An insulating adhesive tape for new energy batteries and a preparation method thereof

Abstract

The application discloses a new energy battery insulating adhesive tape and a preparation method thereof, and relates to the technical field of new energy battery components. The new energy battery insulating adhesive tape is prepared by coating a pretreated glass fiber cloth with a coating material. The coating material comprises the following raw materials in parts by weight: 15-20 parts of modified polyimide resin, 2-4 parts of epoxy resin E-51, 71-77 parts of ethanol / butanone mixed solvent, 3-5 parts of modified nanometer silicon dioxide, 0.2-0.4 parts of silane coupling agent KH-550, 0.1-0.3 parts of polydimethylsiloxane, 0.1-0.2 parts of paraffin-based mineral oil and 0.3-0.5 parts of triethylene tetramine. The pretreatment material of the glass fiber cloth comprises deionized water and a 5%-8% sodium hydroxide solution. The new energy battery insulating adhesive tape contains modified polyimide resin, which can enhance the high-temperature resistance and electrolyte resistance of the adhesive tape, improve the insulation property and improve the dispersibility of the modified nanometer silicon dioxide. The preparation process is fine, the pretreatment of the glass fiber cloth is sufficient, the preparation process is standard, and the new energy battery insulating adhesive tape can meet the use requirements of new energy batteries.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy battery components, in particular to an insulating tape for new energy batteries and a preparation method thereof. BACKGROUND

[0002] Under the background of rapid development of the new energy industry, the safety, stability and service life of the power battery as the core energy supply component are crucial to the vehicle performance, and the insulating tape as the key insulating protective material inside the battery directly affects the reliability of the battery operation.

[0003] The traditional insulating tape on the current market is mostly made of ordinary resin as the base material and single filler, which has obvious performance short board. On the one hand, the traditional resin has insufficient high temperature resistance, and in the process of charging and discharging of the power battery, heat of 40-80℃ is easily generated inside the battery due to chemical reaction, and the temperature even breaks through 100℃ under some extreme conditions, at which time the ordinary insulating tape is prone to softening and deformation, resulting in failure of the insulating layer and causing the risk of internal short circuit of the battery; on the other hand, the electrolyte inside the battery has strong corrosiveness, and after the resin matrix of the traditional tape contacts with the electrolyte, swelling and degradation are easily caused, resulting in decrease of the adhesive force of the tape, delamination and further damage to the insulating structure.

[0004] At the same time, the filler of the traditional insulating tape, such as silica and calcium carbonate, has poor dispersibility and is prone to agglomeration in the base material, which not only cannot improve the mechanical properties and insulating properties of the tape, but also produces local weak points, reducing the overall protection effect of the tape. In addition, the base material of some insulating tapes, such as ordinary cotton cloth and polyester film, has low mechanical strength, and is prone to damage due to external pressure and vibration during battery assembly and long-term use, which cannot maintain a stable insulating protection state for a long time.

[0005] These problems seriously restrict the safety and service life of the power battery, and cannot meet the use requirements of new energy vehicles for power batteries in terms of high safety, long service life and resistance to harsh working conditions, therefore, it is a key problem to be solved in the industry to develop an insulating tape for new energy batteries with high temperature resistance, electrolyte corrosion resistance, stable insulating properties and excellent mechanical properties. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides an insulating tape for new energy batteries and a preparation method thereof, which solves the problems of insufficient insulating properties, poor high temperature resistance and weak electrolyte resistance of traditional new energy tapes.

[0007] To achieve the above purpose, the present application is realized by the following technical scheme:

[0008] The application discloses a new energy battery insulating adhesive tape which is prepared from a pretreated glass fiber cloth coated with a coating, wherein the coating comprises the following raw materials in parts by weight: 15-20 parts of modified polyimide resin, 2-4 parts of epoxy resin E-51, 71-77 parts of ethanol / butanone mixed solvent, 3-5 parts of modified nano silicon dioxide, 0.2-0.4 parts of silane coupling agent KH-550, 0.1-0.3 parts of polydimethylsiloxane, 0.1-0.2 parts of paraffin-based mineral oil and 0.3-0.5 parts of triethylene tetramine; and the pretreated material of the glass fiber cloth comprises deionized water and a 5%-8% sodium hydroxide solution.

[0009] Further, the volume ratio of ethanol to butanone in the ethanol / butanone mixed solvent is 3:1.

[0010] Further, the modified nano silicon dioxide is prepared according to the following steps:

[0011] A1, take nano silicon dioxide, add deionized water to stir at 300 r / min and ultrasonic dispersion for 30-40 min, promote the dispersion of nano silicon dioxide, drop 0.1 mol / L hydrochloric acid to adjust pH to 4.0-4.5, then add polyvinyl alcohol-1788 to stir to dissolve at 500 r / min, heat to 55-65 DEG C and stir for 1 h, then slowly drop silane coupling agent KH-570, and heat and stir for 5-6 h to introduce organic functional groups, preliminarily improve the compatibility with the resin; after the reaction, stand for 2 h, the hydroxyl groups of the hydrolyzed silicon and the hydroxyl groups on the surface of the nano silicon dioxide are adsorbed through hydrogen bonds, and the adsorbed intermediates further undergo dehydration condensation to form stable covalent bonds, providing sufficient time for the grafting of the organic groups on the surface of the nano silicon dioxide, ensuring that the silane coupling agent is combined with the surface of the nano silicon dioxide to the maximum extent, avoiding the defect of incomplete modification, and then centrifugal separation, the precipitate is washed to neutral with deionized water, then washed with ethanol for 2 times, and vacuum dried at 85-95 DEG C for 7-9 h to obtain the first modified nano silicon dioxide;

[0012] A2, take the first modified nano silicon dioxide, add anhydrous ethanol to stir at 300 r / min and ultrasonic dispersion for 25-35 min, then add azobisisobutyronitrile to continue stirring and ultrasonic dispersion for 5-10 min, heat to 75-85 DEG C under nitrogen protection, slowly drop acrylic acid, after the dropping is completed, heat and react at 500 r / min for 7-8 h to realize the grafting of the acrylic acid, further enhance the organic phase affinity and reduce the agglomeration; after the reaction is completed, naturally cool to room temperature, filter, wash with anhydrous ethanol for 5 times, and then vacuum dry at 100-110 DEG C for 5-7 h to obtain the second modified nano silicon dioxide;

[0013] A3, taking the second modified nano-silicon dioxide, adding deionized water to stir at 300 r / min and ultrasonic dispersion for 20-30 min, then adding aluminum chloride and stirring until dissolved, then slowly adding 25% ammonia water to adjust the pH to 7.5-8.0, stirring at room temperature at 500 r / min for 3-4 h, forming an aluminum chloride coating layer, building a physical barrier layer, and improving electrolyte resistance; after the reaction, centrifugal separation is performed, the precipitate is washed with deionized water until the washing liquid does not produce white precipitate after adding silver nitrate solution, and then vacuum drying at 90-100℃ for 6-8h to obtain modified nano-silicon dioxide.

[0014] Further, the amount ratio of nano-silicon dioxide, deionized water, polyvinyl alcohol-1788 and silane coupling agent KH-570 in A1 is 400-500g:800-1000ml:20-30g:25-35ml.

[0015] Further, the amount ratio of the first modified nano-silicon dioxide, anhydrous ethanol, azobisisobutyronitrile and acrylic acid in A2 is 300-350g:700-800ml:0.8-1.5g:25-35g.

[0016] Further, the amount ratio of the second modified nano-silicon dioxide, deionized water and aluminum chloride in A3 is 250-300g:600-700ml:12-18g.

[0017] Further, the modified polyimide resin is prepared according to the following specific steps:

[0018] B1, adding N,N-dimethylformamide into a four-necked flask, adding m-phenylenediamine and 4,4'-diamino diphenyl ether under nitrogen protection, stirring at 400 r / min until dissolved, controlling the temperature at 0-5℃; adding pyromellitic dianhydride in 3-4 times, stirring for 30-40 min after each addition to avoid local reaction too fiercely, continuing to stir for 2-3h after the viscosity of the system reaches 5000-8000 mPa・s, to obtain a copolymerized polyamide acid solution;

[0019] B2, adding dimethylbenzene into the copolymerized polyamide acid solution to stir uniformly at 500 r / min to form a mixed system; adding maleic anhydride and dicumyl peroxide, heating to 85-95℃ under nitrogen protection, stirring to reflux for 4-5h; after the reaction, heating to 120-130℃, imidizing at 300 r / min for 2-3h to complete the imidization process, build a graft structure, and improve the thermal stability; after cooling to room temperature, filtering, washing with dimethylbenzene for 3 times, and then vacuum drying at 120-130℃ for 6-8h to obtain a graft modified polyimide resin;

[0020] B3, grafting modified polyimide resin, adding volume ratio 3:1 ethanol / butyron mixed solvent, stirring to dissolve at 400 r / min; adding epoxy resin E-51 and triethylene tetramine, stirring uniformly at 500 r / min, then heating to 60-70 DEG C and stirring for 3-4 h, during which gel time is measured every 1 h, and when the gel time is stable at 30-40 min, the reaction is stopped to ensure appropriate crosslinking degree; pouring the solution into water to precipitate, filtering and washing with ethanol for 3 times, and precipitating in a vacuum dryer at 130-140 DEG C for 7-9 h to obtain modified polyimide resin.

[0021] Further, the use amount ratio of N,N-dimethylformamide, m-phenylenediamine, 4,4'-diamino diphenyl ether and pyromellitic dianhydride in B1 is 200-250 ml:30-40 g:15-20 g:40-50 g.

[0022] Further, the use amount ratio of copolymer polyamic acid solution, dimethylbenzene, maleic anhydride and dicumyl peroxide in B2 is 300-350 ml:500-600 ml:8-12 g:0.5-1 g.

[0023] Further, the use amount ratio of grafting modified polyimide resin, ethanol / butyron mixed solvent, epoxy resin E-51 and triethylene tetramine in B3 is 120-150 g:400-500 ml:15-20 g:2-3 g.

[0024] A preparation method of an insulating adhesive tape for new energy batteries, specifically comprising the following steps:

[0025] S1, the glass fiber cloth is put into deionized water, stirred at 300 r / min for 15 min, the surface dust and loose fibers are removed, and then the glass fiber cloth is taken out and drained; it is transferred into 5%-8% sodium hydroxide solution, stirred at 200 r / min for 20 min at 60-70 DEG C, the cloth surface is activated, and hydroxyl active sites are generated; deionized water is used for stirring and washing until the pH is neutral, and then it is dried in an oven at 120-130 DEG C for 2-3 h, and cooled for standby, which creates conditions for subsequent combination with paint and avoids impurities or moisture affecting the adhesive force and insulation of the adhesive tape;

[0026] S2, the modified polyimide resin and epoxy resin E-51 are added to the ethanol / butyron mixed solvent, and stirred at 400-600 r / min at 50-60 DEG C to promote the complete dissolution of the modified polyimide resin and the epoxy resin E-51, forming a clear resin solution to avoid uneven coating caused by undissolved raw materials;

[0027] S3, taking modified nano-silica, adding ethanol / butyron mixed solvent and silane coupling agent KH-550, first stirring at 800 r / min for 15 min, then ultrasonic dispersion for 10-15 min for pretreatment; then slowly adding the pretreated modified nano-silica into the resin liquid of S2, stirring at 1000-1200 r / min while adding, continuing to stir at high speed for 25-35 min after adding, then transferring into ice water bath environment for ultrasonic dispersion for 20-30 min, ensuring that the nano-silica does not agglomerate; pretreating and dispersing the modified nano-silica, high-speed stirring and low-temperature ultrasonic are used to break the agglomeration and ensure uniform dispersion in the resin liquid, stirring for 30 s every 5 min to further strengthen the dispersion effect;

[0028] S4, adding polydimethylsiloxane and paraffin-based mineral oil to the dispersion system of S3, adjusting the stirring speed to 300-400 r / min to avoid introducing air bubbles at high speed, stirring at room temperature for 15-25 min to make the additives uniformly dispersed; introducing nitrogen, slowly adding triethylenetetramine into the system, stirring at 300-400 r / min for 15-20 min to ensure that the curing agent is completely integrated without obvious particles or stratification;

[0029] S5, filtering the prepared coating with a 800-1000 mesh nylon filter screen, and naturally removing the residual small air bubbles in the system by placing the filtered coating at room temperature for 30-60 min, to obtain an insulating tape coating that can be used for coating;

[0030] S6, laying the pretreated glass fiber cloth on the conveying belt of the coating machine, and uniformly coating the above-mentioned coating on both sides of the cloth with a coating thickness of 0.05-0.1 mm; after coating, the substrate is sent into a drying oven for processing according to a ladder curing program: drying at 90-95℃ for 25-35 min, then increasing the temperature to 125-135℃ for drying for 55-65 min, and finally increasing the temperature to 175-185℃ for drying for 110-130 min, to fully complete the curing reaction and ensure the high temperature resistance and electrolyte resistance of the adhesive tape, obtaining an insulating tape for new energy batteries.

[0031] Further, the temperature of the ice water bath environment in S3 is controlled at 0-5℃, the ultrasonic dispersion power is 300-500 W, and the stirring is performed every 5 min during the ultrasonic process, with a stirring time of 30 s each time, to further avoid agglomeration of the modified nano-silica.

[0032] Further, the coating speed of the coating machine in S6 is 1-2 m / min, and hot air assisted drying is used during the coating process, with a hot air temperature of 40-50℃ and a hot air speed of 1-1.5 m / s, to prevent the coating from causing uneven thickness due to sagging during the coating process, and to preliminarily remove part of the solvent.

[0033] The application provides an insulating adhesive tape for new energy batteries and a preparation method thereof, and has the following beneficial effects:

[0034] 1、The application builds a high-density three-dimensional network molecular structure through the synergistic crosslinking of modified polyimide resin and epoxy resin E-51, that is, after the modified polyimide resin is grafted with maleic anhydride and copolymerized with the epoxy resin, a large number of heat-resistant aromatic rings and crosslinking sites are introduced into the molecular chain, and triethylenetetramine is used as a curing agent to further strengthen the intermolecular bonding force; at the same time, after the pretreated glass fiber cloth is activated by sodium hydroxide, hydroxyl active sites are formed on the surface, which can be chemically bonded with silane coupling agent KH-550 in the paint, so that the fiber cloth is tightly combined with the resin matrix. The double structure design of “resin crosslinking + substrate bonding” enables the insulating adhesive tape to maintain a stable form after curing at 175-185 DEG C, and even under the extreme conditions of battery charging and discharging, it will not soften, deform or delaminate, and can maintain the integrity of the insulating structure for a long time, effectively avoiding the risk of short circuit caused by high temperature.

[0035] 2、On the one hand, after the modified nanometer silicon dioxide is coupled with KH-570, grafted with acrylic acid and coated with aluminum chloride, functional groups with organic affinity are formed on the surface, which can be uniformly dispersed in the resin matrix, filling the small gaps between the resin molecules and forming a dense physical barrier layer to prevent the penetration of corrosive ions in the electrolyte; on the other hand, after the chemical corrosion-resistant imide ring in the molecular chain structure of the modified polyimide resin is crosslinked with the epoxy group of the epoxy resin, the hydrophilicity and electrolyte swelling of the resin matrix are further reduced, avoiding swelling and degradation of the adhesive tape after contact with the electrolyte. Under the dual protection, the insulating adhesive tape can maintain stable insulation performance and mechanical strength even after long-term immersion in the battery electrolyte, greatly reducing the failure of the adhesive tape caused by electrolyte corrosion, and indirectly prolonging the overall service life of the power battery.

[0036] 3、In terms of insulation performance, the uniform dispersion of modified nanometer silicon dioxide not only fills the micro gaps of the resin matrix, but also reduces the local conductive path inside the adhesive tape, and the excellent insulation properties of the modified polyimide resin itself make the overall volume resistivity of the adhesive tape greatly improved, effectively blocking the risk of leakage between different electrodes in the battery; in terms of mechanical properties, the pretreated glass fiber cloth retains its mechanical strength and has significantly enhanced bonding force with the resin matrix, forming a composite structure of “fiber reinforcement-resin bonding”, which enables the adhesive tape to have excellent tensile and tear resistance - even under external pressure, winding or vibration during battery assembly, it is not easy to break or crack; in long-term use, it can also resist the stress impact caused by the deformation of the internal structure of the battery, continuously maintaining stable insulation protection effect, providing double safety protection for battery assembly and long-term operation.

[0037] 4、In the preparation process, the modified nano-silica is first pretreated with silane coupling agent KH-550 in an ethanol / butyron mixed solvent, and then dispersed by high-speed stirring and ice water bath ultrasonic dispersion, effectively avoiding nanoparticle agglomeration and ensuring uniform distribution in the resin liquid; at the same time, during the preparation of the coating, the stirring speed is adjusted in a stepwise manner, and the coating is filtered through an 800-1000 mesh nylon filter screen and left to stand at room temperature to remove bubbles, so that the coating has uniform texture, no impurities and no bubbles. This uniform coating system, combined with a stable coating speed of 1-2 m / min of the coating machine and hot air assisted drying, can ensure that the coating forms a uniform coating on both sides of the glass fiber cloth, avoiding the problem of local performance weakness caused by uneven coating thickness, and ultimately achieving high consistency of product performance in batch production, reducing the rate of defective products in the production process, and improving the industrial application value. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0039] Example 1, preparation of an insulating tape for new energy batteries, the specific preparation steps are as follows:

[0040] S1, put the glass fiber cloth into deionized water, stir at 300 r / min for 15 min to remove surface dust and loose fibers, then drain; transfer to 5% sodium hydroxide solution, stir at 200 r / min for 20 min at 60°C to activate the cloth surface; wash with deionized water until the pH is neutral, then dry in a 120°C oven for 2 h, and cool for standby;

[0041] S2, take 15 parts of polyimide resin, 2 parts of epoxy resin E-51, add to 70 parts of ethanol / butyron mixed solvent, stir at 400 r / min until the resin is completely dissolved at 50°C, forming a clear and transparent resin liquid;

[0042] S3, take 3 parts of nano-silica, add 1 part of ethanol / butyron mixed solvent and 0.2 parts of silane coupling agent KH-550, first stir at 800 r / min for 15 min, then ultrasonic dispersion for 10 min for pretreatment; then slowly add the pretreated nano-silica to the resin liquid of S2, stir at 1000 r / min while adding, continue to stir at high speed for 25 min after adding, then transfer to an ice water bath environment for ultrasonic dispersion for 20 min, the temperature is controlled at 0°C, the ultrasonic dispersion power is 300W, and the stirring is carried out every 5 min during the ultrasonic process, each time for 30s, to ensure that the nano-silica does not agglomerate;

[0043] S4, 0.1 parts of polydimethylsiloxane and 0.1 parts of paraffin-based mineral oil are added to the S3 dispersion system, the stirring speed is adjusted to 300 r / min, and stirring is carried out at room temperature for 15 min to uniformly disperse the additives; nitrogen is introduced, and 0.3 parts of triethylene tetramine is slowly added to the system, stirred at 300 r / min for 15 min, and the curing agent is completely dissolved without obvious particles or stratification;

[0044] S5, the prepared paint is filtered with an 800 mesh nylon filter screen, and the filtered paint is left to stand at room temperature for 30 min to naturally remove the residual microbubbles in the system, obtaining an insulating tape coating that can be used for coating;

[0045] S6, the pretreated glass fiber cloth is laid on the conveying belt of the coating machine, and the above-mentioned coating is uniformly coated on both sides of the cloth, the coating speed is 1 m / min, hot air is used to assist drying during the coating process, the hot air temperature is 40℃, the hot air speed is 1 m / s, and the coating thickness is 0.05 mm; after coating, the substrate is sent into a drying oven and processed according to a ladder curing program: first dried at 90℃ for 25 min, then heated to 125℃ for 55 min, and finally heated to 175℃ for 110 min to fully complete the curing reaction and ensure the performance of the tape in resisting high temperature and electrolyte, obtaining an insulating tape for new energy batteries.

[0046] Example 2, an insulating tape for new energy batteries is prepared, and the specific preparation steps are as follows:

[0047] S1, the glass fiber cloth is placed in deionized water and stirred at 300 r / min for 15 min to remove surface dust and loose fibers, then taken out and drained; then transferred into 8% sodium hydroxide solution, stirred at 200 r / min for 20 min at 70℃ to activate the cloth surface; washed with deionized water until the pH is neutral, and then dried in an oven at 130℃ for 3 h and cooled for standby;

[0048] S2, 20 parts of polyimide resin and 4 parts of epoxy resin E-51 are added to 75 parts of ethanol / butyron mixed solvent, stirred at 600 r / min at 60℃ until the resin is completely dissolved, forming a clear and transparent resin solution;

[0049] S3, take 5 parts of nano-silicon dioxide, add 2 parts of ethanol / butyron mixed solvent and 0.4 parts of silane coupling agent KH-550, first stir at 800 r / min for 15 min, then ultrasonic dispersion for 15 min for pretreatment; then slowly add the pretreated nano-silicon dioxide into the resin liquid of S2, stirring at 1200 r / min while adding, continue to stir at high speed for 35 min after adding, then transfer into ice water bath environment for ultrasonic dispersion for 30 min, temperature control at 5℃, ultrasonic dispersion power is 500W, and stirring once every 5 min during ultrasonic process, each stirring time is 30s, to ensure that the nano-silicon dioxide does not agglomerate;

[0050] S4, add 0.3 parts of polydimethylsiloxane and 0.2 parts of paraffin-based mineral oil to the dispersion system of S3, adjust the stirring rate to 400 r / min, and stir at room temperature for 25 min to make the additives uniformly dispersed; introduce nitrogen, slowly add 0.5 parts of triethylene tetramine to the system, stir at 400 r / min for 20 min to ensure that the curing agent is fully integrated without obvious particles or stratification;

[0051] S5, filter the prepared coating with a 1000 mesh nylon filter screen, and let the filtered coating stand at room temperature for 60 min to naturally remove the remaining small bubbles in the system, obtaining an insulation tape coating that can be used for coating;

[0052] S6, lay the pretreated glass fiber cloth on the conveying belt of the coating machine, and evenly coat the above-mentioned coating on both sides of the cloth, the coating speed is 2 m / min, hot air assisted drying is used during the coating process, the hot air temperature is 50℃, the hot air speed is 1.5 m / s, the coating thickness is 0.1 mm; after coating, the substrate is sent into the drying oven and processed according to the ladder curing program: first dry at 95℃ for 35 min, then heat to 135℃ for 65 min, and finally heat to 185℃ for 130 min to fully complete the curing reaction, ensuring the performance of the tape in resisting high temperature and electrolyte, obtaining an insulation tape for new energy batteries.

[0053] Example 3, preparation of insulation tape for new energy batteries, the specific preparation steps are as follows:

[0054] S1, put the glass fiber cloth into deionized water, stir at 300 r / min for 15 min to remove surface dust and loose fibers, then take out and drain; transfer into 6% sodium hydroxide solution, stir at 200 r / min for 20 min at 65℃ to activate the cloth surface; wash with deionized water until the pH is neutral, then dry in a 125℃ oven for 2.5h, and cool for standby;

[0055] S2, take 17 parts of polyimide resin, 3 parts of epoxy resin E-51, add to 72 parts of ethanol / butanone mixed solvent, stir at 55°C at 500 r / min until the resin is completely dissolved, form a clear transparent resin liquid;

[0056] S3, take 4 parts of nano-silicon dioxide, add 1 part of ethanol / butanone mixed solvent and 0.3 parts of silane coupling agent KH-550, first stir at 800 r / min for 15 min, then ultrasonic dispersion for 13 min for pretreatment; then slowly add the pretreated nano-silicon dioxide into the resin liquid of S2, stir at 1100 r / min while adding, continue to stir at high speed for 30 min after adding, then transfer into ice water bath environment for ultrasonic dispersion for 25 min, control the temperature at 2°C, the ultrasonic dispersion power is 400W, and stir every 5 min during the ultrasonic process, each stirring time is 30s, to ensure that the nano-silicon dioxide does not agglomerate;

[0057] S4, add 0.2 parts of polydimethylsiloxane and 0.15 parts of paraffin-based mineral oil to the dispersion system of S3, adjust the stirring rate to 350 r / min, stir at room temperature for 20 min, make the additives uniformly dispersed; introduce nitrogen, slowly add 0.4 parts of triethylene tetramine to the system, stir at 350 r / min for 17 min, ensure that the curing agent is completely integrated, without obvious particles or stratification;

[0058] S5, filter the prepared coating with a 900 mesh nylon filter screen, the filtered coating is placed at room temperature for 45 min, naturally remove the residual small bubbles in the system, to obtain an insulation tape coating that can be used for coating;

[0059] S6, lay the pretreated glass fiber cloth on the conveying belt of the coating machine, evenly coat the above-mentioned coating on both sides of the cloth, the coating speed is 1.5 m / min, hot air assisted drying is used during the coating process, the hot air temperature is 45°C, the hot air speed is 1.2 m / s, the coating thickness is 0.08 mm; after coating, the substrate is sent into the drying oven, and the curing program is processed according to the ladder: first dry at 92°C for 30 min, then heat to 130°C for 60 min, finally heat to 180°C for 120 min, fully complete the curing reaction, guarantee the performance of the tape resistant to high temperature and electrolyte, to obtain an insulation tape for new energy battery.

[0060] Example 4, preparation of modified nano-silicon dioxide, the specific preparation steps are as follows:

[0061] A1, take 400 g of nano-silicon dioxide, add 800 ml of deionized water to stir at 300 r / min and ultrasonic dispersion for 30 min, drop 0.1 mol / L hydrochloric acid with concentration to adjust pH to 4.0, then add 20 g of polyvinyl alcohol-1788, stir to dissolve at 500 r / min, heat to 55℃ and stir for 1 h, then slowly drop 25 ml of silane coupling agent KH-570, and keep stirring for 5 h; after the reaction, stand for 2 h and then centrifugal separation, the precipitate is washed with deionized water to neutral, then washed with ethanol for 2 times, and vacuum dried at 85℃ for 7 h to obtain the first modified nano-silicon dioxide;

[0062] A2, take 300 g of the first modified nano-silicon dioxide, add 700 ml of anhydrous ethanol to stir at 300 r / min and ultrasonic dispersion for 25 min, then add 0.8 g of azobisisobutyronitrile to continue stirring and ultrasonic dispersion for 5 min, heat to 75℃ under nitrogen protection, slowly drop 25 g of acrylic acid, after dropping, keep stirring at 500 r / min for 7 h, after the reaction, naturally cool to room temperature, filter, wash with anhydrous ethanol for 5 times, and then vacuum dried at 100℃ for 5 h to obtain the second modified nano-silicon dioxide;

[0063] A3, take 250 g of the second modified nano-silicon dioxide, add 600 ml of deionized water to stir at 300 r / min and ultrasonic dispersion for 20 min, add 12 g of aluminum chloride to stir to dissolve, then slowly drop 25% ammonia water with mass fraction to adjust pH to 7.5, keep stirring at 500 r / min for 3 h at room temperature; after the reaction, centrifugal separation, the precipitate is washed with deionized water until the washing liquid has no white precipitate after adding silver nitrate solution, then vacuum dried at 90℃ for 6 h to obtain the modified nano-silicon dioxide.

[0064] Example 5, preparation of modified nano-silicon dioxide, the specific preparation steps are as follows:

[0065] A1, take 500 g of nano-silicon dioxide, add 1000 ml of deionized water to stir at 300 r / min and ultrasonic dispersion for 40 min, drop 0.1 mol / L hydrochloric acid with concentration to adjust pH to 4.5, then add 30 g of polyvinyl alcohol-1788, stir to dissolve at 500 r / min, heat to 65℃ and stir for 1 h, then slowly drop 35 ml of silane coupling agent KH-570, keep stirring for 6 h; after the reaction, stand for 2 h and then centrifugal separation, the precipitate is washed with deionized water to neutral, then washed with ethanol for 2 times, and vacuum dried at 95℃ for 9 h to obtain the first modified nano-silicon dioxide;

[0066] A2, take 350 g of the first modified nano-silica, add 800 ml of absolute ethanol, stir at 300 r / min and ultrasonic dispersion for 35 min, then add 1.5 g of azobisisobutyronitrile and continue to stir ultrasonically for 10 min, heat to 85℃ under nitrogen protection, slowly add 35 g of acrylic acid, after the addition is completed, heat at 500 r / min for 8 h, after the reaction is completed, naturally cool to room temperature, filter, wash with absolute ethanol 5 times, and then vacuum dry at 110℃ for 7 h to obtain the second modified nano-silica;

[0067] A3, take 300 g of the second modified nano-silica, add 700 ml of deionized water, stir at 300 r / min and ultrasonic dispersion for 30 min, then add 18 g of aluminum chloride and stir until dissolved, then slowly add 25% ammonia water by mass fraction to adjust the pH to 8.0, stir at room temperature at 500 r / min for 4 h; after the reaction is completed, centrifugal separation, the precipitate is washed with deionized water until the washing liquid does not produce white precipitate after adding silver nitrate solution, and then vacuum dry at 100℃ for 8 h to obtain the modified nano-silica.

[0068] Example 6, preparation of modified polyimide resin, the specific preparation steps are as follows:

[0069] B1, add 200 ml of N,N-dimethylformamide to a four-necked flask, add 30 g of m-phenylenediamine and 15 g of 4,4'-diamino diphenyl ether under nitrogen protection, stir at 400 r / min until dissolved, control the temperature at 0℃; add 40 g of pyromellitic dianhydride in 3 times, stir for 30 min after each addition, continue to stir for 2 h after the viscosity of the system reaches 5000 mPa・s, to obtain a copolymer type polyamide acid solution;

[0070] B2, add 500 ml of dimethylbenzene to 300 ml of the copolymer type polyamide acid solution, stir uniformly at 500 r / min to form a mixed system; add 8 g of maleic anhydride and 0.5 g of dicumyl peroxide, heat to 85℃ under nitrogen protection, stir and reflux for 4 h; after the reaction is completed, heat to 120℃, stir at 300 r / min for 2 h to complete the imidization process; after cooling to room temperature, filter, wash with dimethylbenzene 3 times, and then vacuum dry at 120℃ for 6 h to obtain the grafted modified polyimide resin;

[0071] B3, take 120 g of grafted modified polyimide resin, add 400 ml of ethanol / butyron mixed solvent with a volume ratio of 3:1, stir at 400 r / min until dissolved; add 15 g of epoxy resin E-51 and 2 g of triethylene tetramine, stir uniformly at 500 r / min, then heat to 60℃ and stir for 3 h, during which the gel time is measured every 1 h, and the reaction is stopped when the gel time is stable at 30 min; pour the solution into water to precipitate, filter, wash with ethanol for 3 times, and precipitate at 130℃ for 7 h under vacuum drying to obtain the modified polyimide resin.

[0072] Example 7, preparation of modified polyimide resin, the specific preparation steps are as follows:

[0073] B1, add 250 ml of N,N-dimethylformamide to a four-necked flask, add 40 g of m-phenylenediamine and 20 g of 4,4'-diamino diphenyl ether under nitrogen protection, stir at 400 r / min until dissolved, control the temperature at 5℃; add 50 g of pyromellitic dianhydride in 4 times, stir for 40 min after each addition, and continue to stir for 3 h after the viscosity of the system reaches 8000 mPa・s to obtain a copolymeric polyamic acid solution;

[0074] B2, add 600 ml of dimethylbenzene to 350 ml of the copolymeric polyamic acid solution, stir uniformly at 500 r / min to form a mixed system; add 12 g of maleic anhydride and 1 g of dicumyl peroxide, heat to 95℃ under nitrogen protection, and stir to reflux for 5 h; after the reaction is completed, heat to 130℃, and imidize at 300 r / min for 3 h to complete the imidization process; after cooling to room temperature, filter, wash with dimethylbenzene for 3 times, and then vacuum dry at 130℃ for 8 h to obtain the grafted modified polyimide resin;

[0075] B3, take 150 g of grafted modified polyimide resin, add 500 ml of ethanol / butyron mixed solvent with a volume ratio of 3:1, stir at 400 r / min until dissolved; add 20 g of epoxy resin E-51 and 3 g of triethylene tetramine, stir uniformly at 500 r / min, then heat to 70℃ and stir for 4 h, during which the gel time is measured every 1 h, and the reaction is stopped when the gel time is stable at 40 min; pour the solution into water to precipitate, filter, wash with ethanol for 3 times, and precipitate at 140℃ for 9 h under vacuum drying to obtain the modified polyimide resin.

[0076] Comparative Example 1, preparation of an insulation tape for new energy batteries, the specific preparation steps are as follows:

[0077] The remaining steps are unchanged, only the nano-silicon dioxide of Example 3 is replaced with the modified nano-silicon dioxide prepared in Example 4 to prepare an insulation tape for new energy batteries.

[0078] The comparative example 2 is to prepare the insulating adhesive tape for new energy battery, and the specific preparation steps are as follows:

[0079] The remaining steps are unchanged, only the polyimide resin of example 3 is replaced with the modified polyimide resin prepared in example 7, to prepare the insulating adhesive tape for new energy battery.

[0080] The comparative example 3 is to prepare the insulating adhesive tape for new energy battery, and the specific preparation steps are as follows:

[0081] The remaining steps are unchanged, only the nano-silicon dioxide of example 3 is replaced with the modified nano-silicon dioxide prepared in example 4, and the polyimide resin is replaced with the modified polyimide resin prepared in example 7, to prepare the insulating adhesive tape for new energy battery.

[0082] Performance test

[0083] ;

[0084] From the performance test results, the insulating adhesive tapes for new energy batteries of examples 1-3 all have certain volume resistivity, electrolyte resistance, tensile strength and temperature resistance, and the overall performance gradually improves with the optimization of raw material ratio and process parameters; while the comparative examples 1-3 use modified nano-silicon dioxide and modified polyimide resin, the performance of each is significantly better than that of the examples, among which the comparative example 3 uses both modified nano-silicon dioxide and modified polyimide resin, and the performance is the best, with room temperature and high temperature volume resistivity, electrolyte resistance after volume resistivity, respectively 2.8*10 15 Ω·cm, 2.1*10 15 Ω·cm, 2.6*10 15 Ω·cm, electrolyte resistance mass change rate only +0.7%, electrolyte resistance after tensile strength retention rate of 98%, tensile strength 35.6MPa, temperature resistance to thermal deformation temperature 190℃, flame retardant level V-0, which fully shows that the synergistic effect of modified nano-silicon dioxide and modified polyimide resin can greatly improve the insulation, electrolyte resistance, mechanical properties and high temperature resistance of the insulating adhesive tape.

[0085] The above content is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific examples or use similar ways to replace, as long as it does not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. An insulating tape for a new energy battery, characterized by: The new energy battery insulating tape is prepared from a pretreated glass fiber cloth coated with a coating, and the coating comprises the following raw materials in parts by weight: 15-20 parts of modified polyimide resin, 2-4 parts of epoxy resin E-51, 71-77 parts of ethanol / butanone mixed solvent, 3-5 parts of modified nano silicon dioxide, 0.2-0.4 parts of silane coupling agent KH-550, 0.1-0.3 parts of polydimethylsiloxane, 0.1-0.2 parts of paraffin-based mineral oil, and 0.3-0.5 parts of triethylene tetramine; the pretreated material of the glass fiber cloth comprises deionized water and a 5%-8% sodium hydroxide solution; The modified nano silicon dioxide is prepared according to the following steps: A1, take nano silicon dioxide, add deionized water to stir at 300 r / min and ultrasonic dispersion for 30-40 min, drop 0.1 mol / L hydrochloric acid to adjust pH to 4.0-4.5, then add polyvinyl alcohol-1788, stir at 500 r / min until dissolved, heat to 55-65℃ and stir for 1 h, then slowly drop silane coupling agent KH-570, and keep stirring and reacting for 5-6 h; after the reaction, stand for 2 h, then centrifugal separation, the precipitate is washed with deionized water until neutral, then washed with ethanol for 2 times, and vacuum dried at 85-95℃ for 7-9 h to obtain the first modified nano silicon dioxide; A2, take the first modified nano silicon dioxide, add anhydrous ethanol to stir at 300 r / min and ultrasonic dispersion for 25-35 min, then add azobisisobutyronitrile and continue to stir and ultrasonic for 5-10 min, heat to 75-85℃ under nitrogen protection, slowly drop acrylic acid, after dropping, keep stirring at 500 r / min for 7-8 h, after the reaction, naturally cool to room temperature, then filter, wash with anhydrous ethanol for 5 times, and vacuum dried at 100-110℃ for 5-7 h to obtain the second modified nano silicon dioxide; A3, take the second modified nano silicon dioxide, add deionized water to stir at 300 r / min and ultrasonic dispersion for 20-30 min, then add aluminum chloride and stir until dissolved, then slowly drop 25% ammonia water to adjust pH to 7.5-8.0, keep stirring at 500 r / min for 3-4 h at room temperature; after the reaction, centrifugal separation, the precipitate is washed with deionized water until the washing liquid has no white precipitate after adding silver nitrate solution, then vacuum dried at 90-100℃ for 6-8 h to obtain the modified nano silicon dioxide; The modified polyimide resin is prepared according to the following steps: B1, add N,N-dimethylformamide into a four-necked flask, add m-phenylenediamine and 4,4'-diamino diphenyl ether under nitrogen protection, stir at 400 r / min until dissolved, control the temperature at 0-5℃; add phthalic anhydride in 3-4 times, stir for 30-40 min after each addition, continue to stir and react for 2-3 h after the viscosity of the system reaches 5000-8000 mPa・s, to obtain a copolymerized polyamide acid solution; B2, adding xylene to the copolymerized polyamic acid solution, stirring uniformly at 500 r / min, forming a mixed system; adding maleic anhydride and dicumyl peroxide, heating to 85-95°C under nitrogen protection, stirring refluxing for 4-5h; after the reaction is completed, heating to 120-130°C, stirring for 2-3h at 300 r / min to complete the imidization process; after cooling to room temperature, filtering, washing 3 times with xylene, and then drying at 120-130°C under vacuum for 6-8h to obtain a grafted modified polyimide resin; B3, taking the grafted modified polyimide resin, adding a volume ratio of 3:1 of ethanol / butyron mixed solvent, stirring to dissolve at 400 r / min; adding epoxy resin E-51 and triethylenetetramine, stirring uniformly at 500 r / min, heating to 60-70°C, and stirring for 3-4h, during which the gel time is measured every 1h, and the reaction is stopped when the gel time is stable at 30-40min; pouring the solution into water to precipitate, filtering, washing 3 times with ethanol, and precipitating at 130-140°C under vacuum for 7-9h to obtain a modified polyimide resin.

2. The insulating tape for new energy batteries according to claim 1, characterized in that: The volume ratio of ethanol to butyron in the ethanol / butyron mixed solvent is 3:

1.

3. The insulating tape for new energy batteries according to claim 1, characterized in that: The amount ratio of nano-silicon dioxide, deionized water, polyvinyl alcohol-1788, and silane coupling agent KH-570 in A1 is 400-500g:800-1000ml:20-30g:25-35ml; The amount ratio of the first modified nano-silicon dioxide, anhydrous ethanol, azobisisobutyronitrile, and acrylic acid in A2 is 300-350g:700-800ml:0.8-1.5g:25-35g; The amount ratio of the second modified nano-silicon dioxide, deionized water, and aluminum chloride in A3 is 250-300g:600-700ml:12-18g.

4. The insulating tape for new energy batteries according to claim 1, characterized in that: The amount ratio of N,N-dimethylformamide, m-phenylenediamine, 4,4'-diamino diphenyl ether, and pyromellitic dianhydride in B1 is 200-250ml:30-40g:15-20g:40-50g; The amount ratio of the copolymerized polyamic acid solution, xylene, maleic anhydride, and dicumyl peroxide in B2 is 300-350ml:500-600ml:8-12g:0.5-1g; The amount ratio of the grafted modified polyimide resin, ethanol / butyron mixed solvent, epoxy resin E-51, and triethylenetetramine in B3 is 120-150g:400-500ml:15-20g:2-3g.

5. A method for preparing insulating tape for new energy batteries as described in claim 1, characterized in that: Specifically comprising the following steps: S1, placing the glass fiber cloth into deionized water, stirring at 300 r / min for 15min to remove surface dust and loose fibers, fishing out and draining; transferring into 5%-8% sodium hydroxide solution, stirring at 200 r / min for 20min at 60-70°C to activate the cloth surface; washing with deionized water until the pH is neutral, and then drying in an oven at 120-130°C for 2-3h, and cooling for standby; S2, take the modified polyimide resin, epoxy resin E-51, add to ethanol / butyron mixed solvent, stir at 50-60 DEG C under 400-600 r / min until the resin is completely dissolved, form clear transparent resin liquid; S3, take modified nanosilica, add ethanol / butyron mixed solvent and silane coupling agent KH-550, first stir at 800 r / min for 15 min, then ultrasonic dispersion pretreatment for 10-15 min; Then slowly add the pretreated modified nanosilica to the resin liquid of S2, stir at 1000-1200 r / min, continue to stir at high speed for 25-35 min after adding, then transfer into ice water bath environment and ultrasonic dispersion for 20-30 min, ensure that the nanosilica does not agglomerate; S4, add polydimethylsiloxane and paraffin-based mineral oil to the dispersion system of S3, adjust the stirring rate to 300-400 r / min, and stir at room temperature for 15-25 min to make the additives uniformly dispersed; Pass nitrogen, slowly add triethylene tetramine to the system, stir at 300-400 r / min for 15-20 min to ensure that the curing agent is completely integrated without obvious particles or stratification; S5, filter the prepared coating with 800-1000 mesh nylon filter screen, and let the filtered coating stand at room temperature for 30-60 min to naturally remove the residual small bubbles in the system, obtaining the insulating tape coating that can be used for coating; S6, lay the pretreated glass fiber cloth on the conveying belt of the coating machine, and uniformly coat the above-mentioned coating on both sides of the cloth with a coating thickness of 0.05-0.1 mm; after coating, send the substrate into the drying oven and process according to the ladder curing program: first dry at 90-95 DEG C for 25-35 min, then heat to 125-135 DEG C for 55-65 min, and finally heat to 175-185 DEG C for 110-130 min to fully complete the curing reaction and ensure the performance of the tape, such as high temperature resistance and electrolyte resistance, to obtain the insulating tape for new energy batteries.

6. The method for preparing the insulation tape for new energy batteries according to claim 5, characterized in that: The temperature of the ice water bath environment in S3 is controlled at 0-5 DEG C, the ultrasonic dispersion power is 300-500 W, and the stirring time is 30 s every 5 min during the ultrasonic process.

7. The method of claim 5, wherein the method further comprises the steps of: coating the adhesive layer with a protective layer; and coating the protective layer with a release layer. The coating speed of the coating machine in S6 is 1-2 m / min, and hot air assisted drying is used during the coating process, with a hot air temperature of 40-50 DEG C and a hot air speed of 1-1.5 m / s to prevent the coating from flowing and causing uneven thickness during the coating process, and to preliminarily remove part of the solvent.