High-performance packaging material for vehicle energy storage system and packaging process

Abstract

The invention relates to the technical field of new energy automobile materials, in particular to a high-performance packaging material for an automobile energy storage system and a packaging technology, and the packaging material for the automobile energy storage system comprises the following components: an organic silicon-carbon nanotube-graphene-MOF hybrid polymer containing rare earth elements; a lithium salt-ionic liquid compound is loaded on the hollow titanium dioxide microspheres; a phosphorus-silicon-boron containing synergistic flame retardant; the invention discloses an intelligent phase change microcapsule-carbon dot composite material. A difunctional ionic liquid plasticizer; a photocatalysis-photothermal antibacterial agent; a two-dimensional boron nitride nanosheet; the invention relates to bio-based PLGA. Through multi-component cooperation and process innovation, high thermal conductivity, strong flame retardance and excellent mechanical properties are achieved, the rare earth hybrid polymer improves interface bonding, and MOF channels promote ion transmission; the phosphorus-silicon-boron flame-retardant system forms a glassy protective layer; the bio-based PLGA improves the degradation rate; the magnetic field induction and pulse hot pressing process optimizes the filler arrangement and density, and ensures the stability of large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle materials, and specifically to a high-performance encapsulation material and an encapsulation process for a vehicle energy storage system. Background Art

[0002] With the rapid development of new energy vehicles and renewable energy technologies, vehicle energy storage systems have put forward more stringent performance requirements for encapsulation materials. Traditional encapsulation materials mostly use single matrices such as epoxy resins and polyolefins, which have prominent problems such as low thermal conductivity, insufficient flame retardancy, and poor environmental responsiveness. Especially under extreme working conditions, combustion accidents caused by thermal runaway occur frequently, seriously threatening the safety of in-vehicle energy storage systems. In the prior art, although attempts have been made to modify by adding functional fillers such as carbon nanotubes and intumescent flame retardants, there are many technical bottlenecks. Single fillers are difficult to simultaneously meet the comprehensive requirements of thermal conductivity, flame retardancy, mechanics, and environmental adaptability. For example, although graphene can improve thermal conductivity, excessive addition will increase the brittleness of the material; the addition amount of traditional flame retardants needs to be >30% to reach the UL94 V-0 level, but it will significantly deteriorate the mechanical properties of the material. In addition, the contradiction between ion migration inside the energy storage system and the interfacial compatibility of the material has not been effectively solved.

[0003] Existing materials lack the intelligent response ability to external stimuli such as temperature and stress. Although phase change materials can achieve thermal energy storage, conventional microcapsule wall materials have poor thermal stability and low phase change enthalpy, and cannot meet the thermal management requirements under fast charge and discharge conditions. The traditional melt blending method is prone to uneven dispersion of fillers and many interfacial defects; the orientation degree of fillers is low during the molding process, and it is difficult to construct an anisotropic thermal conduction network. Research shows that when the orientation degree of thermal conductive fillers is increased from random distribution to 90%, the in-plane thermal conductivity of the material can be increased by 3-5 times, but the existing magnetic field / electric field induction technologies have problems such as high energy consumption and complex processes.

[0004] Petroleum-based polymers are difficult to degrade, while bio-based materials have defects such as low heat distortion temperature and poor compatibility with inorganic fillers. At the same time, microorganisms are likely to grow on the surface of encapsulation materials, and traditional silver-based antibacterial agents have problems such as easy oxidation and inactivation and low photocatalytic efficiency.

[0005] In response to the above problems, in recent years, the academic community has carried out explorations on multi-scale composite materials: for example, using MOF / graphene hybrid structures to improve ion transport efficiency, using hollow microspheres to load lithium salts to optimize interfacial ion distribution, and constructing a high-temperature protection layer through a phosphorus-silicon-boron synergistic flame retardant system. However, these technologies are mostly limited to the laboratory stage and have not formed a systematic material design and process integration scheme. Especially under the special working conditions of vehicle energy storage systems, the existing material systems still have defects such as fast performance decay and short life cycle. Summary of the Invention

[0006] (1) Technical problems to be solved In view of the deficiencies of the prior art, the present invention provides a high-performance encapsulation material and an encapsulation process for a vehicle energy storage system.

[0007] (2) Technical solutions A high-performance encapsulation material for a vehicle energy storage system, which is composed of the following components in parts by weight: 30-50 parts of a rare earth element-containing organosilicon-carbon nanotube-graphene-MOF hybrid polymer, and its synthesis reaction is carried out in three steps: The first step is the silylation of graphene oxide: The second step is the in-situ growth of MOF: The third step is hybrid polymerization: 15-25 parts of a lithium salt-ionic liquid composite supported by hollow titanium dioxide microspheres, and the preparation process: Preparation of microspheres by the template method: Loading of lithium salt: Anchoring of ionic liquid: 10-15 parts of a phosphorus-silicon-boron synergistic flame retardant, and the synthesis reaction formula is: The molar ratio of phosphorus: silicon: boron is 1.5:1:0.8, and a glassy composite protective layer is formed during combustion, and the limiting oxygen index reaches 34%; 5-10 parts of an intelligent phase change microcapsule-carbon dot composite material, the carbon dots are synthesized by a hydrothermal method, glucose and ethylenediamine are reacted in an autoclave at 180 °C for 2 h to obtain N-doped carbon dots with a particle size of 3-5 nm; the microcapsules are prepared by an in-situ polymerization method, and the carbon dots are embedded in the polyurea-polyurethane wall material at a ratio of 10 wt%, and the phase change enthalpy of the composite material reaches 120 J / g, and the response time ≤ 15 s; 3-8 parts of a bifunctional ionic liquid plasticizer, 1-butyl-3-methylimidazolium chloride and lithium bis(trifluoromethanesulfonyl)imide are reacted in an acetone solvent at an equimolar ratio at 60 °C for 8 hours to generate the target ionic liquid; the glass transition temperature of the ionic liquid encapsulation material drops from -40 °C to -80 °C, and at the same time, the ionic conductivity at 25 °C is achieved ; 1-3 parts of a photocatalytic-photothermal antibacterial agent, and a core-shell structure is constructed by a two-step method, and the nano ​The particles are dispersed in a silver nitrate solution and reduced by ultraviolet light irradiation and sodium borohydride to form a core layer of Ag nanoparticles with a particle size of 5-10 nm. Then, a copper sulfide layer is deposited on the surface by the aqueous precipitation method, and the reaction conditions are controlled to accurately regulate the thickness of the CuS layer to 8 nm. Active oxygen species are generated under visible light to destroy the bacterial cell wall. The CuS layer rapidly heats up to 60 °C under 850 nm laser irradiation, and the thermal effect kills microorganisms. The killing rate of Escherichia coli reaches 99.9% after 30 minutes of light irradiation. 0.5-2 parts of two-dimensional boron nitride nanosheets are prepared by the ultrasonic exfoliation method. Bulk boron nitride and N,N-dimethylformamide are mixed at a mass ratio of 1:10 and treated at an ultrasonic power of 200 W for 4 h to obtain BN nanosheets with a thickness of 6-12 nm and a lateral size of 2-5 μm. These nanosheets increase the thermal conductivity of the encapsulating material from 0.8 to 3.5 After modification with the silane coupling agent KH560, the contact angle decreases from 85° to 40°. 3-5 parts of bio-based PLGA are synthesized by ring-opening polymerization. Lactic acid (LA) and glycolic acid (GA) are mixed at a molar ratio of 75:25, and 0.8 wt% stannous octoate is added as a catalyst. The reaction is carried out at 140 °C under nitrogen protection for 24 h to produce a random copolymer with a weight-average molecular weight of 55 kDa. Preferably, the synthesis process of the rare earth element-containing organosilicon-carbon nanotube-graphene-MOF hybrid polymer includes: refluxing GO and KH570 in toluene at a mass ratio of 1:3, and detecting the characteristic peak of the Si-O-C bond at 1100 by FTIR; growing MIL-101(Cr) on the surface of GO by the solvothermal method, and showing the characteristic peaks of MOF at 2θ = 9.5° and 19.0° in the XRD pattern; promoting the coordination reaction between Ce³⁺ and Si-OH under microwave assistance, and confirming the formation of the Ce-O-Si bond by XPS.

[0008] Preferably, the preparation method of the hollow titanium dioxide microsphere loaded with a lithium salt-ionic liquid complex includes: the concentration of CTAB is 0.1 M, the hydrothermal temperature is 180 °C, and a complete hollow structure is observed by SEM; the concentration of the LiTFSI solution is 1 M, the impregnation time is 24 h, and the LiTFSI loading is 42% shown by TGA; it is confirmed by zeta potential measurement that the surface charge of the microsphere changes from +35 mV to -28 mV.

[0009] Preferably, the molecular structure of the phosphorus-silicon-boron synergistic flame retardant contains a five-membered ring structure, and the signal of the P-O-B bond at δ = 25 ppm is detected by ³¹P NMR.

[0010] Preferably, the performance parameters of the photocatalytic-photothermal antibacterial agent are as follows: Photothermal conversion efficiency: Under 850 nm laser irradiation, the response time for the surface temperature of the material to rise from 25 °C to 60 °C is ≤ 10 minutes, and the photothermal conversion efficiency reaches 82%; Antibacterial persistence: After 5 cycles of use, the killing rates against Escherichia coli and Staphylococcus aureus are still ≥ 95%, which is better than the 3-cycle lifespan of traditional silver-based antibacterial agents; Structural stability: After heat treatment at 500 °C for 2 hours, observed by transmission electron microscope, The core-shell structure remains intact, without obvious agglomeration or phase change.

[0011] Preferably, the surface modification method of the two-dimensional boron nitride nanosheets is as follows: Treatment with silane coupling agent: Mix BN nanosheets and KH560 silane coupling agent at a mass ratio of 10:1, reflux and react in toluene solution at 100 °C for 3 hours to generate BN-Si-OH nanosheets grafted with -Si-OH groups on the surface; Improvement of interfacial properties: Contact angle measurement shows that the contact angle between the modified BN nanosheets and the silicone matrix decreases from 85° to 40°, and the surface energy increases by 50%; X-ray photoelectron spectroscopy (XPS) detects the characteristic peak of Si-O bond at 1030 to confirm the successful grafting of the coupling agent; Interfacial bonding strength: The interfacial shear strength between BN nanosheets and the matrix measured by single fiber pull-out test increases from 12 MPa to 28 MPa, significantly enhancing the mechanical properties of the composite material.

[0012] Preferably, the compatibility mechanism between the bio-based PLGA and the matrix resin is as follows: Isocyanate chain extension reaction: React PLGA and 4,4'-diphenylmethane diisocyanate at a molar ratio of 10:1 at 80 °C for 2 hours to generate PLGA-urethane-MDI block copolymer. The characteristic peak of urethane bond at 1710 is detected by Fourier transform infrared spectroscopy; Effect of compatibility optimization: The interfacial tension between the chain-extended PLGA and the silicone matrix is reduced by 40%. By scanning electron microscope, the two-phase interface is blurred and there is no obvious phase separation; Dynamic mechanical analysis shows that the width of the glass transition region increases by 25 °C, indicating the formation of an interpenetrating network structure; Improvement of mechanical properties: The elongation at break of the material increases from 80% to 120%, the impact strength increases from 15 kJ / m² to 28 kJ / m², and the tensile strength is maintained at ≥ 45 MPa.

[0013] Preferably, a packaging process for a vehicle energy storage system includes the following steps: Microfluidic mixing: A custom-designed Y-shaped microchannel mixing device with a channel width of 200 μm and a depth of 100 μm is used. By precisely controlling the volume ratio of the dispersed phase to the continuous phase to be 1:5, laminar mixing is achieved under a constant pressure condition of 0.8 MPa. During the mixing process, the residence time of the material in the microchannel is strictly controlled at 20 s. Through DLS technology detection, the average dispersion particle size of the filler after mixing is stably controlled at ≤100 nm, and the standard deviation of the particle size distribution is ≤15 nm, ensuring the nano-level uniformity of the composite material; Magnetic field-induced orientation: The uniformly mixed material is placed in a uniform magnetic field device, and a magnetic field intensity of 0.7 Tesla is applied. The magnetic field direction is perpendicular to the subsequent forming pressure direction; within the orientation time of 10 minutes, the magnetic field induces the magnetic nanoparticles and anisotropic fillers to align along the magnetic field direction through magnetic dipole interaction. X-ray diffraction analysis shows that the full width at half maximum of the graphene crystal plane peak significantly decreases from 2.8° to 1.2°, confirming that the filler forms a highly ordered two-dimensional orientation structure, endowing the material with anisotropic electrical and thermal conductivity properties; Pulse hot pressing forming: A numerical control hydraulic press is used for forming. The set basic pressure is 15 MPa, and a sine wave pulse pressure with an amplitude of 5 MPa and a frequency of 2 Hz is superimposed; at a forming temperature of 135 °C, the material undergoes a dynamic pressure application process for 20 minutes. The periodic change of the pulse pressure promotes the material flow, eliminates internal pores, and improves the density; the density of the finally prepared encapsulation material reaches 1.6 g / cm³, the Shore hardness A90, the tensile strength ≥50 MPa, and the elongation at break ≥100%; Process optimization control: Temperature uniformity: The mold adopts an independent temperature control system, and the temperature fluctuation is controlled within the range of ±2 °C through the PID algorithm, ensuring the consistency of the thermal history of the material during the forming process; Pressure waveform optimization: By simulating the influence of the pulse pressure on the material flow through finite element analysis (FEA), the optimal pulse parameter combination is determined, which improves the uniformity of the internal stress distribution of the material by 30%; Online monitoring: Integrate a pressure sensor and an infrared thermometer to record the pressure-time curve and temperature field distribution during the forming process in real time, and realize the closed-loop control of the process parameters.

[0014] Preferably, the microfluidic mixing unit adopts a spiral microchannel, and the structural parameters are: Geometric design: The spiral radius is 5 mm, the pitch is 1 mm, and the total channel length is 10 cm, forming a progressive spiral flow channel; Flow field optimization: Determine through computational fluid dynamics simulation that the Reynolds number is controlled between 10 - 20 to ensure efficient mixing under laminar flow conditions; Verification of mixing efficiency: The absorbance distribution of the material after mixing is detected by ultraviolet-visible spectroscopy, and the standard deviation ≤0.05, indicating that the dispersion uniformity of the filler reaches the nano-level.

[0015] Preferably, magnetic nanoparticles are added during the magnetic field-induced orientation process: Preparation of nanoparticles: By the coprecipitation method, and are dissolved in deionized water at a molar ratio of 2:1, and ammonia water is added dropwise to pH = 10 at a constant temperature of 80 °C to form black nanoparticles. After magnetic separation, washing, and drying, magnetic particles with a particle size of 20 nm are obtained. Addition ratio: Dispersed in the mixed material at a ratio of 0.3 wt%, and the saturation magnetization intensity measured by a vibrating sample magnetometer is 45 emu / g, ensuring sufficient magnetic dipole moment in the magnetic field.

[0016] (III) Beneficial technical effects Compared with the existing technology, the beneficial effects of the present invention are: 1. The rare earth element-containing organosilicon-carbon nanotube-graphene-MOF hybrid polymer constructs a three-dimensional interpenetrating network structure, with an in-plane thermal conductivity of 12.8 , volume resistivity , and tensile strength > 50 MPa; among them, the coordination bond between Ce³⁺ and Si-OH significantly enhances the interfacial binding energy, and the regular pore structure of MIL-101(Cr) reduces the ion migration activation energy by 35%.

[0017] 2. Intelligent safety protection system: The phosphorus-silicon-boron synergistic flame retardant generates a vitreous composite layer during combustion, increasing the LOI of the material to 34% and achieving a UL94 of V-0 grade; the photocatalytic-photothermal antibacterial agent achieves dual-mode sterilization through a core-shell structure: The photocatalytic sterilization efficiency under visible light is > 99%, and the near-infrared photothermal response raises the surface temperature to 60 °C, with excellent cycle stability.

[0018] 3. Improvement in dynamic environmental adaptability: The intelligent phase change microcapsule-carbon dot composite material increases the phase change enthalpy to 120 J / g and shortens the response time to 15 seconds through the photothermal conversion effect of N-doped carbon dots; the ionic liquid composite loaded in the hollow microspheres has an ionic conductivity stable at

[0019] 4. Green Manufacturing and Long-term Service: The interfacial shear strength of bio-based PLGA modified by MDI chain extension with the silicone matrix is increased by 133%, the impact strength reaches 28 kJ / m², and the natural degradation rate after 180 days is >80%; after the two-dimensional boron nitride nanosheets are modified by KH560, the in-plane thermal conductivity contribution rate is increased to 75%, and at the same time the thermal expansion coefficient of the material is reduced by 40%.

[0020] 5. Precision Manufacturing Process Innovation: The microfluidic mixing technology realizes the uniform dispersion of nano-fillers, the magnetic field-induced orientation makes the alignment degree of anisotropic fillers >85%, the pulse hot pressing forming process improves the material density to 1.6 g / cm³, and shortens the forming cycle by 30% compared with the traditional process; the digital control of the whole process process parameters provides a reliable guarantee for large-scale industrial production. Description of the Drawings

[0021] Figure 1 is the process flow chart of the encapsulation process of the present invention; Figure 2 is the comparative analysis of the dual synergistic effects of thermal management - flame retardancy between the examples and the comparative examples; Figure 3 is the radar analysis chart of the full coverage ability of the thermal multi-functional characteristics between the examples and the comparative examples; Figure 4 is the comparative chart of the multi-dimensional advantages of the thermodynamic strength and durability between the examples and the comparative examples. Detailed Description of the Invention

[0022] Example 1 Raw Material Composition: The following components are used in this example to prepare the encapsulation material for vehicle energy storage systems: Rare earth hybrid polymer: 45 parts, obtained by the silanization treatment of graphene oxide and then compounded with the MIL-101Cr metal-organic framework, and loaded with 5% cerium element; Hollow Microsphere composite: 20 parts, loaded with 42% lithium bis(trifluoromethanesulfonyl)imide and 30% ionic liquid; Phosphorus-silicon-boron flame retardant: 12 parts, with a molar ratio of phosphorus, silicon, and boron of 1.5:1:0.8; Intelligent phase change microcapsule: 8 parts, containing 10% nitrogen-doped carbon dots, with a phase change enthalpy of 120 J / g; Bifunctional ionic liquid plasticizer: 5 parts, prepared by the equimolar reaction of 1-butyl-3-methylimidazolium chloride and lithium bis(trifluoromethanesulfonyl)imide; Photothermal antibacterial agent: 2 parts, Core-shell structure, with a shell thickness of 8 nm; Modified boron nitride nanosheets: 1.5 parts, with the surface grafted with the silane coupling agent KH560; Bio-based PLGA: 4 parts, molar ratio of lactic acid to glycolic acid 75:25, molecular weight 55 kDa; Encapsulation process: Premixing treatment: Put the rare earth hybrid polymer, hollow microsphere composite and flame retardant in a vacuum drying oven, dehydrate at 80 °C for 4 hours to ensure that the moisture content of the raw materials is less than 0.1%; Microfluidic precision mixing: Use a customized Y-shaped microchannel device with a channel width of 200 μm, a depth of 100 μm, and a volume ratio of the dispersed phase to the continuous phase of 1:5. Perform laminar flow mixing under a constant pressure of 0.8 MPa; During the mixing process, the Reynolds number of the fluid is monitored in real time to be 15 - 20 to ensure the laminar flow state; Dynamic light scattering detection shows that the average particle size of the filler after mixing is 80 nm, and the dispersion uniformity index PDI = 0.08; Magnetic field induced orientation: Transfer the mixed material to a uniform magnetic field device, apply a perpendicular magnetic field of 0.7 T for 10 minutes; Detect by a vibrating sample magnetometer, the magnetic moment orientation degree of the magnetic nanoparticles ( , addition amount 0.3 wt%) reaches 85%; X-ray diffraction analysis shows that the full width at half maximum of the graphene crystal plane peak decreases from 2.8° to 1.2°, confirming the highly oriented arrangement of the filler; Pulse hot pressing and forming: Use a numerical control hydraulic press, preheat the mold to 135 °C, the basic pressure is 15 MPa, and a sinusoidal pulse pressure with an amplitude of 5 MPa and a frequency of 2 Hz is superimposed; Monitor the temperature field distribution through an infrared thermal imager during the forming process, and the fluctuation range is ±2 °C; After holding the pressure for 20 minutes, the material density reaches 1.6 g / cm³, Shore hardness A90, and the surface roughness Ra ≤ 0.8 μm; Post-treatment and detection: The formed material is annealed to eliminate internal stress; Detect internal defects through an ultrasonic flaw detector, and the porosity ≤ 0.5%; Example 2 Formulation adjustment: Increase the phosphorus-silicon-boron flame retardant to 15 parts, and adjust the molar ratio of phosphorus, silicon, and boron to 2:1:1; Reduce the photo-thermal antibacterial agent to 1 part, and the other components are the same as in Example 1; Optimization of the encapsulation process: Flame retardant pretreatment: Premix the flame retardant with an ionic liquid plasticizer and stir at 60 °C for 2 hours to enhance the interfacial compatibility; Gradient pressure forming: Use stepped pressure control in the pulse hot pressing stage: The initial pressure of 10 MPa is maintained for 5 minutes, then increased to 18 MPa and held for 10 minutes, and finally reduced to 12 MPa to eliminate residual stress; This process enables the flame retardant to form a continuous network structure in the matrix, and the char residue rate is increased to 25%; Example 3 Process Innovation: Spiral Microfluidic Mixing: Changed the Y-shaped channel to a spiral design with a pitch of 0.5 mm and a total length of 10 cm; Computational fluid dynamics simulation shows that the spiral structure increases the mixing efficiency by 30% and shortens the mixing time to 15 seconds; High-frequency pulsed hot pressing: Increased the pulse frequency to 5 Hz and the forming temperature to 140 °C, and the material density increased to 1.65 g / cm³; Laser flash method testing shows that the phase change response time is shortened from 15 seconds to 10 seconds; Comparative Example Formulation and Process: Matrix Material: 50 parts of ordinary silicone resin, without rare earth modification and MOF composite; Flame Retardant: 25 parts of commercial ammonium polyphosphate; Mixing Process: Twin-screw extruder for melt blending at a temperature of 200 °C and a rotational speed of 200 rpm; Forming Process: Mold pressing with a flat vulcanizer at a pressure of 10 MPa, a temperature of 150 °C, and a pressure holding time of 30 minutes.

[0023] Comparison Table of Thermal and Flame Retardant Properties between Examples and Comparative Examples: Conclusion: Examples 1-3 achieve in-plane thermal conductivity of 12.8 - 13.2 , more than 15 times higher than that of the comparative example. At the same time, the limiting oxygen index reaches 34% - 36%, the combustion residue rate increases by 3 - 5 times, and the smoke density decreases by 60% - 70%, proving the dual breakthroughs of the materials of the present invention in efficient heat dissipation and active fire prevention.

[0024] Comparison Table of Mechanical and Durability Properties between Examples and Comparative Examples: Conclusion: The tensile strength of Examples 1-3 is 52 - 55 MPa, the impact strength is 24 - 28 kJ / m², and the cyclic fatigue life is 450,000 - 550,000 times, which are all superior to those of the comparative example (32 MPa, 8 kJ / m², 100,000 times). The oriented filler arrangement and pulsed hot pressing process reduce the thermal expansion coefficient of the material to , verifying its long-term stability under high-load and wide-temperature conditions.

[0025] Comparison Table of Functional Characteristics between Examples and Comparative Examples: Conclusion: Examples 1-3 all reach the leading level in the industry in five functional indicators: ionic conductivity, photothermal efficiency, antibacterial rate, phase change enthalpy, and environmental degradation rate. Among them, the ionic conductivity of Example 3 , with a photothermal conversion efficiency of 85% and an environmental degradation rate of 82%, which is 30 - 50 times higher than the comparison ratio, demonstrating the advantages of multi-dimensional functional integration and environmental protection, and meeting the complex scenario requirements of vehicle energy storage systems.

[0026] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-performance encapsulation material for a vehicle energy storage system, characterized in that: The encapsulating material is composed of the following components in parts by weight: 30 - 50 parts of a rare earth element-containing silicone-carbon nanotube-graphene-MOF hybrid polymer, and its synthesis reaction is carried out in three steps: The first step is the silylation of graphene oxide: The second step is the in-situ growth of MOF: The third step is the hybrid polymerization: 15 - 25 parts of a hollow titanium dioxide microsphere loaded with a lithium salt-ionic liquid composite, and the preparation process: Preparation of microspheres by the template method: Loading of lithium salt: Anchoring of ionic liquid: 10 - 15 parts of a phosphorus-silicon-boron synergistic flame retardant, and the synthesis reaction formula is: Phosphorus:Silicon:Boron molar ratio 1.5:1:0.8, forming a glassy state when burning Composite protective layer, limiting oxygen index reaching 34%; 5 - 10 parts of an intelligent phase change microcapsule-carbon dot composite. Glucose and ethylenediamine are reacted in an autoclave at 180 °C for 2 h to obtain N-doped carbon dots with a particle size of 3 - 5 nm; the carbon dots are embedded in a polyurea-polyurethane wall material at a ratio of 10 wt%, and the phase change enthalpy of this composite reaches 120 J / g, and the response time ≤ 15 s; 3 - 8 parts of a bifunctional ionic liquid plasticizer. 1-Butyl-3-methylimidazolium chloride and lithium bis(trifluoromethanesulfonyl)imide are reacted in an acetone solvent at an equimolar ratio at 60 °C for 8 hours to generate the target ionic liquid; 1-3 parts of photocatalytic-photothermal antibacterial agent, and the nano- particles are dispersed in silver nitrate solution, irradiated with ultraviolet light and reduced with sodium borohydride to form a core layer of Ag nanoparticles with a particle size of 5-10 nm; Then, a copper sulfide layer is deposited on the surface by the aqueous precipitation method, and the reaction conditions are controlled to precisely regulate the thickness of the CuS layer to 8 nm; 0.5 - 2 parts of two-dimensional boron nitride nanosheets. Bulk boron nitride and N,N-dimethylformamide are mixed at a mass ratio of 1:10 and treated under an ultrasonic power of 200 W for 4 h to obtain BN nanosheets with a thickness of 6 - 12 nm and a lateral size of 2 - 5 μm; 3 - 5 parts of bio-based PLGA, which is synthesized by ring-opening polymerization. Lactic acid LA and glycolic acid GA are mixed at a molar ratio of 75:25, 0.8 wt% of stannous octoate is added as a catalyst, and the reaction is carried out at 140 °C under nitrogen protection for 24 h to generate a random copolymer with a weight-average molecular weight of 55 kDa.

2. The high-performance encapsulation material for a vehicle energy storage system according to claim 1, characterized in that: The synthesis process of the rare earth element-containing organosilicon-carbon nanotube-graphene-MOF hybrid polymer includes: GO and KH570 are refluxed in toluene at a mass ratio of 1:3, and the characteristic peak of the Si-O-C bond at 1100 is detected by FTIR; solvent thermal method is used to grow MIL-101(Cr) on the surface of GO, and the characteristic peaks of MOF appear at 2θ = 9.5° and 19.0° in the XRD pattern; microwave-assisted coordination reaction between Ce³⁺ and Si-OH is promoted, and the formation of the Ce-O-Si bond is confirmed by XPS.

3. The high-performance encapsulation material for a vehicle energy storage system according to claim 1, characterized in that: The preparation method of the hollow titanium dioxide microsphere loaded with the lithium salt-ionic liquid composite includes: the CTAB concentration is 0.1 M, the hydrothermal temperature is 180 °C, and a complete hollow structure is observed by SEM; the LiTFSI solution concentration is 1 M, the impregnation time is 24 h, and the TGA shows that the LiTFSI loading amount is 42%; the surface charge of the microspheres is confirmed to change from +35 mV to -28 mV by zeta potential measurement.

4. The high-performance encapsulation material for a vehicle energy storage system according to claim 1, characterized in that: The molecular structure of the phosphorus-silicon-boron synergistic flame retardant contains a five-membered ring structure, and the P-O-B bond signal at δ = 25 ppm is detected by ³¹P NMR.

5. The high-performance encapsulation material for a vehicle energy storage system according to claim 1, characterized in that: The photocatalytic-photothermal antibacterial agent enables the material to have a response time of ≤ 10 minutes for the surface temperature to rise from 25 °C to 60 °C under 850 nm laser irradiation with a power density of 1 W / cm², a photothermal conversion efficiency of 82%, and after 5 cycles of use, the killing rates against Escherichia coli and Staphylococcus aureus are still ≥ 95%. After heat treatment at 500 °C for 2 hours, observed by transmission electron microscope, the core-shell structure remains intact.

6. The high-performance encapsulation material for a vehicle energy storage system according to claim 1, characterized in that: The surface modification method of the two-dimensional boron nitride nanosheets is: BN nanosheets and KH560 silane coupling agent are mixed at a mass ratio of 10:1 and refluxed in a toluene solution at 100 °C for 3 hours to generate BN-Si-OH nanosheets with surface-grafted -Si-OH groups; the interfacial shear strength between the BN nanosheets and the matrix is measured to increase from 12 MPa to 28 MPa by the single fiber pull-out test.

7. The high-performance encapsulation material for a vehicle energy storage system according to claim 1, characterized in that: The compatibility mechanism between the bio-based PLGA and the matrix resin is as follows: PLGA and 4,4'-diphenylmethane diisocyanate are reacted at a molar ratio of 10:1 at 80 °C for 2 hours to generate a PLGA-urethane-MDI block copolymer. After chain extension, the interfacial tension between the PLGA and the silicone matrix is reduced by 40%; dynamic mechanical analysis shows that the width of the glass transition region increases by 25 °C; the elongation at break of the material increases from 80% to 120%, and the impact strength increases from 15 kJ / m² to 28 kJ / m², while maintaining a tensile strength ≥ 45 MPa.

8. The encapsulation process of a high-performance encapsulation material for a vehicle energy storage system according to any one of claims 1-7, characterized in that: It includes the following steps: Microfluidic mixing: A custom-designed Y-shaped microchannel mixing device with a channel width of 200 μm and a depth of 100 μm is used. By precisely controlling the volume ratio of the dispersed phase to the continuous phase to be 1:5, laminar flow mixing is achieved under a constant pressure condition of 0.8 MPa. During the mixing process, the residence time of the material in the microchannel is strictly controlled to be 20 s. Through DLS technology detection, the average dispersed particle size of the filler after mixing is stably controlled at ≤ 100 nm, and the standard deviation of the particle size distribution is ≤ 15 nm. Magnetic field-induced orientation: The uniformly mixed material is placed in a uniform magnetic field device, and a magnetic field intensity of 0.7 T is applied. The magnetic field direction is perpendicular to the subsequent molding pressure direction. During the 10 min orientation time, the magnetic field induces the magnetic nanoparticles and anisotropic fillers to align along the magnetic field direction through magnetic dipole interaction. X-ray diffraction (XRD) analysis shows that the full width at half maximum of the graphene (002) crystal plane peak decreases significantly from 2.8° to 1.2°. Pulse hot pressing molding: A numerical control hydraulic press is used for molding. The base pressure is set to 15 MPa, and a sine wave pulse pressure with an amplitude of 5 MPa and a frequency of 2 Hz is superimposed. At a molding temperature of 135 °C, the material undergoes a 20 min dynamic pressure application process. The finally obtained encapsulation material has a density of 1.6 g / cm³, a Shore hardness A90, a tensile strength ≥ 50 MPa, and an elongation at break ≥ 100%. Process optimization control: The mold adopts an independent temperature control system, and the temperature fluctuation is controlled within ±2 °C through the PID algorithm; the influence of the pulse pressure on the material flow is simulated through finite element analysis to determine the optimal pulse parameter combination; a pressure sensor and an infrared thermometer are integrated to record the pressure-time curve and the temperature field distribution during the molding process in real time.

9. The encapsulation process of a high-performance encapsulation material for a vehicle energy storage system according to claim 8, characterized in that: The microfluidic mixing unit adopts a spiral microchannel with a spiral radius of 5 mm, a pitch of 1 mm, and a total channel length of 10 cm; the Reynolds number is controlled between 10 - 20 through computational fluid dynamics simulation to ensure efficient mixing under laminar flow conditions; the absorbance distribution of the material after mixing is detected by ultraviolet-visible spectroscopy, and the standard deviation is ≤ 0.

05.

10. The encapsulation process of a high-performance encapsulation material for a vehicle energy storage system according to claim 8, characterized in that: Magnetic nanoparticles are added during the magnetic field-induced orientation process and dispersed in the mixed material at a ratio of 0.3 wt%. The saturation magnetization measured by a vibrating sample magnetometer is 45 emu / g. The magnetic nanoparticles are prepared by dissolving and in deionized water at a molar ratio of 2:1, adding ammonia water dropwise to pH = 10 under the condition of constant temperature at 80 °C to generate black nanoparticles, and then obtaining them through magnetic separation, washing, and drying.

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