, at 33℃ and 300 r / min. The silicon carbide-fumed silica node composite dispersion was then uniformly added to the aminated alkali-free E-glass ground fiber skeleton dispersion system over 300 min. After the addition was complete, the system temperature was raised to 68℃, and the reaction was carried out for 180 min under nitrogen protection and at 320 r / min. The temperature was then raised to 88℃ and held at 320 r / min for 75 min to obtain 92.0 parts of sulfide-hindered amine three-phase bridging composite precursor.

[0044] S5. The sulfide-hindered amine three-phase bridging composite precursor was filtered using a 200-mesh solvent-resistant filter cloth. It was first washed with 230.0 parts of anhydrous isopropanol for 15 min, followed by washing with 230.0 parts of anhydrous ethanol for 15 min. The pH of the non-aqueous solvents was not measured during the anhydrous isopropanol and anhydrous ethanol washing stages. 10 mL of the final washing solution was mixed with 10 mL of deionized water, and the pH of the aqueous phase was measured to be 7.0 ± 0.2. The washed filter cake was dried at 75℃ and a vacuum gauge pressure of -0.090 MPa for 9 h to reduce the volatile content to below 0.50 wt%. After drying, nitrogen gas was continuously introduced into the treatment container at a flow rate of 0.50 L / min, and the mixture was heat-treated at 110℃ for 2.5 h. After heat treatment, nitrogen gas continued to flow, and the mixture was cooled to below 40℃. The cooled product was then depolymerized at 700 r / min for 90 s. The deagglomerated powder was passed through a 60-mesh sieve, and the particles that passed through the 60-mesh sieve but were retained on the 180-mesh sieve were collected to obtain 90.5 parts of anti-aging enhancer.

[0045] like Figure 1 As shown in the figure, a relatively obvious short rod-shaped and fibrous structure is visible. Its surface is not smooth and bare, but rather covered with a large number of granular and flocculent substances, corresponding to the calcined fiber skeleton of alkali-free E-glass treated with aminosilane. The blocky or near-spherical micron-sized particles distributed around the fibers correspond to the morphology of mercapto-β-silicon carbide nodes. The fine, loose clusters covering the particle and fiber surfaces are consistent with the characteristics of fumed silica, which has a large specific surface area and easily forms secondary aggregates. The interfaces between the phases are relatively blurred, and no large number of clean, completely separated glass fibers or regular independent particles are observed. This indicates that silicon carbide and fumed silica have adhered, coated, and agglomerated around the glass fiber skeleton, forming a three-phase composite structure with a multi-scale rough surface. This is consistent with the design direction of the preparation process, which involves thiol-epoxy reaction, amino-epoxy reaction, and subsequent heat treatment to form a composite precursor.

[0046] Preparation Example 2: The anti-aging enhancer was prepared by referring to the preparation method in Preparation Example 1, except that the amount of β-silicon carbide micro powder was adjusted from 42.0 parts to 38.0 parts, and the rest remained the same as in Preparation Example 1.

[0047] Preparation Example 3: The anti-aging enhancer was prepared by referring to the preparation method in Preparation Example 1, except that the amount of hydrophilic fumed silica was adjusted from 17.0 parts to 20.0 parts, and the rest remained the same as in Preparation Example 1.

[0048] Comparative preparation example 1: The anti-aging enhancer was prepared by referring to the preparation method in Preparation Example 1, except that the β-silicon carbide micro powder was replaced with α-silicon carbide micro powder by mass, and everything else remained the same as in Preparation Example 1.

[0049] Comparative preparation example 2: The anti-aging enhancer was prepared by referring to the preparation method in Preparation Example 1, except that the hydrophilic fumed silica was replaced by precipitated silica, and everything else remained the same as in Preparation Example 1.

[0050] Comparative preparation example 3: The anti-aging enhancer was prepared by referring to the preparation method in Preparation Example 1, except that 3-aminopropyltriethoxysilane was replaced by 3-aminopropyltrimethoxysilane in equal mass, and the rest remained the same as in Preparation Example 1.

[0051] Comparative preparation example 4: The anti-aging enhancer was prepared by referring to the preparation method in Preparation Example 1, except that 3-mercaptopropyltrimethoxysilane was replaced by 3-mercaptopropyltriethoxysilane in equal mass, and the rest remained the same as in Preparation Example 1.

[0052] Comparative preparation example 5: The anti-aging enhancer was prepared by referring to the preparation method in Preparation Example 1, except that 4-amino-2,2,6,6-tetramethylpiperidine was replaced by 2,2,6,6-tetramethylpiperidine-4-ol, and the rest remained the same as in Preparation Example 1.

[0053] Example 1: Preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate: 1. Raw material composition: Epoxy resin matrix: 50.0 parts of bisphenol A type epoxy resin E-51; Anhydride curing agent: 50.0 parts of methylhexahydrophthalic anhydride; Epoxy reactive diluent: 6.0 parts of 1,4-butanediol diglycidyl ether; Toughening agent: 5.0 parts of carboxyl-terminated liquid nitrile rubber; Inorganic flame retardant: aluminum hydroxide, 18.0 parts; Flame retardant synergist: zinc borate, 3.5 parts; Curing accelerator: 0.4 parts of 2-ethyl-4-methylimidazole; Anti-aging enhancer: 29.0 parts of the anti-aging enhancer prepared in Example 1; Fiberglass reinforcement: multiaxial fabric stitch-woven composite felt, 42.0 parts.

[0054] The bisphenol A type epoxy resin E-51 was purchased from Guangzhou Weichuang High-Tech Materials Technology Co., Ltd., item number: YN-1828, with an epoxy equivalent of 184-194 g / eq.

[0055] The terminal carboxyl group liquid nitrile rubber was purchased from Kunshan Castel Polymer Materials Co., Ltd., item number: CTBN-3, with an acrylonitrile content of 18.0-22.0 wt% and a carboxyl value of 0.55-0.65 mmol / g.

[0056] The aluminum hydroxide was purchased from Zhejiang Xusen Flame Retardant Co., Ltd., product number: XS-ACW-2, with a purity ≥99.5% and a D50 particle size of 1-3μm.

[0057] The zinc borate was purchased from Zhejiang Xusen Flame Retardant Co., Ltd., product number: XS-ZB-2335, with a D50 particle size of 3-5μm.

[0058] The methylhexahydrophthalic anhydride was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., item number: B675752, epoxy value: 0.74-0.78 eq / 100g.

[0059] The 1,4-butanediol diglycidyl ether was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., item number: M824291, with a purity of 98%.

[0060] The multiaxial fabric stitch-woven composite felt was purchased from Changzhou Zhongjie Composite Materials Co., Ltd., model: EQX800 / 225.

[0061] 2. Preparation method: B1. The anti-aging reinforcing agent is dried at 80°C and a vacuum gauge pressure of -0.090 MPa for 3 hours. After drying, it is cooled to no higher than 35°C under nitrogen protection, and its volatile content is controlled to be no higher than 0.50 wt%. The aluminum hydroxide is dried at 105°C and in normal air atmosphere for 2 hours. After drying, it is sealed and cooled to no higher than 35°C, and its moisture content is controlled to be no higher than 0.20 wt%. The zinc borate is dried at 100°C and in normal air atmosphere for 2 hours. After drying, it is sealed and cooled to no higher than 35°C, and its moisture content is controlled to be no higher than 0.20 wt%. The multiaxial fabric stitch-woven composite felt is cut into two felt sheets, each with a size of 453 mm × 453 mm and a weight of 21.0 parts. The cut felt sheets are dried at 105°C and in normal air atmosphere for 2 hours. After drying, they are transferred to a sealed drying container and cooled to 25-30°C, and their moisture content is controlled to be no higher than 0.10 wt%. Dry nitrogen gas at a flow rate of 0.30 L / min was continuously introduced into a mixing container. The bisphenol A type epoxy resin E-51 and the carboxyl-terminated liquid nitrile rubber were added. The mixture was heated to 70°C and stirred at 600 r / min for 40 min. The system temperature was maintained at 70 ± 2°C, and the stirring speed was adjusted to 500 r / min. The 1,4-butanediol diglycidyl ether was added at a rate of 0.6 parts / min. After the addition was complete, stirring was continued for 10 min. The system temperature was lowered to 65°C, the stirring speed was adjusted to 300 r / min, and the vacuum pressure was adjusted to -0.090 MPa. Dehydration and degassing were performed for 15 min to obtain the resin premix.

[0062] B2. Maintain the temperature of the resin premix at 65±2℃ and stir at 700 r / min, adding aluminum hydroxide at a rate of 1.8 parts / min; after the aluminum hydroxide is added, add zinc borate at a rate of 0.7 parts / min. After the aluminum hydroxide and zinc borate are added, under conditions of dry nitrogen flow rate of 0.30 L / min and system temperature of 60-65℃, increase the shear speed to 2700 r / min and shear dispersion for 15 min. Reduce the shear speed to 750 r / min and add the anti-aging reinforcing agent in four batches, with 7.25 parts added in each batch, each batch added within 2 min, with a 5 min interval between adjacent batches. After the fourth batch of anti-aging reinforcing agent is added, continue dispersion for 25 min at 60±2℃ and 750 r / min to ensure that the anti-aging reinforcing agent is completely wetted and dispersed in the resin premix. Take another 5.0 parts of the methylhexahydrophthalic anhydride, heat to 50°C, add the 2-ethyl-4-methylimidazole, and stir at 400 r / min for 10 min to obtain an accelerator-anhydride premix. Cool the resin system containing the anti-aging reinforcing agent to 33±2°C, adjust the stirring speed to 400 r / min, and add the remaining 45.0 parts of methylhexahydrophthalic anhydride at a rate of 4.5 parts / min. After the addition is complete, add the accelerator-anhydride premix at a rate of 1.8 parts / min, and continue mixing at 33±2°C and 400 r / min for 12 min. Reduce the stirring speed to 300 r / min, and degas at 33±2°C and a vacuum gauge pressure of -0.090 MPa for 12 min to obtain an inorganic functional filler dispersion resin.

[0063] B3. Lay the two pre-dried multiaxial fabric stitch-woven composite felts flat on the release film. Divide the inorganic functional filler dispersion resin obtained in B2 into two equal parts, each 80.95 parts, and use each part to impregnate one multiaxial fabric stitch-woven composite felt. For each multiaxial fabric stitch-woven composite felt, distribute the corresponding 80.95 parts of inorganic functional filler dispersion resin evenly to both surfaces of the felt, applying 40.475 parts of inorganic functional filler dispersion resin to each surface. Control the impregnation environment temperature at 25-30℃. First, apply 40.475 parts of inorganic functional filler dispersion resin evenly to the first surface of the felt, using a scraper with a 1.5mm gap to scrape once in each of two mutually perpendicular directions, then roll back and forth with a pressure roller for 5 minutes. Turn the felt over and apply another 40.475 parts of inorganic functional filler dispersion resin to the second surface, and use the same scraping and rolling method. Impregnate the other multiaxial fabric stitch-woven composite felt using the same method. Two double-sided impregnated felt sheets were placed in vacuum bags. An exhaust medium was placed inside the vacuum bags, ensuring it did not directly contact the inorganic functional filler-dispersed resin, and no absorbent felt was used. Exhausting was performed for 20 minutes at 25-30℃ and a vacuum gauge pressure of -0.090 MPa. After exhausting, the two impregnated felt sheets were stacked, with the second sheet rotated 90° relative to the first sheet within the board surface, thus staggering the stitching positions of the two layers of multi-axial fabric-stitched composite felt. After stacking, compaction was continued for 10 minutes at 25-30℃ and a vacuum gauge pressure of -0.090 MPa to obtain a preformed board. The theoretical total mass of the obtained preformed board was 203.9 parts, with planar dimensions of 453 mm × 453 mm. The surface was free of visible dry spots, continuous bubbles, localized resin buildup, and exposed glass fiber areas. The inorganic functional filler disperses the resin, which accounts for 79.4 wt% of the total mass of the preform. The total mass of the bisphenol A epoxy resin E-51, methyl hexahydrophthalic anhydride, 1,4-butanediol diglycidyl ether, carboxyl-terminated liquid nitrile rubber, and 2-ethyl-4-methylimidazole constitutes the mass of the continuous resin phase, which accounts for 54.6 wt% of the total mass of the preform.

[0064] B4. Place the preformed sheet material in a hot press mold with a 5.5mm thick limiting structure inside the mold and close the mold. Increase the mold temperature to 85°C at a heating rate of 2°C / min, apply a pressure of 1.5MPa and hold for 25 minutes to allow the inorganic functional filler to disperse the resin flow and further impregnate the glass fiber reinforcement, while simultaneously expelling residual gas from the preformed sheet material. Then, increase the mold temperature to 128°C at a heating rate of 2°C / min, increase the pressure to 4.0MPa and hold for 50 minutes to pre-cur the epoxy resin system. Next, increase the mold temperature to 162°C at a heating rate of 2°C / min, increase the pressure to 6.5MPa and hold for 75 minutes to complete the high-temperature curing of the epoxy resin system. After high-temperature curing, maintain the 6.5MPa pressure and reduce the mold temperature to 55°C at a cooling rate not exceeding 3°C / min, release the pressure, and demold. The demolded board was placed in an air atmosphere at 180℃ and normal pressure for 2.5 hours for post-curing. After post-curing, the board was cooled to 25-30℃ at a cooling rate not exceeding 2℃ / min. The cooled board was cut into 450mm×450mm×(5.5±0.2)mm pieces, and the overflow and irregular edges were removed to obtain an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate.

[0065] Example 2-Example 3: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method of Example 1, except that the anti-aging reinforcing agent is replaced with the anti-aging reinforcing agents obtained in Preparation Examples 2-3, and the rest is the same as in Example 1.

[0066] Example 4: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method in Example 1, except that aluminum hydroxide, which is used as an inorganic flame retardant, is replaced by magnesium hydroxide by mass, and the rest is the same as in Example 1.

[0067] Example 5: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method in Example 1, except that zinc borate is replaced by zinc hydroxystannate, and the rest is the same as in Example 1.

[0068] Example 6: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method in Example 1, except that 2-ethyl-4-methylimidazole is replaced by 1-benzyl-2-methylimidazole by mass, and the rest is the same as in Example 1.

[0069] Comparative Examples 1-5: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method of Example 1, except that the anti-aging reinforcing agent is replaced in sequence with the anti-aging reinforcing agents obtained in Comparative Preparation Examples 1-5, and the rest is the same as in Example 1.

[0070] Comparative Example 6: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method in Example 1, except that the 1,4-butanediol diglycidyl ether is replaced by di(2-ethylhexyl) phthalate, and the rest is the same as in Example 1.

[0071] Comparative Example 7: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method in Example 1, except that zinc borate and other components are replaced with heavy calcium carbonate, and the rest is the same as in Example 1.

[0072] Comparative Example 8: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method in Example 1, except that the multiaxial fabric stitch-woven composite felt is replaced with basalt fiber multiaxial fabric, and the rest is the same as in Example 1.

[0073] Comparative Example 9: The preparation of an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate is carried out by referring to the preparation method in Example 1, except that the anti-aging reinforcing agent is replaced by needle-shaped wollastonite powder, and the rest is the same as in Example 1.

[0074] Performance testing: The test subjects were the anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplates prepared in Examples 1-6 and Comparative Examples 1-9. Samples were cut from a position at least 20 mm from the edge of the plate, and samples from the same test were taken in the same direction. Unless otherwise specified, the samples were conditioned for 48 hours at a temperature of 23±2℃ and a relative humidity of 50±5%.

[0075] 1. Initial bending strength test: conducted according to GB / T1449-2005. The sheet metal was processed into strip-shaped specimens with a length of 120 mm, a width of 15.0 ± 0.2 mm, and a thickness of 5.5 ± 0.2 mm. A three-point bending method was used, with the support span set at 16 times the measured thickness of the specimen. The loading head was located at the midpoint of the span, and the test speed was 2 mm / min. The maximum load at specimen failure was recorded, and the initial bending strength was calculated in MPa. The data are shown in Table 1.

[0076] 2. Bending strength retention rate test after thermo-oxidative aging: The thermo-aging procedure was conducted according to GB / T7141-2008. Samples of the same specifications as those used in the initial bending strength test were vertically suspended in a forced-ventilation aging chamber, with a spacing of at least 20 mm between samples, and treated at 120±2℃ for 500 hours. After treatment, the samples were removed and allowed to recover for 24 hours in an environment of 23±2℃ and 50±5% relative humidity, and then the bending strength was measured according to GB / T1449-2005. The bending strength retention rate after thermo-oxidative aging was calculated as the ratio of the aging bending strength to the initial bending strength, expressed as a percentage. The data are shown in Table 1.

[0077] 3. Damp heat aging performance test: According to GB / T2573-2008, the samples were continuously treated in a damp heat chamber at 60±2℃ and 93±3% relative humidity for 1000h. Before treatment, the sample mass m0 was weighed. After treatment, surface moisture was wiped off within 5min, and the mass m1 was weighed. The damp heat mass increase rate was calculated as (m1-m0) / m0×100%. Another sample with the same treatment was taken and, after recovering in a standard environment for 24h, its flexural strength was determined according to GB / T1449-2005, and the flexural strength retention rate after damp heat aging was calculated. The data are shown in Table 1.

[0078] 4. Oxygen Index and Oxygen Index After Damp Heat Treatment: Tested according to GB / T8924-2005. The sheet metal was processed into specimens with a length of 150 mm, a width of 6.5 ± 0.5 mm, and a thickness of 3.0 ± 0.2 mm. The oxygen index of the unaged specimens and the specimens treated with damp heat according to Test Method 3 were tested separately. During the test, the oxygen volume fraction in the oxygen-nitrogen mixture was adjusted stepwise. The lowest oxygen concentration at which the specimen maintained a specified combustion time or reached a specified combustion length was taken as the oxygen index. The results are expressed as a volume fraction in %. The data are shown in Table 1.

[0079] 5. Volume resistivity test after damp heat treatment: Performed according to GB / T31838.2-2019. The plate was processed into 100mm×100mm×5.5mm samples. After damp heat treatment according to test method 3, surface moisture was wiped off, and the samples were placed in a standard environment for 2 hours. A three-electrode device with a guard ring was used, and a 500V DC voltage was applied. After 60 seconds of energization, the stable current was recorded. The volume resistivity was calculated based on the effective electrode area and the measured thickness of the sample, in Ω·m. The data are shown in Table 1.

[0080] Table 1. Performance test results of the examples and comparative examples. The test results show that the boards obtained in the examples exhibit relatively stable performance in terms of initial bending properties, mechanical properties after thermo-oxidative and hygrothermal treatment, flame retardant retention, and insulation properties after hygrothermal treatment. The glass fiber skeleton in the anti-aging reinforcing agent forms a load transfer path, silicon carbide nodes limit crack propagation, and the fumed silica bridging phase improves particle spacing, resin wetting, and interfacial compatibility. After the hindered amine is fixed by chemical bonds, its migration and local enrichment are limited, which can delay the performance degradation of the resin matrix and fiber interface under thermo-oxidative conditions. Changing the silica morphology or silane type reduces the degree of interfacial reaction and dispersion stability; using non-reactive diluents decreases the continuity of the cured network and moisture resistance; replacing the flame retardant synergist or the overall anti-aging reinforcing agent with conventional fillers affects the surface barrier layer, insulation spacing structure, and reinforcing path, resulting in a corresponding decrease in the performance of the comparative examples.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A nanoplate for encapsulating power batteries using an anti-aging fumed silica-silicon carbide-glass fiber filament substrate, characterized in that, It is composed of the following components in parts by weight: 45-55 parts epoxy resin matrix, 43-61 parts acid anhydride curing agent, 4-8 parts epoxy reactive diluent, 3-7 parts toughening agent, 14-22 parts inorganic flame retardant, 2-5 parts flame retardant synergist, 0.2-0.6 parts curing accelerator, 22-36 parts anti-aging reinforcing agent, and 35-50 parts glass fiber reinforcement; The ratio of the equivalent number of anhydride groups in the anhydride curing agent to the total equivalent number of epoxy groups in the epoxy resin matrix and the epoxy reactive diluent is 0.90-1.00:1; The anti-aging reinforcing agent comprises a reinforcing skeleton composed of ammoniated alkali-free E glass ground fibers, spaced-apart mercapto-modified β-silicon carbide nodes, and an epoxidized fumed silica bridging phase located between the mercapto-modified β-silicon carbide nodes and the reinforcing skeleton.

2. The anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 1, characterized in that, The anti-aging enhancer is composed of the following raw materials by weight: 38-46 parts of β-silicon carbide micro powder, 22-30 parts of alkali-free E glass ground fiber, 14-20 parts of hydrophilic fumed silica, 1.8-3.0 parts of 3-aminopropyltriethoxysilane, 1.5-2.5 parts of 3-mercaptopropyltrimethoxysilane, 5.0-7.0 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and 0.6-1.1 parts of 4-amino-2,2,6,6-tetramethylpiperidine.

3. The anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 2, characterized in that, The preparation method of the anti-aging enhancer includes the following steps: S1. The alkali-free E-glass ground fibers are added to a sodium hydroxide aqueous solution with a mass concentration of 2.0-3.0% (10-12 times their weight) and treated at 45-50℃ for 20-30 min, then washed and dried. The 3-aminopropyltriethoxysilane is added to a mixture of anhydrous ethanol and deionized water, wherein the mass of anhydrous ethanol and deionized water is 3.5-4.5 times and 0.35-0.50 times the mass of the alkali-free E-glass ground fibers, respectively. The pH is adjusted to 4.5-5.0 using a 10% acetic acid aqueous solution, and hydrolyzed at 25-30℃ for 25-35 min. The alkali-treated alkali-free E-glass ground fibers are then added, and the reaction is carried out at 55-60℃ for 120-150 min. The mixture is filtered, washed, and vacuum dried to obtain an amino-modified glass fiber skeleton. S2. Add the β-silicon carbide micro powder to a 6-8% hydrogen peroxide aqueous solution at 3-4 times its mass. Add 2-4 parts of anhydrous sodium carbonate per 100 parts of β-silicon carbide micro powder, adjust the pH to 9.5-10.5, and treat at 65-72℃ for 75-105 minutes. Wash and dry. Under nitrogen protection, add the 3-mercaptopropyltrimethoxysilane to a mixture of anhydrous ethanol and deionized water. Anhydrous ethanol and deionized water were added at 3.0-3.8 times and 0.30-0.45 times the mass of β-silicon carbide micropowder, respectively. The pH was adjusted to 4.2-4.8 using a 10% acetic acid aqueous solution. The mixture was hydrolyzed at 25-30℃ for 25-35 min. The oxidized and activated β-silicon carbide micropowder was then added, and the mixture was reacted at 50-56℃ for 120-150 min. The mixture was then filtered, washed, and vacuum dried to obtain mercapto-modified silicon carbide nodes. S3. Disperse the hydrophilic fumed silica in anhydrous ethanol and deionized water, wherein the mass of anhydrous ethanol and deionized water is 3.5-4.5 times and 0.35-0.50 times the mass of the hydrophilic fumed silica, respectively; add the γ-glycidoxypropyltrimethoxysilane to the mixture of anhydrous ethanol and deionized water, wherein the mass of anhydrous ethanol and deionized water is 1.8-2.4 times and 0.18-0.30 times the mass of the hydrophilic fumed silica, respectively; adjust the pH to 4.3-4.8 using a 10% aqueous acetic acid solution; and hydrolyze at 25-30°C for 25-35 minutes. The obtained hydrolysate was added to a hydrophilic fumed silica dispersion and reacted at 50-56℃ for 120-180 min. After filtration, washing, and drying, epoxidized fumed silica was obtained. Under nitrogen protection, the epoxidized fumed silica was dispersed in anhydrous isopropanol at 3.5-4.5 times its mass. The 2,2,6,6-tetramethylpiperidineamine was added at a rate of 0.10-0.25 mL / min per 100 g of epoxidized fumed silica. After reacting at 35-42℃ for 60-90 min, the mixture was filtered, washed, and vacuum dried to obtain a hindered amine-grafted epoxidized fumed silica bridge. S4. Under nitrogen protection, the mercaptolated silicon carbide nodes are dispersed in anhydrous isopropanol to prepare a dispersion with a solid content of 12-18 wt%. The hindered amine-grafted epoxidized fumed silica bridge is added, and 0.15-0.30 parts of triethylamine are added based on 100 parts of the total mass of the two. The reaction is carried out at 45-52℃ for 120-180 min to obtain a silicon carbide-fumed silica node composite. The aminated glass fiber skeleton is dispersed in anhydrous isopropanol at 8-12 times its mass. The silicon carbide-fumed silica node composite is added at a dry basis rate of 0.5-1.0 g / min per 100 g of aminated glass fiber skeleton. The reaction is carried out at 65-72℃ for 150-210 min, and then kept at 85-90℃ for 60-90 min to obtain a sulfide-hindered amine three-phase bridged composite precursor. S5. Filter the sulfide-hindered amine three-phase bridging composite precursor, wash it sequentially with 2-3 times its mass of anhydrous isopropanol and 2-3 times its mass of anhydrous ethanol based on the dry weight of the precursor, dry it for 8-10 hours at 70-80℃ and vacuum gauge pressure of -0.095 to -0.080 MPa, then heat it at 105-115℃ for 2-3 hours under nitrogen protection, depolymerize it at a speed not exceeding 800 r / min for 1-2 minutes, pass it through a 60-mesh sieve and collect the particles trapped on the 180-mesh sieve to obtain the anti-aging enhancer.

4. The anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 1, characterized in that, The epoxy resin matrix is ​​bisphenol A type epoxy resin E-51.

5. The anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 1, characterized in that, The anhydride curing agent is methyl hexahydrophthalic anhydride; The epoxy-based reactive diluent is 1,4-butanediol diglycidyl ether.

6. The anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 1, characterized in that, The toughening agent is a carboxyl-terminated liquid nitrile rubber; The inorganic flame retardant is selected from aluminum hydroxide and magnesium hydroxide; The flame retardant synergist is one of zinc borate or zinc hydroxystannate.

7. The anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 1, characterized in that, The curing accelerator is selected from one of 2-ethyl-4-methylimidazol and 1-benzyl-2-methylimidazol; The fiberglass reinforcement is a multiaxial stitch-woven composite felt.

8. A method for preparing an anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to any one of claims 1-7, characterized in that, Includes the following steps: B1 pre-dries the anti-aging reinforcing agent, inorganic flame retardant, flame retardant synergist and glass fiber reinforcement; mix the epoxy resin matrix and toughening agent and heat and stir; after the toughening agent is evenly dispersed, add the epoxy reactive diluent; dehydrate and degas under vacuum conditions to obtain resin premix. B2. Under stirring conditions, the dried inorganic flame retardant and flame retardant synergist are sequentially added to the resin premix and dispersed by high-speed shearing; after reducing the stirring speed, the anti-aging reinforcing agent is added in batches to ensure that the anti-aging reinforcing agent is uniformly wetted and dispersed in the resin premix; the system temperature is reduced, the acid anhydride curing agent and curing accelerator are added, and after mixing evenly, vacuum degassing is performed to obtain the inorganic functional filler dispersion resin. B3. The inorganic functional filler dispersion resin is applied to the surface of the pre-dried glass fiber reinforcement, so that the inorganic functional filler dispersion resin is impregnated into the fiber gaps of the glass fiber reinforcement; The impregnated glass fiber reinforcement is scraped with adhesive, vacuum degassing, and laminated to obtain a preformed board. B4. The preformed plate is placed in a hot press mold and subjected to low-temperature flow venting, medium-temperature pre-curing and high-temperature curing in sequence; after curing, pressure is maintained and the plate is cooled, and after demolding, post-curing and cutting are performed to obtain the anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate.

9. The method for preparing the anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 8, characterized in that, In B1, the epoxy resin matrix and toughening agent are mixed at 65-75°C and 500-700 r / min for 30-45 min, and after adding the epoxy reactive diluent, the mixture is dehydrated and degassed for 10-20 min under a vacuum gauge pressure of -0.095 to -0.085 MPa. In step B2, after adding the inorganic flame retardant and flame retardant synergist to the resin premix, it is sheared and dispersed at 2200-3200 r / min for 10-20 min. After reducing the rotation speed to 600-900 r / min, the anti-aging reinforcing agent is added in 3-5 batches and the dispersion continues for 20-30 min. The system temperature is then reduced to 30-35℃, and the acid anhydride curing agent and curing accelerator are added. The mixture is then mixed at 300-500 r / min for 10-15 min, and then degassed at a vacuum gauge pressure of -0.095-0.085 MPa for 8-15 min.

10. The method for preparing the anti-aging fumed silica-silicon carbide-glass fiber power battery encapsulation nanoplate according to claim 8, characterized in that, In step B3, the impregnated glass fiber reinforcement is placed under a vacuum gauge pressure of -0.095 to -0.085 MPa for 15-30 minutes to remove air. In B4, the segmented hot-press curing process includes: holding pressure at 80-90℃ and 1-2MPa for 20-30 minutes, holding pressure at 120-135℃ and 3-5MPa for 40-60 minutes, and holding pressure at 155-170℃ and 5-8MPa for 60-90 minutes; after curing, cooling to no higher than 60℃ while maintaining a pressure of 5-8MPa, and then post-curing at 175-185℃ for 2-3 hours after demolding.

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