Flexible disassembling adhesive for new energy automobile battery and preparation method of flexible disassembling adhesive

Abstract

The invention provides a new energy automobile battery flexible disassembling adhesive and a preparation method thereof, and belongs to the technical field of new energy automobile batteries, the flexible disassembling adhesive comprises the following components by weight: 45-50 parts of deionized water; 8 to 10 parts of gamma-butyrolactone; 5 to 8 parts of propylene glycol methyl ether acetate; 2 to 3 parts of microencapsulated lipase; 2 to 3 parts of nano cellulose immobilized protease; 6 to 8 parts of urea peroxide; 0.5 to 1 part of nano manganese dioxide; 0.7 to 1.1 parts of a sodium citrate / sodium lactate buffer solution; 1.5 to 2.5 parts of polyvinylpyrrolidone K30; 0.8 to 1.2 parts of hydroxypropyl methyl cellulose; 0.05 to 0.1 part of a graphene oxide nanosheet; 0.5 to 0.8 part of a benzotriazole derivative; 0.1 to 0.3 part of sodium molybdate; 6 to 8 parts of sorbitol; and 5-7 parts of ascorbic acid. The flexible disassembly adhesive solves the problems of low efficiency, serious environmental pollution, high safety risk and low material recovery rate in traditional battery disassembly.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle batteries, and in particular to a flexible disassembly adhesive for new energy vehicle batteries and a preparation method thereof. Background Art

[0002] As the global energy crisis and environmental pollution become increasingly serious, the new energy vehicle industry has developed rapidly and has become an important direction for the transformation and upgrading of the automobile industry. As the core component of new energy vehicles, the recycling and treatment of power batteries after their service life has become increasingly prominent. According to statistics, by 2025, my country's retired power batteries will reach about 250,000 tons. How to efficiently and environmentally friendly dispose of these waste batteries has become a problem that the industry needs to solve urgently.

[0003] At present, the disassembly of new energy vehicle batteries mainly adopts the following methods: mechanical crushing method: the battery is disassembled by physical crushing, but this method has problems such as high energy consumption, mixed materials, difficulty in sorting, low recovery rate, etc., and dust pollution and safety hazards are easily generated in the process; high temperature melting method: the battery components are melted and separated by high temperature, but this method has extremely high energy consumption and will produce harmful gases, causing secondary pollution to the environment; chemical leaching method: the use of strong acid, strong alkali and other corrosive chemical reagents for treatment. Although the separation effect is better, the reagents are highly toxic, posing a threat to the health of operators and the environment, and the cost of waste liquid treatment is high; traditional solvent method: organic solvents are used to dissolve the binder, but the solvents are highly volatile and toxic, and have poor adaptability to different types of batteries, and the treatment efficiency is low.

[0004] The above methods generally have the following technical problems: serious environmental pollution: traditional methods often produce a large amount of harmful gases, waste liquids and solid wastes, causing serious pollution to the environment; high safety risks: short circuits, fires and even explosions may occur during mechanical crushing, and there are also safety hazards during high-temperature melting and chemical leaching; low material recovery rate: existing technologies make it difficult to achieve efficient separation and recovery of battery materials, resulting in a large loss of valuable materials such as precious metals; high energy consumption and high cost: traditional methods generally have high energy consumption, large equipment investment, complex operation and poor economic benefits; poor adaptability: battery structures and materials of different types and manufacturers vary greatly, and existing technologies are difficult to adapt to diverse battery disassembly needs. Summary of the invention

[0005] The present invention provides a new energy vehicle battery flexible disassembly adhesive and a preparation method thereof, which are used to solve the technical problems of low battery disassembly efficiency, serious environmental pollution, high safety risk and low material recovery rate in the prior art.

[0006] The flexible disassembly adhesive for new energy vehicle batteries provided by the present invention comprises the following components and their weight percentages:

[0007] Deionized water, 45 - 50 parts;

[0008] γ - butyrolactone, 8 - 10 parts;

[0009] Propylene glycol methyl ether acetate, 5 - 8 parts;

[0010] Microencapsulated lipase, 2 - 3 parts;

[0011] Nanocellulose - immobilized protease, 2 - 3 parts;

[0012] Urea peroxide, 6 - 8 parts;

[0013] Nanomanganese dioxide, 0.5 - 1 part;

[0014] Sodium citrate / sodium lactate buffer solution, 0.7 - 1.1 parts;

[0015] Polyvinylpyrrolidone K30, 1.5 - 2.5 parts;

[0016] Hydroxypropyl methylcellulose, 0.8 - 1.2 parts;

[0017] Graphene oxide nanosheets, 0.05 - 0.1 part;

[0018] Benzotriazole derivative, 0.5 - 0.8 part;

[0019] Sodium molybdate, 0.1 - 0.3 part;

[0020] Sorbitol, 6 - 8 parts;

[0021] Ascorbic acid, 5 - 7 parts.

[0022] Preferably, the microencapsulated lipase is prepared by the following steps:

[0023] 1) Mix lipase and trehalose in a mass ratio of 1:1, dissolve as a solute in a phosphate buffer solution with a pH of 7.2, and the concentration is 20 - 25 mg / mL;

[0024] 2) Mix the solution prepared in step 1) with a 5% gelatin solution in a volume ratio of 4:1, and stir at a speed of 800 - 1000 rpm at 35 ± 2 °C for 15 - 20 minutes to form a primary emulsion;

[0025] 3) Add the primary emulsion obtained in step 2) to an aqueous solution containing 2% gum arabic, and stir at a speed of 1200 - 1500 rpm at 25 ± 2 °C for 30 minutes to form a stable emulsion;

[0026] 4) Spray - dry the emulsion prepared in step 3) under the conditions of an inlet temperature of 60 ± 2 °C, an outlet temperature of 35 ± 2 °C, a feeding rate of 8 - 10 mL / min, and an atomizing air pressure of 0.2 MPa to obtain microcapsules;

[0027] The D50 of the microcapsules is 2 - 5 μm, the particle size distribution index is < 0.3, the embedding efficiency is ≥ 85%, the wall-core ratio is 1:4 - 1:5, and the pH stable range is 4.5 - 9.0.

[0028] Preferably, in step 3), the volume ratio of the primary emulsion to the gum arabic solution is 1:4 to 1:5.

[0029] Preferably, the nano-cellulose immobilized protease is prepared by the following steps:

[0030] (1) Disperse TEMPO-oxidized nano-cellulose in a 0.1 M phosphate buffer solution with a pH of 7.0 at a concentration of 5 mg / mL;

[0031] (2) Mix a 50 mg / mL protease solution with the nano-cellulose suspension in step (1) at a volume ratio of 1:5, and stir at 4 ± 1 °C for 30 minutes;

[0032] (3) Slowly add a 0.5% glutaraldehyde solution to a final concentration of 0.1%, and stir and react at 4 ± 1 °C for 4 hours;

[0033] (4) Centrifuge and wash three times with a 0.1 M phosphate buffer solution with a pH of 7.0 to remove unbound enzymes;

[0034] (5) Treat with a buffer solution containing 1% glycine for 30 minutes to block unreacted aldehyde groups;

[0035] (6) After washing three times again, freeze-dry at -50 °C for 48 hours to obtain the immobilized enzyme;

[0036] The activity retention rate of the immobilized protease is ≥ 75%, the carrier loading is 80 - 100 mg enzyme / g carrier, the pH stable range is 5.0 - 8.5, the thermal stability is 2 times higher than that of the free enzyme at 60 °C, and the storage stability is that the activity loss is ≤ 10% in 30 days at 4 °C.

[0037] Preferably, the nano-manganese dioxide is prepared by the following steps:

[0038] Mix a 1 M KMnO4 solution and a 3 M ascorbic acid solution at a molar ratio of 1:1.5 at room temperature, and stir at a speed of 600 - 800 rpm;

[0039] After 5 minutes from the start of the reaction, slowly add a 1% citric acid solution, and the molar ratio of citric acid to KMnO4 is 1.5:1 as a stabilizer, and the dropping rate is controlled at 2 - 3 mL / min; at the same time, use a 0.5 M NaOH solution to adjust the pH to 7.0 ± 0.2 to ensure that the solution temperature is maintained at 25 ± 3 °C during the whole pH adjustment process;

[0040] After reacting for 30 to 40 minutes, centrifuge and separate, and wash with deionized water until neutral.

[0041] Ultrasonically disperse at a power of 200 W for 30 minutes to obtain stable nanoparticles.

[0042] Preferably, the nano manganese dioxide is spherical nanoparticles with a particle size distribution of 20 - 50 nm, a polydispersity index < 0.2, a specific surface area ≥ 100 m 2 / g, a Zeta potential ≤ -30 mV, a crystalline phase of δ-MnO2, and the catalytic decomposition rate of H2O2 is 3 times higher than that without catalysis, and the apparent activation energy is reduced by 40%.

[0043] Preferably, the benzotriazole derivative is methylbenzotriazole with a CAS number of 16584 - 00 - 2.

[0044] Preferably, the molar ratio of sodium citrate to sodium lactate in the sodium citrate / sodium lactate buffer solution is 1:1.2 - 1:1.5.

[0045] Preferably, the pH value of the flexible disassembly adhesive is 6.5 ± 0.2, the viscosity is 500 - 800 mPa·s, and the surface tension is 32 - 36 mN / m.

[0046] The preparation method of the flexible disassembly adhesive provided by the present invention includes the following steps:

[0047] a) Heat deionized water to 45 ± 2 °C, add polyvinylpyrrolidone K30, stir to dissolve, and disperse graphene oxide nanosheets under ultrasonic assistance;

[0048] b) Mix γ-butyrolactone and propylene glycol methyl ether acetate in a ratio of 1:1 under stirring, and add them to the suspension in step a);

[0049] c) Add hydroxypropyl methylcellulose, sorbitol, ascorbic acid, sodium citrate / sodium lactate buffer salt, benzotriazole derivative, and sodium molybdate in sequence, and stir evenly;

[0050] d) Dissolve urea peroxide in deionized water and slowly add it to the mixture in step c);

[0051] e) Add microencapsulated lipase, nanocellulose-immobilized protease, and nano manganese dioxide, and use a high-shear disperser to disperse evenly at a speed of 5000 - 6000 rpm for 3 minutes;

[0052] f) Adjust the pH to 6.5 ± 0.2, filter through a 5 μm filter membrane, degas at -0.05 MPa for 30 minutes, and fill it into an ultraviolet-proof container and seal it for storage

[0053] The present invention has the following beneficial effects:

[0054] (1) The flexible disassembly adhesive of the present invention uses microencapsulated lipase and nanocellulose-immobilized protease to form a biological catalytic synergistic degradation mechanism. Lipase can specifically recognize and hydrolyze the ester bond structure in the battery binder. By breaking these chemical bonds, the binder loses its adhesion ability. The microencapsulation technology endows lipase with an extremely wide pH stability range, effectively protecting the enzyme from strong oxidants in the disassembly environment; the protease immobilized on nanocellulose mainly hydrolyzes the peptide bonds and protein structures in the binder. The immobilization technology increases the thermal stability of the enzyme by 2 times compared with the free enzyme and the activity retention rate is ≥75%. At the same time, the large specific surface area of the nanocellulose carrier greatly enhances the contact efficiency with the binder; sorbitol stabilizes the three-dimensional conformation of the enzyme by constructing multiple hydrogen bonds, preventing the enzyme from denaturing and inactivating during the disassembly process. In addition, trehalose used in the microencapsulation process and sorbitol produce a synergistic protection effect, enabling the enzyme to maintain its activity in a wider temperature range.

[0055] (2) The urea peroxide, nano-manganese dioxide, and sodium molybdate used in the present invention have a synergistic catalytic effect. Urea peroxide, as a peroxide precursor, slowly releases H2O2 under specific conditions, providing continuous oxidation ability; nano-manganese dioxide particles with a δ-MnO2 crystal phase catalyze the decomposition of H2O2 to generate reactive oxygen species ·OH and ·O2 - , this catalytic effect increases the decomposition rate of H2O2 by 3 times and reduces the apparent activation energy by 40%, enabling the reaction to proceed rapidly under milder conditions; sodium molybdate, as a transition metal catalyst, forms a bimetallic catalytic system with nano-manganese dioxide, further enhancing the efficiency of the redox reaction.

[0056] (3) The solvents used in the present invention are γ-butyrolactone and propylene glycol methyl ether acetate. These two organic solvents are mixed in a ratio of 1:1 and have strong penetrability and solubility. They can penetrate into the interface between the electrode material and the current collector, soften the binder, and precisely control the surface tension of the adhesive within the range of 32 - 36 mN / m, enabling better wetting of the internal structure of the battery and enhancing the contact area with the binder; two polymers, polyvinylpyrrolidone K30 and hydroxypropyl methylcellulose, synergistically regulate the rheology of the adhesive, ensuring that the viscosity of the adhesive is 500 - 800 mPa·s, which can not only flow well and penetrate into the battery interior but also form a uniform covering layer on the vertical surface.

[0057] (4) Through the antioxidant effect of ascorbic acid, the present invention inhibits the excessive exothermic decomposition of peroxides, controls the reaction heat, and prevents thermal runaway caused by temperature rise; the structure of nano-manganese dioxide provides uniform catalytic active sites, ensuring that the oxidation reaction proceeds at a controllable rate and increasing the mildness and safety of the reaction.

[0058] (5) The present invention forms a protective adsorption layer on the metal surface by using benzotriazole derivatives, effectively preventing the corrosion of current collector metals such as copper and aluminum by oxidants and acidic substances; graphene oxide nanosheets can form a protective coating on the surface of the electrode material to prevent strong oxidants from directly acting on the crystal lattice of the active material, thereby maintaining the crystal structure integrity of the cathode material.

[0059] (6) The flexible disassembly adhesive for new energy vehicle batteries of the present invention can achieve efficient separation of battery materials under mild conditions by means of multiple synergistic mechanisms such as biocatalytic, chemical redox, and physical solvent penetration. Its precise microenvironment regulation and multi-level protection mechanism ensure the integrity and safety of materials during the disassembly process, opening up a revolutionary technical path for the recycling of new energy vehicle batteries. Detailed implementation manners

[0060] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0061] In the embodiments of the present invention, the deionized water was purchased from Sigma-Aldrich, CAS No. 7732-18-5; γ-butyrolactone was purchased from Aladdin, CAS No. 96-48-0; propylene glycol methyl ether acetate was purchased from TCI, CAS No. 108-65-6; urea peroxide was purchased from Sigma-Aldrich, CAS No. 124-43-6; nano-manganese dioxide was purchased from Sigma-Aldrich, preferably the δ-MnO2 crystalline phase; sodium citrate was purchased from Sigma-Aldrich, CAS No. 6132-04-3; sodium lactate was purchased from Fisher Scientific, CAS No. 72-17-3; polyvinylpyrrolidone K30 was purchased from BASF, CAS No. 9003-39-8; hydroxypropyl methylcellulose was purchased from Dow Chemical, CAS No. 9004-65-3; graphene oxide nanosheets were purchased from Graphene Supermarket; methylbenzothiazole was purchased from TCI, CAS No. 16584-00-2; sodium molybdate was purchased from Alfa Aesar, CAS No. 7631-95-0; sorbitol was purchased from Sigma-Aldrich, CAS No. 50-70-4; ascorbic acid was purchased from Sigma-Aldrich, CAS No. 50-81-7;

[0062] The microencapsulated lipase used is prepared by the following method: Mix lipase and trehalose in a mass ratio of 1:1, dissolve them in a phosphate buffer solution with a pH of 7.2 to make a solution with a concentration of 25 mg / mL. Mix the solution with a 5% gelatin solution in a volume ratio of 4:1, and stir at 1000 rpm for 20 minutes at 35°C to form a primary emulsion. Add the primary emulsion to a 2% aqueous arabic gum solution, with a volume ratio of 1:4, and stir at 1500 rpm for 30 minutes at 25°C to form a stable emulsion. Spray-dry the stable emulsion under the conditions of an inlet temperature of 60°C, an outlet temperature of 35°C, a feeding rate of 10 mL / min, and an atomization air pressure of 0.2 MPa to obtain the microencapsulated lipase.

[0063] The nano-cellulose immobilized protease used is prepared by the following method: Disperse TEMPO-oxidized nano-cellulose in a 0.1 M phosphate buffer solution with a pH of 7.0 to make a suspension with a concentration of 5 mg / mL. Mix a 50 mg / mL protease solution with the nano-cellulose suspension in a volume ratio of 1:5, stir at 4°C for 30 minutes, slowly add a 0.5% glutaraldehyde solution to a final concentration of 0.1%, stir and react at 4°C for 4 hours, wash three times by centrifugation with a 0.1 M phosphate buffer solution with a pH of 7.0, treat with a buffer solution containing 1% glycine for 30 minutes to block the unreacted aldehyde groups, and after washing three times, freeze-dry at -50°C for 48 hours to obtain the immobilized enzyme.

[0064] The TEMPO-oxidized nano-cellulose used is purchased from Nanjing Tianlu Nano Technology Co., Ltd., with a fiber diameter of 10 - 20 nm.

[0065] Example 1

[0066] This example provides a preparation method of a flexible disassembly adhesive for new energy vehicle batteries.

[0067] S1: Take 45 parts of deionized water, heat it to 44°C, add 1.5 parts of polyvinylpyrrolidone K30, stir until completely dissolved, and then disperse 0.05 parts of graphene oxide nanosheets under ultrasonic assistance with a power of 200 W and a frequency of 40 kHz for 10 minutes to obtain a uniform suspension.

[0068] S2: Under stirring at a rotation speed of 300 rpm, mix 8 parts of γ-butyrolactone and 5 parts of propylene glycol methyl ether acetate evenly in a mass ratio of 1:1, and then slowly add the suspension obtained in step a, and stir for 5 minutes.

[0069] S3: Add 0.8 parts of hydroxypropyl methylcellulose, 6 parts of sorbitol, 5 parts of ascorbic acid, 0.7 parts of sodium citrate / sodium lactate buffer solution, 0.5 parts of benzothiazole derivative, and 0.1 parts of sodium molybdate in sequence, and keep stirring at a rotation speed of 400 rpm for 10 minutes.

[0070] S4: Dissolve 6 parts of urea peroxide in 10 parts of deionized water. After preparing the solution, slowly add it dropwise to the mixture in step c at a rate of 1 mL / min, and keep stirring during the dropping process.

[0071] S5: Add 2 parts of microencapsulated lipase, 2 parts of nanocellulose-immobilized protease, and 0.5 part of nanomanganese dioxide, and disperse them for 3 minutes at a rotational speed of 5000 rpm using a high-shear disperser.

[0072] S6: Adjust the pH of the mixture to 6.5 using 0.5 M NaOH or citric acid solution, then filter it through a 5-μm filter membrane, degas it under a vacuum condition of -0.05 MPa for 30 minutes, and finally fill it into an ultraviolet-proof sealed container for storage to obtain the flexible disassembly adhesive for new energy vehicle batteries.

[0073] Example 2

[0074] This example provides a preparation method of a flexible disassembly adhesive for new energy vehicle batteries

[0075] S1: Take 50 parts of deionized water, heat it to 44 °C, add 2.5 parts of polyvinylpyrrolidone K30, stir until completely dissolved, and then disperse 0.1 part of graphene oxide nanosheets under ultrasonic assistance with a power of 200 W and a frequency of 40 kHz for 10 minutes to obtain a uniform suspension.

[0076] S2: Under stirring at a rotational speed of 300 rpm, mix 10 parts of γ-butyrolactone and 8 parts of propylene glycol methyl ether acetate evenly according to a mass ratio of 1:1, then slowly add them to the suspension obtained in step S1, stir for 5 minutes, and successively add 1.2 parts of hydroxypropyl methylcellulose, 8 parts of sorbitol, 7 parts of ascorbic acid, 1.1 parts of sodium citrate / sodium lactate buffer solution, 0.8 part of benzothiazole derivative, and 0.3 part of sodium molybdate, and keep stirring at a rotational speed of 400 rpm for 10 minutes.

[0077] S4: Dissolve 8 parts of urea peroxide in 10 parts of deionized water. After preparing the solution, slowly add it dropwise to the mixture in step S3 at a rate of 1 mL / min, and keep stirring during the dropping process.

[0078] S5: Add 3 parts of microencapsulated lipase, 3 parts of nanocellulose-immobilized protease, and 1 part of nanomanganese dioxide, and disperse them for 3 minutes at a rotational speed of 5000 - 6000 rpm using a high-shear disperser.

[0079] S6: Adjust the pH of the mixture to 6.4 using 0.5 M NaOH or citric acid solution, filter it through a 5-μm filter membrane, degas it under a vacuum condition of -0.05 MPa for 30 minutes, and finally fill it into an ultraviolet-proof sealed container for storage to obtain the flexible disassembly adhesive for new energy vehicle batteries.

[0080] Example 3

[0081] This example provides a preparation method for a flexible disassembly adhesive for new energy vehicle batteries

[0082] S1: Take 48 parts of deionized water, heat it to 45 °C, add 2.0 parts of polyvinylpyrrolidone K30, stir until completely dissolved, and then disperse 0.08 parts of graphene oxide nanosheets under ultrasonic assistance with a power of 200 W and a frequency of 40 kHz for 10 minutes to obtain a uniform suspension

[0083] S2: Under stirring at a rotation speed of 300 rpm, mix 9 parts of γ-butyrolactone and 6 parts of propylene glycol methyl ether acetate evenly according to a mass ratio of 1:1, and then slowly add them to the suspension obtained in step S1 and stir for 5 minutes

[0084] S3: Add 1.0 part of hydroxypropyl methylcellulose, 7 parts of sorbitol, 6 parts of ascorbic acid, 0.9 part of sodium citrate / sodium lactate buffer solution, 0.6 part of benzothiazole derivative, and 0.2 part of sodium molybdate in sequence, and keep stirring at a rotation speed of 400 rpm for 10 minutes

[0085] S4: Dissolve 7 parts of urea peroxide in 10 parts of deionized water to prepare a solution, and then slowly drip it into the mixture in step S3 at a rate of 1 mL / min while keeping stirring

[0086] S5: Add 2.5 parts of microencapsulated lipase, 2.5 parts of nanocellulose-immobilized protease, and 0.8 part of nanomanganese dioxide, and use a high-shear disperser to disperse at a rotation speed of 5500 rpm for 3 minutes

[0087] S6: Use 0.5 M NaOH or citric acid solution to adjust the pH of the mixture to 6.7, filter through a 5 μm filter membrane, degas under a vacuum condition of -0.05 MPa for 30 minutes, and finally fill it into an ultraviolet-resistant sealed container for storage to obtain a flexible disassembly adhesive for new energy vehicle batteries

[0088] Comparative Example 1

[0089] The formulation of this example is the same as that of Example 3, but the microencapsulated lipase is replaced with an equal amount of free lipase, and the other steps remain unchanged

[0090] Comparative Example 2

[0091] The formulation of this example is the same as that of Example 3, but nano manganese dioxide is not added, and the proportions of other components remain unchanged

[0092] Performance testing

[0093] pH value determination

[0094] Use a Mettler Toledo FE28 precision pH meter and perform three-point calibration using standard buffer solutions with pH values of 4.01, 7.00, and 10.01. Adjust the sample to 25°C in a constant temperature water bath. Take 20 mL of the sample and place it in a 50 mL beaker. Insert the pH electrode, and after the reading stabilizes for 30 seconds, record the value. Measure each sample 3 times and take the average. The test results are shown in Table 1.

[0095] Table 1 pH value measurement results

[0096] Sample Measurement Value 1 Measurement Value 2 Measurement Value 3 Average Value Example 1 6.42 6.45 6.47 6.45 Example 2 6.38 6.4 6.42 6.4 Example 3 6.68 6.72 6.7 6.7 Comparative Example 1 6.65 6.68 6.72 6.68 Comparative Example 2 6.75 6.73 6.69 6.72

[0097] Viscosity measurement

[0098] Use a Brookfield LVDV-II+Pro rotational viscometer. Select the No. 4 rotor according to the estimated viscosity and set the rotation speed to 30 rpm. Heat the sample to 25°C in a constant temperature water bath and let it equilibrate for 20 minutes. Place 100 mL of the sample in a standard measuring cup, insert the rotor to the marked line, start the measurement, and record the data after the reading stabilizes after 5 minutes, as shown in Table 2.

[0099] Table 2 Viscosity measurement data

[0100]

[0101]

[0102] Surface tension measurement

[0103] Use a KRüSS K20 du Noüy ring method surface tensiometer. Burn and clean the platinum-iridium alloy ring in a flame and then let it cool. Control the temperature of the sample to 25°C. Add 50 mL of the sample to a clean glass petri dish, adjust the measurement ring to contact the liquid surface, slowly lift it, and record the force value when the ring separates from the liquid surface. Convert it to surface tension. Measure each sample 5 times and take the average to obtain the data shown in Table 3.

[0104] Table 3 Surface tension measurement data

[0105] Sample Measurement Value (mN / m) Average Value (mN / m) Example 1 34.2,34.5,34.0,34.3,34.1 34.2 Example 2 33.8,33.5,33.7,33.9,34.0 33.8 Example 3 32.7,32.5,32.9,32.6,32.8 32.7 Comparative Example 1 33.0,32.8,33.1,33.0,32.9 33 Comparative Example 2 34.2,34.5,34.3,34.0,34.2 34.2

[0106] Determination of lipase activity retention rate

[0107] Mix 3 g of olive oil, 100 mL of distilled water, and 10 g of gum arabic, homogenize for 10 minutes at 12,000 rpm. Take 4 mL of the solution with equivalent enzyme content from each example and comparative example sample, place it in a constant temperature water bath at 60 °C for 1 hour. Under the condition of 37 °C, mix the treated enzyme solution with an equal volume of olive oil emulsion, react for 30 minutes, then add 10 mL of an ethanol-acetone 1:1 equal volume mixed solution to terminate the reaction. Titrate the free fatty acids with 0.05 M NaOH, using phenolphthalein as an indicator. At the same time, set the same enzyme solution without heat treatment as the control group, and the test results are shown in Table 4;

[0108] The retention rate of enzyme activity (%) = (enzyme activity after heat treatment / enzyme activity before heat treatment) × 100%.

[0109] Table 4 Determination results of lipase activity retention rate

[0110]

[0111] Determination of H2O2 decomposition efficiency

[0112] Design a gas collection device, including a reaction flask, a gas collection tube, and a graduated cylinder. Add 25 mL of 10% H2O2 solution to the reaction flask, quickly add 2 mL of each sample solution, seal immediately, record the amount of oxygen generated at 0, 5, 10, 15, and 20 minutes, calculate the catalytic reaction rate, with the unit of oxygen release amount in the initial 5 minutes / time. Compare with the blank control group and calculate the improvement multiple of the catalytic rate. The test results are shown in Table 5.

[0113] Table 5 Determination results of H2O2 decomposition efficiency

[0114]

[0115]

[0116] Battery disassembly efficiency test

[0117] Prepare a 18650 model battery module, pre-discharge it to 0 V, use a grinding wheel to cut open the battery top cover to expose the internal winding core. Uniformly coat 20 mL of the adhesive on the surface of the battery winding core, place the sample in an incubator at 40 °C, check it every 5 minutes, gently pull it with forceps, and test whether the separator and the electrode start to separate. Record the complete separation time, that is, the time point when the electrode and the separator can be completely separated without damaging the material with forceps. The test results are shown in Table 6.

[0118] Table 6 Test results of battery disassembly efficiency

[0119] Sample Starting Separation Time (min) Complete Separation Time (min) Example 1 12 25 Example 2 15 28 Example 3 18 30 Comparative Example 1 32 52 Comparative Example 2 25 43

[0120] Temperature cycle stability test

[0121] The samples were aliquoted into sealed containers for temperature cycling tests: maintained at -10°C for 2 hours, transitioned to room temperature for 1 hour, maintained at 50°C for 2 hours, and transitioned to room temperature for 1 hour; the above cycle was repeated 5 times, and the changes in pH, viscosity, and dispersion stability before and after the cycle were measured. The test results are shown in Table 7.

[0122] Table 7 Test Results of Temperature Cycling Stability

[0123] Sample Layering Phenomenon Precipitation Phenomenon pH Change Viscosity Change (%) Example 1 None Slight 0.2 -6.8 Example 2 None Slight 0.3 -7.5 Example 3 None None 0.2 -5.2 Comparative Example 1 Obvious Severe 0.8 -18.6 Comparative Example 2 Slight Moderate 0.5 -12.3

[0124] Data Analysis

[0125] As can be seen from Table 1, the pH values of all groups are in the range of 6.38 - 6.75, showing weak acidity.

[0126] As can be seen from Table 2, the overall viscosity of the samples containing nano-manganese dioxide is higher than that of Comparative Example 2 without nano-manganese dioxide.

[0127] As can be seen from Table 3, there is little difference in surface tension between the comparative examples and the examples.

[0128] As can be seen from Table 4, the activity retention rates of Examples 1 - 3 are all 92% - 92.5%, showing excellent thermal stability. The activity retention rate of Comparative Example 1 is only 42.9%, indicating that microencapsulated lipase significantly improves the thermal stability of the enzyme, increasing the activity retention rate by about 50%.

[0129] As can be seen from Table 5, compared with Comparative Example 2, the catalytic enhancement multiples of Examples 1 - 3 are 3.8, 3.6, and 3.4 times respectively, indicating that the addition of nano-manganese dioxide significantly improves the decomposition efficiency of H2O2, about 3.4 - 3.8 times.

[0130] As can be seen from Table 6, the complete separation times of Examples 1 - 3 are 25, 28, and 30 minutes respectively, and the complete separation times of Comparative Examples 1 - 2 are 52 and 43 minutes respectively. The disassembly efficiency of the formulation containing nano-manganese dioxide is significantly higher than that of the comparative formulation, and the disassembly efficiency of the microencapsulated lipase formulation is about 42% higher than that of the free lipase formulation.

[0131] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention application shall still fall within the scope covered by the patent of the present invention.

Claims

1. A flexible disassembly adhesive for new energy vehicle batteries, characterized in that, The flexible disassembly adhesive comprises the following components and their weight percentages: Deionized water, 45 - 50 parts; γ-butyrolactone, 8 - 10 parts; Propylene glycol methyl ether acetate, 5 - 8 parts; Microencapsulated lipase, 2 - 3 parts; Nanocellulose-immobilized protease, 2 - 3 parts; Urea peroxide, 6 - 8 parts; Nanomanganese dioxide, 0.5 - 1 part; Sodium citrate / sodium lactate buffer solution, 0.7 - 1.1 parts; Polyvinylpyrrolidone K30, 1.5 - 2.5 parts; Hydroxypropyl methylcellulose, 0.8 - 1.2 parts; Graphene oxide nanosheets, 0.05 - 0.1 part; Benzotriazole derivative, 0.5 - 0.8 part; Sodium molybdate, 0.1 - 0.3 part; Sorbitol, 6 - 8 parts; Ascorbic acid, 5 - 7 parts.

2. The flexible disassembly adhesive according to claim 1, wherein, The microencapsulated lipase is prepared by the following steps: 1) Mix lipase and trehalose at a mass ratio of 1:1, dissolve as a solute in a phosphate buffer solution with a pH of 7.2, and the concentration is 20 - 25 mg / mL; 2) Mix the solution prepared in step 1) with a 5% gelatin solution at a volume ratio of 4:1, and stir at a speed of 800 - 1000 rpm at 35 ± 2 °C for 15 - 20 minutes to form a primary emulsion; 3) Add the primary emulsion obtained in step 2) to an aqueous solution containing 2% gum arabic, and stir at a speed of 1200 - 1500 rpm at 25 ± 2 °C for 30 minutes to form a stable emulsion; 4) Spray-dry the emulsion prepared in step 3) under the conditions of an inlet temperature of 60 ± 2 °C, an outlet temperature of 35 ± 2 °C, a feeding rate of 8 - 10 mL / min, and an atomizing air pressure of 0.2 MPa to obtain microcapsules; The microcapsules have a particle size D50 of 2 - 5 μm, a particle size distribution index < 0.3, an embedding efficiency ≥ 85%, a wall-core ratio of 1:4 - 1:5, and a pH stable range of 4.5 - 9.

0.

3. The flexible disassembly adhesive according to claim 2, wherein, In step 3), the volume ratio of the primary emulsion to the gum arabic solution is 1:4 to 1:

5.

4. The flexible disassembly adhesive according to claim 1, wherein The nanocellulose-immobilized protease is prepared by the following steps: (1) Disperse TEMPO-oxidized nanocellulose in a 0.1 M phosphate buffer solution with a pH of 7.0, and the concentration is 5 mg / mL; (2) Mix a 50 mg / mL protease solution with the nanocellulose suspension in step (1) at a volume ratio of 1:5, and stir at 4 ± 1 °C for 30 minutes; (3) Slowly add a 0.5% glutaraldehyde solution to a final concentration of 0.1%, and stir and react at 4 ± 1 °C for 4 hours; (4) Centrifuge and wash three times with a 0.1 M phosphate buffer solution with a pH of 7.0 to remove unbound enzyme; (5) Treat with a buffer solution containing 1% glycine for 30 minutes to block unreacted aldehyde groups; (6) After washing three times again, freeze-dry at -50 °C for 48 hours to obtain the immobilized enzyme; The activity retention rate of the immobilized protease ≥ 75%, the carrier loading is 80 - 100 mg enzyme / g carrier, the pH stable range is 5.0 - 8.5, the thermal stability is 2 times higher than that of the free enzyme at 60 °C, and the storage stability is that the activity loss ≤ 10% in 30 days at 4 °C.

5. The flexible disassembly adhesive according to claim 1, wherein, The nano manganese dioxide is prepared by the following steps: Mix a 1M KMnO4 solution and a 3M ascorbic acid solution at a molar ratio of 1:1.5 at room temperature with a stirring speed of 600 - 800 rpm; After 5 minutes from the start of the reaction, slowly add a 1% citric acid solution with a molar ratio of citric acid to KMnO4 of 1.5:1 as a stabilizer, and control the dropping rate at 2 - 3 mL / min; at the same time, use a 0.5M NaOH solution to adjust the pH to 7.0 ± 0.2, ensuring that the solution temperature is maintained at 25 ± 3 °C during the whole pH adjustment process; After reacting for 30 - 40 minutes, perform centrifugal separation and wash with deionized water until neutral; Perform ultrasonic dispersion at a power of 200W for 30 minutes to obtain stable nanoparticles.

6. The flexible disassembly adhesive according to claim 5, wherein The nano-manganese dioxide is spherical nanoparticles with a particle size distribution of 20-50 nm, a polydispersity index < 0.2, a specific surface area ≥ 100 m 2 / g, a Zeta potential ≤ -30 mV, a crystal phase of δ-MnO2, a catalytic decomposition rate of H2O2 3 times higher than that without catalysis, and an apparent activation energy reduced by 40%.

7. The flexible disassembly adhesive according to claim 1, wherein The benzotriazole derivative is methylbenzotriazole, and the CAS number is 16584 - 00 - 2.

8. The flexible disassembly adhesive according to claim 1, wherein In the sodium citrate / sodium lactate buffer solution, the molar ratio of sodium citrate to sodium lactate is 1:1.2 - 1:1.

5.

9. The flexible disassembly adhesive according to claim 1, wherein The pH value of the flexible disassembling adhesive is 6.5 ± 0.2, the viscosity is 500 - 800 mPa·s, and the surface tension is 32 - 36 mN / m.

10. A method for preparing the flexible disassembly adhesive according to any one of claims 1-9, characterized in that, It includes the following steps: a) Heat deionized water to 45 ± 2 °C, add polyvinylpyrrolidone K30, stir to dissolve, and disperse graphene oxide nanosheets under ultrasonic assistance; b) Mix γ-butyrolactone and propylene glycol methyl ether acetate at a ratio of 1:1 under stirring and add them to the suspension in step a); c) Add hydroxypropyl methylcellulose, sorbitol, ascorbic acid, sodium citrate / sodium lactate buffer salt, benzotriazole derivative, and sodium molybdate in sequence and stir evenly; d) Dissolve urea peroxide in deionized water and slowly add it to the mixture in step c); e) Add microencapsulated lipase, nanocellulose-immobilized protease, and nano manganese dioxide, and use a high-shear disperser to disperse evenly at a rotation speed of 5000 - 6000 rpm for 3 minutes; f) Adjust the pH to 6.5 ± 0.2, filter through a 5μm filter membrane, degas at -0.05 MPa for 30 minutes, and fill it into an ultraviolet-resistant container and seal for storage.

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