Rapidly-formed thermal-runaway-preventing material

Abstract

Disclosed in the present invention is a rapidly-formed thermal-runaway-preventing material. The thermal-runaway-preventing material comprises the following components in percentages by mass: 71-95% of a heat-absorbing material, 1.5-12% of polyvinyl alcohol, 0-1% of a long-chain alkyl diacid and 3-16% of a UV curing packaging resin. The thermal-runaway-preventing material can be designed according to different battery structures, such that a piece of the thermal-runaway-preventing material can be conveniently placed between battery packs, or can be placed every certain number of battery packs. The thermal-runaway-preventing material of the present invention has a high enthalpy value of heat absorption, can generate a chemical reaction between 90-400°C and actively absorb heat. Generally, the temperature is rapidly increased after thermal runaway of a battery pack, such that the temperature of the thermal-runaway-preventing material reaches 90ºC or above, and the material can spontaneously absorb heat and be decomposed at this moment, thereby forming a continuous heat absorption effect (the enthalpy of heat absorption of the heat absorption material ＞ 1200 J / g), so as to lower the temperature of the runaway battery pack. In addition, after the preventing material is completely decomposed, a porous structure can be formed on the surface, and the material becomes a superior thermal insulation material, thereby preventing heat from being transferred to adjacent batteries, preventing the adjacent batteries from being continuously heated, and avoiding fire and explosion.

Description

A rapid prototyping thermal runaway protection material Technical Field

[0001] The present invention belongs to the technical field of thermal runaway protection materials, and in particular relates to a rapid prototyping thermal runaway protection material. Background Art

[0002] As a high-energy-density storage solution, lithium-ion batteries have been widely adopted in portable energy storage devices and electric vehicles, and are considered the most competitive power source for future green smart grid energy storage. However, high energy density also carries significant safety risks. Components such as the electrolyte and separator in existing lithium-ion batteries are flammable and explosive. Furthermore, during operation, uneven internal component distribution and contact, as well as external thermal, mechanical, and electrical abuse, can trigger internal short circuits, releasing significant heat, leading to rapid temperature increases and thermal runaway. This can cause the release of toxic gases and smoke, fires, and even explosions, posing significant risks. In large-scale energy storage systems, thermal runaway of a single cell can trigger a chain reaction in neighboring cells, ultimately resulting in a disaster. According to incomplete statistics, over 60 safety incidents have occurred in battery energy storage power plants worldwide over the past decade, as well as numerous electric vehicle fires. Due to the continued rise in raw material costs for lithium-ion batteries, sodium-ion batteries, as a new generation of power batteries with lower theoretical costs, have become a research hotspot. However, sodium-ion batteries also suffer from thermal runaway. This has made improving the safety of lithium / sodium batteries a key topic in battery research.

[0003] The existing thermal management solutions are mainly as follows: (1) Using aerogel to separate each battery pack component. After a single battery pack thermal runaway, the heat can be isolated within a limited range under non-serious conditions. However, aerogel cannot slow down the process of thermal runaway. When thermal runaway occurs, there is still a possibility of spillover to adjacent battery packs, causing continuous thermal runaway and fire or explosion. (2) Using phase change materials to manage battery thermal management. Usually, the phase change enthalpy of phase change materials is only between 200 and 270 J / g, and after packaging, it is usually only between 100 and 200 J / g. Due to the low enthalpy, phase change materials are usually used to maintain a constant operating temperature (such as 55°C) for the battery to maximize its performance, but cannot solve the problem of thermal runaway. (3) Installing a liquid cooling system on the battery and using a compressor for refrigeration to cool the battery. Due to the power limitation and feedback delay limitation of the compressor, the cooling efficiency of the liquid cooling system is limited and cannot cope with the instantaneous temperature rise.

[0004] Typically, thermal runaway in a battery pack occurs when a single battery cell experiences thermal runaway, then expands and generates significant heat. This heat then spreads to adjacent battery packs, causing thermal runaway in those packs and ultimately spreading to the entire pack, leading to fire and explosion. Therefore, if a material could be used to isolate the thermally runaway battery cell and absorb and cool it, preventing the spread of thermal runaway to adjacent packs, fire and explosion could be effectively suppressed.

[0005] Summary of the Invention

[0006] In order to address the deficiencies of the prior art, the main purpose of the present invention is to provide a rapid-forming thermal runaway protection material, which can be designed according to different battery structures, so that it can be placed between battery packs, or one piece can be placed every certain number of battery packs. The thermal runaway protection material of the present invention has a high endothermic enthalpy, and will undergo a chemical reaction and actively absorb heat between 90-400°C. Usually, after a thermal runaway, the battery pack will heat up rapidly, causing the thermal runaway protection material to reach above 90°C. At this time, the material will spontaneously endothermically decompose. Because the material has a high enthalpy value, it forms a continuous endothermic effect (the endothermic enthalpy of the endothermic material is greater than 1200 J / g), which drives the temperature of the runaway battery pack to drop. Moreover, after the decomposition of the protective material is complete, a porous structure will be formed, which becomes an excellent thermal insulation material, preventing heat from being transferred to adjacent batteries, preventing adjacent batteries from continuing to heat up, and avoiding fire and explosion.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A rapid-prototyping thermal runaway protection material comprises the following components by mass percentage: 71-95% of a heat-absorbing material, 1.5-12% of polyvinyl alcohol, 0-1% of a long-chain alkyl diacid, and 3-16% of a UV-curing encapsulating resin.

[0009] In the above technical solution, the heat-absorbing material includes one or more of sodium acetate trihydrate, ammonium ferric oxalate trihydrate, citric acid monohydrate, citric acid, oxalic acid dihydrate, anhydrous oxalic acid, malonic acid, magnesium sulfate heptahydrate, zinc sulfate heptahydrate, succinic acid, maleic acid, fumaric acid, sodium carbonate decahydrate, calcium chloride hexahydrate, aluminum nitrate nonahydrate, ammonium pentaborate octahydrate, ammonium ferric sulfate dodecahydrate, ferrous chloride tetrahydrate, ammonium oxalate monohydrate, sodium tetraborate decahydrate, sodium tetraborate pentahydrate, aluminum sulfate 18hydrate, ammonium pentaborate, ammonium hydrogen borate tetrahydrate, boric acid, barium hydroxide octahydrate, sodium silicate pentahydrate, silicic acid, hydrated silicic acid, ammonium aluminum sulfate dodecahydrate, hydrated sodium aluminum silicate, potassium aluminum sulfate dodecahydrate, sodium sulfate decahydrate, copper sulfate heptahydrate, ferrous sulfate heptahydrate, cobalt chloride hexahydrate, and calcium sulfate dihydrate, and the mesh size is preferably 80-300 mesh.

[0010] Preferably, the heat-absorbing material includes one or more of oxalic acid dihydrate, anhydrous oxalic acid, ammonium oxalate monohydrate, sodium acetate trihydrate, boric acid, ammonium pentaborate octahydrate, barium hydroxide octahydrate, sodium tetraborate decahydrate, potassium aluminum sulfate dodecahydrate, sodium sulfate decahydrate, calcium sulfate dihydrate, etc., and the preferred mesh size is 80-300 mesh.

[0011] In the above technical solution, the UV curing encapsulation resin includes the following components in percentage by mass: 25-70% of silicone-epoxy resin composite modified polyurethane acrylate, 0-5% of epoxy resin, 5-40% of epoxy acrylate, 0-5% of acrylic acid, 5-30% of active monomer, 0-1% of long-chain alkyl diacid, 0-25% of silane modified resin, 0.1-3% of water scavenger, 0-10% of spherical silica powder, 0.1-3% of photoinitiator, and 0.01-0.3% of polymerization inhibitor.

[0012] Specifically, the preparation method of the UV curable encapsulation resin is as follows: the components are added into a reactor according to a proportion, stirred at 50-60° C. for 2-3 hours, and finally a dehydrating agent is added and stirred for 10-30 minutes to obtain the UV curable encapsulation resin.

[0013] Specifically, the epoxy resin refers to a substance containing an epoxy bond in its molecular structure, including one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, bisphenol S epoxy resin, epoxy soybean oil, cardanol-modified epoxy resin, trimethylolpropane triglycidyl ether, hexanediol diglycidyl ether, and phenyl glycidyl ether.

[0014] Specifically, the epoxy acrylate is a product obtained by ring-opening a mixture of acrylic acid and carboxyethyl acrylate in any proportion with the above-mentioned epoxy resin, including CN104NS or CN120NS from Sartomer.

[0015] Specifically, the active monomer is an acrylate monomer with 1-6 functions that does not contain a hydroxyl structure, including one or more of isobornyl acrylate, 2-cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, isobornyl methacrylate, and tetrahydrofurfuryl methacrylate.

[0016] Specifically, the long-chain alkyl diacid includes one or more of dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosanedioic acid; and the long-chain alkyl diacid has a good dispersing effect on silicon powder.

[0017] Specifically, the silane-modified resin is a resin having an alkoxysilyl group at the end group, including one or more of silane-modified polyether resin, silane-modified polyacrylate resin, silane-modified polyurethane resin, silane-modified polyester resin, and alkoxy silicone resin, and the alkoxysilane group includes one or more of trimethoxysilane, triethoxysilane, methyldimethoxysilane, and methyldiethoxysilane.

[0018] Specifically, the dehydrating agent is toluenesulfonyl isocyanate, which can effectively remove residual moisture in the system, prevent hydrolysis of siloxane on the siloxane-epoxy resin composite modified polyurethane acrylate and silane modified resin structure, and improve the storage stability of UV curing encapsulation resin.

[0019] Specifically, the spherical silicon micropowder has a D50 of 50-300 μm and a D100 of less than 500 μm. Large particles of the spherical silicon micropowder can conduct ultraviolet light from outside to deep layers.

[0020] More specifically, when preparing a thermal runaway protection material having a thickness greater than 5 mm, spherical silicon powder is preferably added.

[0021] Specifically, the photoinitiator is a substance that can decompose or abstract hydrogen to generate free radicals under ultraviolet light, including 4-benzoyl-4'-methyl-diphenyl sulfide (BMS), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), 2,4,6-trimethylbenzoylphosphonic acid ethyl ester (TPO-L), bis(2,4,6-trimethylbenzyl)phenylphosphine oxide (819), benzoin dimethyl ether (651), 2-methyl-1-(4-methylmercaptophenyl)-2-morpholino-1-propane One or more of the following: ketone (907), polymerized [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide (TMO), 1-(9,9-dibutyl-9H-fluoren-2-yl)-2-methyl-2-morpholin-4-yl-propane-1-one, 1-hydroxycyclohexyl benzophenone (184), 4-acryloyloxybenzophenone, and methyl o-benzoylbenzoate (OMBB); under the irradiation of ultraviolet light, the surface of the thermal runaway protection material will quickly solidify and form a material with a certain strength, which is conducive to subsequent transportation.

[0022] Specifically, the polymerization inhibitor is p-hydroxyanisole, which is used to prevent the semi-adduct generated by the reaction of diisocyanate and hydroxy acrylate from polymerizing prematurely in the subsequent process.

[0023] Specifically, the polyvinyl alcohol is in the form of a powder, preferably with a mesh size of 80-300. Polyvinyl alcohol contains a large number of hydroxyl groups in its structure, which has good water absorption. A small amount of water is adsorbed on the powder surface. This water reacts with the siloxane structure in the UV encapsulation resin to form a silanol structure, which then undergoes a condensation reaction with the hydroxyl groups or crystal water on the surface of the heat-absorbing material, thereby enhancing the interfacial bonding between the encapsulation resin and the heat-absorbing material.

[0024] Specifically, the preparation method of the silicone-epoxy resin composite modified polyurethane acrylate comprises the following steps:

[0025] S1: Add diisocyanate and hydroxy acrylate in a molar ratio of 1:1 to reactor A, add 0.01-0.2% of the total mass of the diisocyanate and hydroxy acrylate as a catalyst dibutyltin dilaurate, and 0.01-0.2% of the total mass of the diisocyanate and hydroxy acrylate as a polymerization inhibitor p-hydroxyanisole, raise the temperature to 40-60°C, react for 1-3 hours, and obtain a semi-adduct of diisocyanate and hydroxyethyl acrylate, and calculate the theoretical NCO equivalent.

[0026] S2: Add epoxy resin and mercaptosilane coupling agent into reactor B in a molar ratio of epoxy bond to mercapto group of 1:1, add catalyst triethylamine at a concentration of 0.01-0.2% of the total mass of epoxy resin and mercaptosilane coupling agent, raise the temperature to 70-90°C and react for 1-3 hours to obtain siloxane-modified epoxy resin, and calculate the theoretical hydroxyl equivalent.

[0027] S3: According to the calculation method of NCO equivalent: hydroxyl equivalent = mass of semi-adduct: mass of siloxane-modified epoxy resin, a set amount of siloxane-modified epoxy resin is added to reactor A, and 0.01-0.2% of the total mass of the siloxane-modified epoxy resin is added as a catalyst dibutyltin dilaurate and 0.01-0.2% of the total mass of the siloxane-modified epoxy resin as a polymerization inhibitor p-hydroxyanisole. The reaction is stirred at 60-80°C for 2-8 hours, and the infrared spectrometer is used to detect the wavelength at 2260 cm -1 After the isocyanate absorption peaks of about 500 nm disappear, the silicone-epoxy resin modified polyurethane acrylate is obtained.

[0028] Wherein, in step S1, the diisocyanate includes one or more of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), toluene diisocyanate (T100 / T80 / T65), xylene diisocyanate (XDI), trimethylol diisocyanate (TMDI), 1,5-naphthalene diisocyanate (NDI), and diphenylmethane diisocyanate (MDI-100 / MDI-50).

[0029] Wherein, in step S1, the hydroxy acrylate includes one or more of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, and 4-hydroxybutyl acrylate.

[0030] Among them, in step S1, the epoxy resin refers to a substance containing an epoxy bond in its molecular structure, including one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, bisphenol S epoxy resin, epoxy soybean oil, cardanol-modified epoxy resin, trimethylolpropane triglycidyl ether, hexanediol diglycidyl ether, and phenyl glycidyl ether.

[0031] Wherein, in step S2, the mercaptosilane coupling agent includes one or more of mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptopropylmethyldimethoxysilane, and mercaptopropylmethyldiethoxysilane.

[0032] Wherein, in step S1, 0-30% of the total mass of diisocyanate and hydroxy acrylate is added to the acrylate monomer; in step S2, 0-30% of the total mass of epoxy resin and mercaptosilane coupling agent is added to the acrylate monomer;

[0033] or

[0034] In step S1, 0-30% of the total mass of diisocyanate and hydroxy acrylate is added as an acrylate monomer; in step S3, 0-30% of the total mass of siloxane-modified epoxy resin is added as an acrylate monomer;

[0035] or

[0036] In step S2, 0-30% of the total mass of the epoxy resin and the mercaptosilane coupling agent is added to the acrylate monomer; in step S3, 0-30% of the total mass of the siloxane-modified epoxy resin is added to the acrylate monomer;

[0037] or

[0038] In step S1, 0-30% of the total mass of diisocyanate and hydroxy acrylate is added as acrylate monomer; in step S2, 0-30% of the total mass of epoxy resin and mercaptosilane coupling agent is added as acrylate monomer; in step S3, 0-30% of the total mass of siloxane-modified epoxy resin is added as acrylate monomer.

[0039] Wherein, in step S1, 0-30% of the total mass of diisocyanate and hydroxy acrylate is added into an acrylate monomer; or

[0040] In step S2, adding 0-30% of the total mass of the epoxy resin and the mercaptosilane coupling agent to an acrylate monomer; or

[0041] In step S3, 0-30% of the total mass of the silicone-modified epoxy resin is added as an acrylate monomer;

[0042] Specifically, the acrylate monomer is an acrylate monomer with 1-6 functions that does not contain a hydroxyl structure, including one or more of isobornyl acrylate, 2-cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, isobornyl methacrylate, and tetrahydrofurfuryl methacrylate.

[0043] In the above technical solution, the preparation method of the thermal runaway protection material is as follows:

[0044] All components are added into a mixing kettle, mixed evenly, and then pressurized and formed in a mold, and then cured by ultraviolet light to obtain a thermal runaway protection material.

[0045] In the above technical solution, the ultraviolet lamp is a high-pressure mercury lamp or a metal halide lamp.

[0046] Specifically, the UV lamp is a UV lamp in the 365nm-405nm band, including a composite UV lamp composed of one or more UV LED lamps in the 365nm band, 385nm band, 395nm band, and 405nm band. The UV lamp is installed in a single-sided manner, aligned with the top and bottom, or staggered. The irradiation power received by the surface of the thermal runaway protection material is greater than 30mW / cm 2 , irradiation dose>1J / cm 2 .

[0047] In the above technical solution, the thermal runaway protection material is cut according to the structure of the battery pack and packaged in a sealed and pressure-resistant shell; according to the application scenario of the energy storage battery, it is packaged with independent thermal runaway protection material, or packaged after being laminated with thermal insulation buffer material to increase the compression ratio of the thermal protection material and buffer the expansion and extrusion of the battery.

[0048] In the above technical solution, the thermal runaway protection material is used alone as a thermal runaway protection material, or is used in combination with an insulation material or a physical insulation structure to form a thermal protection system, and the thermal runaway protection material serves as a heat-absorbing material in the thermal protection system.

[0049] The thermal runaway protection material of the present invention is used for thermal runaway protection of various batteries, preferably lithium-ion batteries and sodium-ion batteries.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1. The thermal runaway protection material of the present invention uses photocuring rapid prototyping to shape the pressed high-density material, and can be designed according to different battery structures to meet the needs of different scenarios.

[0052] 2. When a battery experiences thermal runaway, the thermal runaway protection material of the present invention can prevent the spread of thermal runaway and reduce the impact on adjacent batteries.

[0053] 3. Since most endothermic materials are powders or block crystals, prolonged exposure to air can lead to volatilization of crystal water and changes in volume and shape due to moisture absorption in high humidity. These materials do not conform to the required shape and size of battery packs and cannot be used directly. The thermal runaway protection material described in this invention is an organic-inorganic composite material. A UV-curable encapsulating resin is coated on the surface of the endothermic material, achieving stable encapsulation of the endothermic material. Furthermore, after UV irradiation, the spherical silica powder within the adhesive resin guides the UV light deep into the surface, achieving dual curing, which allows for the one-time curing of a 40mm thick thermal runaway protection material.

[0054] 4. The thermal runaway protection material of the present invention has a high endothermic enthalpy (the endothermic enthalpy of the endothermic material is greater than 1200 J / g). A chemical reaction will occur between 90-400°C and the material will actively absorb heat. When the temperature reaches above 90°C, the material will spontaneously endothermically decompose, forming a continuous endothermic effect, driving the temperature of the runaway battery pack to drop. Moreover, after the decomposition of the protective material is completed, a porous structure will be formed on the surface of the material, making it an excellent thermal insulation material, preventing heat from being transferred to adjacent batteries, preventing adjacent batteries from continuing to heat up, and avoiding fire and explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The present invention will be further described below in conjunction with the accompanying drawings:

[0056] FIG1 is a schematic diagram of the curing process of the thermal runaway protection material of the present invention;

[0057] In the figure, heat absorbing material 1, spherical silicon powder 2, polyvinyl alcohol 3, light transmitting spherical silicon powder 4, UV curing encapsulating resin (before curing) 5, UV curing encapsulating resin (after curing) 6;

[0058] FIG2 is a schematic diagram of the endothermic decomposition process of the thermal runaway protection material of the present invention;

[0059] In the figure, endothermic material 1, endothermic material decomposition residue 2, polyvinyl alcohol 3, UV curable encapsulation resin (after curing) 4, spherical silicon powder 5, pores formed after decomposition of the endothermic material 6;

[0060] FIG3 is a schematic diagram of the test device of the present invention. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0062] Figure 1 shows the curing process of the thermal runaway protection material of the present invention. The surface of the thermal runaway protection material is coated with a UV curing encapsulation resin. After being irradiated with ultraviolet light, the spherical silicon powder inside the adhesive resin guides the ultraviolet light into the deep layer, achieving one-time curing and molding.

[0063] Figure 2 is an endothermic decomposition diagram of the thermal runaway protection material of the present invention. The endothermic enthalpy of the thermal runaway protection material is high (the endothermic enthalpy of the endothermic material is greater than 1200 J / g). After the thermal runaway, the battery pack heats up rapidly, causing the thermal runaway protection material to reach above 90°C. At this time, the material will spontaneously endothermically decompose, forming a continuous endothermic effect, driving the temperature of the runaway battery pack to drop. After the decomposition of the protective material is completed, a porous structure will be formed on the surface of the material, becoming an excellent thermal insulation material to prevent heat transfer and avoid fire and explosion of the battery pack.

[0064] Some of the special raw materials used in the following examples are shown in Table 1.

[0065] Table 1

[0066] The siloxane-epoxy resin composite modified polyurethane acrylate and silane-modified resin used in the present invention are specifically prepared by the following method:

[0067] 1. Preparation of siloxane-epoxy resin composite modified polyurethane acrylate:

[0068] S1: 444.58 g (2 mol) of isophorone diisocyanate, 236.98 g (2 mol, 98% purity) of 2-hydroxyethyl acrylate, 0.4 g of a catalyst (dibutyltin dilaurate), and 0.5 g of a polymerization inhibitor (p-hydroxyanisole) were added to reactor A, and the temperature was raised to 40-45° C. for reaction for 3 hours to obtain a semi-adduct of diisocyanate and hydroxyethyl acrylate, with a calculated theoretical NCO equivalent weight of 341.23 g / mol;

[0069] S2: Add 510 g (1.5 mol of bisphenol F epoxy resin, 3 mol of epoxy bonds) of bisphenol F epoxy resin, 841.11 g (3 mol) of mercaptopropyltriethoxysilane, and 1.35 g of catalyst (triethylamine) to reactor B, raise the temperature to 85° C., and react for 2.5 hours to obtain a siloxane-modified epoxy resin for later use. The calculated theoretical hydroxyl equivalent weight is 450.82 g / mol.

[0070] S3: According to the calculation method of NCO equivalent: hydroxyl equivalent = mass of semi-adduct: mass of siloxane-modified epoxy resin, there are 682.46g of semi-adduct in reactor A. 901.64g of siloxane-modified epoxy resin is added to reactor A, 180g of 1,6-hexanediol diacrylate, 0.7g of catalyst (dibutyltin dilaurate), and 0.9g of inhibitor (p-hydroxyanisole) are added, and the reaction is stirred at 70-75℃ for 4h. The infrared spectrometer is used to detect the concentration of 2260cm -1 After the isocyanate absorption peaks around 100 nm disappear, the siloxane-epoxy resin composite modified polyurethane acrylate Si / EP-PUA-1 is obtained.

[0071] 2. Preparation of silane-modified resin G-PUA-1:

[0072] 560.74 g of mercaptopropyl triethoxysilane and 222.29 g of isophorone diisocyanate were added to a reactor, and 0.7 g of dibutyltin dilaurate was added. The reaction was maintained at 85° C. for 4.5 hours to obtain the silane-modified resin G-PUA-1.

[0073] 3. Preparation of silane-modified resin G-PUA-2:

[0074] 392.68 g of mercaptopropyltrimethoxysilane and 222.29 g of isophorone diisocyanate were added to a reactor, and 0.53 g of dibutyltin dilaurate was added. The reaction was maintained at 85° C. for 4.5 hours to obtain the silane-modified resin G-PUA-2.

[0075] Example 1:

[0076] A rapid prototyping thermal runaway protection material comprises the following components, calculated by mass percentage: 30% citric acid, 52% magnesium chloride hexahydrate, 7.9% polyvinyl alcohol, 0.1% eicosanedioic acid, and 10% UV-curable encapsulating resin UV-1. The preparation method is as follows:

[0077] S1: Add 300g citric acid, 520g magnesium chloride hexahydrate, 79g polyvinyl alcohol, 1g eicosanedioic acid, and 100g UV curable encapsulation resin UV-1 into a mixing kettle and mix well;

[0078] S2: Pour the mixture into a 227 mm × 160 mm × 2 mm mold and use the mold to press the mold under a hydraulic press with a feed mass of 110 g and a pressure of 10.6 MPa;

[0079] S3: After the pressed material is demoulded, place it under 100mW / cm 2 The irradiation dose was 4J / cm2 for 40s under a metal halide lamp. 2After CNC (numerical control machine) grinding, the thermal protection material RF-A2 with a smooth surface is obtained.

[0080] The UV curable encapsulation resin UV-1 comprises the following components by mass percentage: 1.2% of siloxane-epoxy resin composite modified polyurethane acrylate Si / EP-PUA-14, 1% of bisphenol A epoxy resin, 33% of epoxy acrylate, 9% of active monomer (trimethylolpropane triacrylate), 5% of active monomer (dipropylene glycol diacrylate), 0.2% of hexadecanedioic acid, 2% of silane modified resin GPUA-1, 0.5% of p-toluenesulfonyl isocyanate, 5% of spherical silica powder, 1% of photoinitiator (184), 1% of 4-acryloyloxybenzophenone, 1% of photoinitiator (TPO), and 0.1% of polymerization inhibitor (p-hydroxyanisole). The preparation method thereof is as follows:

[0081] 412 g of siloxane-epoxy resin composite modified polyurethane acrylate Si / EP-PUA-1, 10 g of bisphenol A epoxy resin, 330 g of epoxy acrylate (CN120NS), 10 g of acrylic acid, 90 g of active monomer (trimethylolpropane triacrylate), 50 g of active monomer (tripropylene glycol diacrylate), 2 g of hexadecanedioic acid, 20 g of silane-modified resin (GPUA-1), 5 g of p-toluenesulfonyl isocyanate, 50 g of spherical silica powder, 10 g of photoinitiator (184), 10 g of 4-acryloyloxybenzophenone, 10 g of photoinitiator (TPO), and 1 g of inhibitor (p-hydroxyanisole) were added into a reactor, maintained at 55° C. and stirred for 2.5 hours, 5 g of p-toluenesulfonyl isocyanate was added, and stirred for 20 minutes to obtain a UV-curable encapsulation resin UV-1.

[0082] The thermal conductivity, enthalpy, density, average thickness and compressive strength of the thermal runaway protection material RF-A2 prepared in this example are shown in Table 2.

[0083] Example 2:

[0084] A rapid prototyping thermal runaway protection material comprises the following components, calculated by mass percentage: 85% potassium aluminum sulfate dodecahydrate, 6.5% polyvinyl alcohol, 0.5% hexadecanedioic acid, and 8% UV-curable encapsulating resin. The preparation method is as follows:

[0085] S1: Add 850g of potassium aluminum sulfate dodecahydrate, 65g of polyvinyl alcohol, 5g of hexadecanedioic acid, and 80g of UV curable encapsulation resin UV-1 into a mixing kettle and mix well;

[0086] S2: The mixture was poured into a 227 mm × 160 mm × 5 mm mold with a polytetrafluoroethylene coating and pressed into shape using a hydraulic press. The mass of the material was 292.5 g and the pressure was 8.7 MPa.

[0087] S3: After the pressed material is demoulded, place it under 100mW / cm 2 The irradiation dose was 4J / cm2 for 40s under a metal halide lamp. 2 After CNC (numerical control machine) grinding, the thermal runaway protection material RF-B5 with a smooth surface is obtained.

[0088] The UV curing encapsulation resin UV-1 and its preparation method are the same as those in Example 1.

[0089] The thermal conductivity, enthalpy, density, average thickness and compressive strength of the thermal runaway protection material RF-B5 prepared in this example are shown in Table 2.

[0090] Example 3:

[0091] A rapid prototyping thermal runaway protection material comprises the following components, calculated by mass percentage: 30% citric acid, 54% magnesium chloride hexahydrate, 8% polyvinyl alcohol, and 8% UV-curable encapsulating resin UV-28%. The preparation method is as follows:

[0092] S1: Add 600g of citric acid, 1080g of magnesium chloride hexahydrate, 160g of polyvinyl alcohol, and 160g of UV curable encapsulation resin UV-2 into a mixing kettle and mix well;

[0093] S2: The mixture was poured into a 227 mm × 160 mm × 15 mm mold and pressed using a hydraulic press with a mass of 817.5 g and a pressure of 12.0 MPa.

[0094] S3: After the pressed material is demoulded, place it under 100mW / cm 2 The irradiation was carried out under a metal halide lamp for 60 seconds, and the irradiation dose was 6J / cm 2 After CNC (numerical control machine) grinding, the thermal runaway protection material RF-C15 with a smooth surface is obtained.

[0095] The UV-curable encapsulating resin UV-2 comprises the following components, by mass percentage: 1.0% of a silicone-epoxy resin composite modified polyurethane acrylate Si / EP-PUA-13, 4% of hexanediol diglycidyl ether, 10% of epoxy acrylate (CN120NS), 25% of a reactive monomer (trimethylolpropane triacrylate), 0.4% of octadecane dioic acid, 20% of a silane-modified resin (GPUA-1), 2.0% of p-toluenesulfonyl isocyanate, 5% of spherical silica powder, 1% of 4-acryloyloxybenzophenone, 1.4% of a photoinitiator (TPO), and 0.2% of a polymerization inhibitor (p-hydroxyanisole). Its preparation method is the same as that of UV-1 in Example 1.

[0096] The thermal conductivity, enthalpy, density, average thickness and compressive strength of the thermal runaway protection material RF-C15 prepared in this embodiment are shown in Table 2.

[0097] Example 4:

[0098] A rapid prototyping thermal runaway protection material comprises the following components, calculated by mass percentage: 85.7% potassium aluminum sulfate dodecahydrate, 7% polyvinyl alcohol, 0.3% eicosanedioic acid, and 7% UV-curable encapsulating resin UV-37%. The preparation method is as follows:

[0099] S1: Add 1714g of potassium aluminum sulfate dodecahydrate, 140g of polyvinyl alcohol, 6g of eicosanedioic acid, and 140g of UV-curable encapsulation resin UV-3 into a mixing kettle and mix well;

[0100] S2: The mixture was poured into a 227 mm × 160 mm × 30 mm mold and pressed into shape using a hydraulic press. The mass of the material was 1744 g and the pressure was 9.5 MPa.

[0101] S3: After the pressed material is demoulded, place it under 100mW / cm 2 The irradiation was carried out under a metal halide lamp for 80 seconds, with an irradiation dose of 8J / cm 2 After CNC (numerical control machine) grinding, the thermal runaway protection material RF-D30 with a smooth surface is obtained.

[0102] The UV-curable encapsulating resin UV-3 comprises the following components by mass percentage: 6.6% siloxane-epoxy resin composite modified polyurethane acrylate Si / EP-PUA-14, 10% epoxy acrylate (CN120NS), 10% reactive monomer (trimethylolpropane triacrylate), 12% reactive monomer (tripropylene glycol diacrylate), 0.3% eicosanedioic acid, 10% silane-modified resin (GPUA-2), 1% p-toluenesulfonyl isocyanate, 8% spherical silica powder, 0.5% photoinitiator 184, 1.5% photoinitiator TPO, and 0.1% polymerization inhibitor (p-hydroxyanisole). Its preparation method is the same as that of UV-1 in Example 1.

[0103] The thermal conductivity, enthalpy, density, average thickness and compressive strength of the thermal runaway protection material RF-D30 prepared in this example are shown in Table 2.

[0104] Comparative Example 1:

[0105] A rapid prototyping thermal runaway protection material comprises the following components, calculated by mass percentage: 30% citric acid, 37% magnesium chloride hexahydrate, 7.9% polyvinyl alcohol, 0.1% eicosanedioic acid, and 25% UV-curable encapsulating resin UV-1. The preparation method is as follows:

[0106] S1: Add 300g citric acid, 370g magnesium chloride hexahydrate, 79g polyvinyl alcohol, 1g eicosanedioic acid, and 250g UV curable encapsulation resin UV-1 into a mixing kettle and mix well;

[0107] S2: Pour the mixture into a 227 mm × 160 mm × 2 mm mold and use the mold to press the mold under a hydraulic press with a feed mass of 110 g and a pressure of 10.6 MPa;

[0108] S3: After the pressed material is demoulded, place it under 100mW / cm 2 The irradiation dose was 4J / cm2 for 40s under a metal halide lamp. 2 After CNC (numerical control machine) grinding, the thermal protection material RF-E2 with a smooth surface is obtained.

[0109] The UV curing encapsulation resin UV-1 and its preparation method are the same as those in Example 1.

[0110] The thermal conductivity, enthalpy, density, average thickness and compressive strength of the thermal runaway protection material RF-E2 prepared in this comparative example are shown in Table 2.

[0111] Comparative Example 2:

[0112] A rapid-prototyping thermal runaway protection material comprises the following components, calculated by mass percentage: 38% citric acid, 52% magnesium chloride hexahydrate, 7.9% polyvinyl alcohol, 0.1% eicosanedioic acid, and 12% UV-curable encapsulating resin. The preparation method, feed weight and pressure, and radiation dose are the same as those in Example 1.

[0113] The UV curing encapsulation resin UV-1 and its preparation method are the same as those in Example 1.

[0114] During the implementation process, it was found that it could not be formed.

[0115] Comparative Example 3:

[0116] A rapid-prototyping thermal runaway protection material comprises the following components, calculated by mass percentage: 30% citric acid, 52% magnesium chloride hexahydrate, 7.9% polyvinyl alcohol, 0.1% eicosanedioic acid, and 10% UV-curable encapsulating resin UV-4. The preparation method, feed weight and pressure, and radiation dose are the same as those in Example 1.

[0117] The UV curable encapsulation resin UV-4 comprises, by mass percentage, 1.2% of polyurethane acrylate Changxing 6148-J754, 1.0% of bisphenol A epoxy resin, 33% of epoxy acrylate, 9% of active monomer (trimethylolpropane triacrylate), 5% of active monomer (dipropylene glycol diacrylate), 0.2% of hexadecanedioic acid, 2% of silane modified resin (GPUA-1), 0.5% of p-toluenesulfonyl isocyanate, 5% of spherical silica powder, 1% of photoinitiator (184), 1% of 4-acryloyloxybenzophenone, 1% of photoinitiator (TPO), and 0.1% of polymerization inhibitor (p-hydroxyanisole). The preparation method is the same as that of UV-1 in Example 1.

[0118] The thermal conductivity, enthalpy, density, average thickness and compressive strength of the thermal runaway protection material RF-G2 prepared in this comparative example are shown in Table 2.

[0119] Table 2 shows the performance test results of the thermal runaway protection materials prepared in Examples 1-4 and Comparative Examples 1-3.

[0120] Table 2 Performance tests of embodiments and comparative examples Note: ① Thermal conductivity is tested according to ISO22007-2 ② Enthalpy of heat absorbing materials is tested by differential scanning calorimetry ③ Density = weight / volume ④ Compression strength is tested according to GB / T1041-2008

[0121] Comparative Example 1 falls outside the scope of the present invention. Its low enthalpy and thermal conductivity make it unable to meet the rapid heat absorption requirements of the battery during thermal runaway. The UV-curable encapsulation resin content in Comparative Example 2 is too low, making the resulting thermal protection material unformable. The UV-curable encapsulation resin in Comparative Example 3 uses unmodified polyurethane acrylate, resulting in poor adhesion to the heat-absorbing material and low compressive strength.

[0122] Test example

[0123] In order to test the thermal runaway effect of the thermal runaway protection material of the present invention, the following test platform was built: two soft-pack lithium iron phosphate batteries with an outer size of 227*160*7.25mm, a standard voltage of 3.3V, and a fully charged capacity of 20AH, numbered 1 and 2 respectively. The thermal runaway protection material prepared in the embodiment was sandwiched between battery No. 1 and battery No. 2. A heating plate with a power of 500W was attached to the right side of battery No. 1 and fixed with two upper and lower fixing fixtures. The two batteries were connected to a signal acquisition device to collect the voltage of the two batteries and the temperature of the bonding surface of the two batteries and the thermal runaway protection material. A blank sample without the thermal runaway protection material and a sample of 2mm glass fiber aerogel were also made. The structure of the signal acquisition device is shown in Figure 3.

[0124] The test steps are as follows: Place the heating plate and battery pack in an oven at 50±2°C for 12 hours. Power the heating plate and set the heating plate power to 100% while collecting battery voltage and temperature. When the voltage of battery No. 1 reaches 0V, stop heating and continue collecting battery temperature until the temperatures of both batteries drop below 50°C. Data collection stops at this point. The results are shown in Table 3.

[0125] Table 3 Application test of embodiments and comparative examples

[0126] The test shows that the blank sample did not use thermal runaway protection material. When the heating plate was heated for 222s, battery No. 1 was in complete thermal runaway, and the maximum temperature of the battery reached 385°C. The adjacent battery No. 2 also experienced thermal runaway. The sample using glass fiber aerogel had a faster internal temperature rise due to the thermal insulation effect of the aerogel. It was in complete thermal runaway in 196s, and the maximum temperature reached 475°C, which was 90°C higher than the blank sample. The adjacent battery No. 2 also experienced thermal runaway.

[0127] In the test samples using the 2mm, 5mm, 15mm and 30mm thermal runaway protection materials of the present invention, the adjacent No. 2 batteries did not have thermal runaway, and the time for the No. 1 battery voltage to drop to 0 was nearly twice as long as the blank sample. The maximum temperature of the battery during the entire test process was 284°C and the minimum was 232°C, which was more than 100°C lower than the blank sample temperature. After the test, the thermal conductivity of the thermal runaway protection material increased with increasing thickness, indicating that after the thickness increased, there was a surplus of material, and the protection material close to the No. 2 battery had a better thermal insulation effect. The maximum temperature of the adjacent No. 2 battery was 118°C and the minimum was 72°C, which was lower than the thermal runaway temperature of 150°C for lithium iron phosphate batteries reported in the literature (Mei Wenxin et al., Simulation study on high-temperature thermal runaway of large lithium iron phosphate batteries [J]. Energy Storage Science and Technology, 2021, 10(1): 202-209).

[0128] The 2mm thermal runaway protection materials of Comparative Examples 1-3 were used for testing. The thermal runaway protection material of Comparative Example 1 had a small enthalpy value and insufficient heat absorption, so it failed to quickly absorb the heat of Battery 1, and the ratio was not optimized. The thermal conductivity of the material after decomposition reached 0.151W / (mK), and the thermal insulation effect was also poor. Although the time for the voltage of Battery 1 to drop to 0 was delayed, thermal runaway eventually occurred. The thermal runaway protection material of Comparative Example 2 was not tested because it could not be formed. The thermal runaway protection material of Comparative Example 3 had a small compression strength, and the material was squeezed and cracked during the test, and then squeezed out, resulting in incomplete fitting between the material and the battery and a decrease in the amount of material. Although the time for the voltage of Battery 1 to drop to 0 was eventually extended, Battery 2 still experienced thermal runaway.

[0129] The above test results fully demonstrate that the thermal runaway protection material of the present invention first absorbs heat to quickly reduce the battery temperature, and then insulates to prevent heat from being transferred to adjacent batteries, which has a significant effect on preventing the spread of battery thermal runaway.

[0130] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A rapid prototyping thermal runaway protection material, characterized in that: The thermal runaway protection material comprises the following components by mass percentage: 71-95% of heat absorbing material, 1.5-12% of polyvinyl alcohol, 0-1% of long-chain alkyl diacid and 3-16% of UV curing encapsulation resin.

2. The thermal runaway protection material according to claim 1, characterized in that: The heat absorbing material includes one or more of sodium acetate trihydrate, ammonium ferric oxalate trihydrate, citric acid monohydrate, citric acid, oxalic acid dihydrate, anhydrous oxalic acid, malonic acid, magnesium sulfate heptahydrate, zinc sulfate heptahydrate, succinic acid, maleic acid, fumaric acid, sodium carbonate decahydrate, calcium chloride hexahydrate, aluminum nitrate nonahydrate, ammonium pentaborate octahydrate, ammonium ferric sulfate dodecahydrate, ferrous chloride tetrahydrate, ammonium oxalate monohydrate, sodium tetraborate decahydrate, sodium tetraborate pentahydrate, aluminum sulfate octahydrate, ammonium pentaborate, ammonium hydrogen borate tetrahydrate, boric acid, barium hydroxide octahydrate, pentahydrate and sodium silicate, silicic acid, hydrated silicic acid, ammonium aluminum sulfate dodecahydrate, hydrated sodium aluminum silicate, potassium aluminum sulfate dodecahydrate, sodium sulfate decahydrate, copper sulfate heptahydrate, ferrous sulfate heptahydrate, cobalt chloride hexahydrate, and calcium sulfate dihydrate.

3. The thermal runaway protection material according to claim 1, characterized in that: The UV curing encapsulation resin comprises the following components by mass percentage: 25-70% of siloxane-epoxy resin composite modified polyurethane acrylate, 0-5% of epoxy resin, 5-40% of epoxy acrylate, 0-5% of acrylic acid, 5-30% of active monomer, 0-1% of long-chain alkyl diacid, 0-25% of silane modified resin, 0.1-3% of dehydrating agent, 0-10% of spherical silicon powder, 0.1-3% of photoinitiator and 0.01-0.3% of polymerization inhibitor.

4. The thermal runaway protection material according to claim 3, characterized in that: The preparation method of the UV curing encapsulation resin is as follows: adding the materials in the components into a reactor according to a proportion, maintaining 50-60° C. and stirring for 2-3 hours, and finally adding a dehydrating agent, stirring for 10-30 minutes to obtain the UV curing encapsulation resin.

5. The thermal runaway protection material according to claim 3, characterized in that: The epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, bisphenol S epoxy resin, epoxy soybean oil, cardanol modified epoxy resin, trimethylolpropane triglycidyl ether, hexanediol diglycidyl ether, and phenyl glycidyl ether; The epoxy acrylate includes CN104 NS or CN120 NS of Sartomer; The active monomers include one or more of isobornyl acrylate, 2-cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, isobornyl methacrylate, and tetrahydrofurfuryl methacrylate; The long-chain alkyl diacid includes one or more of dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosanedioic acid.

6. The thermal runaway protection material according to claim 3, characterized in that: The silane-modified resin includes one or more of silane-modified polyether resin, silane-modified polyacrylate resin, silane-modified polyurethane resin, silane-modified polyester resin, and alkoxy silicone resin.

7. The thermal runaway protection material according to claim 3, characterized in that: The dewatering agent is p-toluenesulfonyl isocyanate; The spherical silicon powder is a spherical silicon powder with D50=50-300μm and D100<500μm; The photoinitiator includes one or more of 4-benzoyl-4'-methyl-diphenyl sulfide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphosphonic acid ethyl ester, bis(2,4,6-trimethylbenzyl acyl)phenylphosphine oxide, benzoin dimethyl ether, 2-methyl-1-(4-methylmercaptophenyl)-2-morpholine-1-propanone, polymerized [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone], 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, 1-(9,9-dibutyl-9H-fluorene-2-yl)-2-methyl-2-morpholine-4-yl-propane-1-one, 1-hydroxycyclohexyl benzophenone, 4-acryloxybenzophenone, and methyl o-benzoylbenzoate; The polymerization inhibitor is p-hydroxyanisole; The polyvinyl alcohol is in powder form.

8. The thermal runaway protection material according to claim 3, characterized in that: The preparation method of the siloxane-epoxy resin composite modified polyurethane acrylate comprises the following steps: S1: adding diisocyanate and hydroxy acrylate in a molar ratio of 1:1 into reactor A, adding 0.01-0.2% of the total mass of diisocyanate and hydroxy acrylate as a catalyst dibutyltin dilaurate, and 0.01-0.2% of the total mass of diisocyanate and hydroxy acrylate as a polymerization inhibitor p-hydroxyanisole, heating to 40-60° C. for reaction for 1-3 hours to obtain a semi-adduct of diisocyanate and hydroxyethyl acrylate, and calculating the theoretical NCO equivalent; S2: adding epoxy resin and mercaptosilane coupling agent into reactor B in a molar ratio of epoxy bond to mercapto group of 1:1, adding catalyst triethylamine in an amount of 0.01-0.2% of the total mass of epoxy resin and mercaptosilane coupling agent, heating to 70-90° C. for reaction for 1-3 hours to obtain siloxane-modified epoxy resin, and calculating the theoretical hydroxyl equivalent; S3: According to the calculation method of NCO equivalent: hydroxyl equivalent = semi-adduct mass: siloxane-modified epoxy resin mass, a set amount of siloxane-modified epoxy resin is added to reactor A, and 0.01-0.2% of the total mass of the siloxane-modified epoxy resin is added as a catalyst dibutyltin dilaurate and 0.01-0.2% of the total mass of the siloxane-modified epoxy resin as an inhibitor of hydroxyl radicals are added. 1-aminobenzyl ether, maintaining 60-80° C. with stirring for reaction for 2-8 hours, until the isocyanate reaction is complete, to obtain the siloxane-epoxy resin modified polyurethane acrylate.

9. The thermal runaway protection material according to claim 8, characterized in that: In step S1, the diisocyanate includes one or more of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, xylylene diisocyanate, trimethylhexane diisocyanate, 1,5-naphthalene diisocyanate, and diphenylmethane diisocyanate; The hydroxy acrylate includes one or more of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, and 4-hydroxybutyl acrylate.

10. The thermal runaway protection material according to claim 8, characterized in that: In step S2, the mercaptosilane coupling agent includes one or more of mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptopropylmethyldimethoxysilane, and mercaptopropylmethyldiethoxysilane.

11. The thermal runaway protection material according to claim 8, characterized in that: In step S1, 0-30% of the total mass of diisocyanate and hydroxy acrylate is added to the acrylate monomer; in step S2, 0-30% of the total mass of epoxy resin and mercaptosilane coupling agent is added to the acrylate monomer; or In step S1, 0-30% of the total mass of diisocyanate and hydroxy acrylate is added to the acrylate monomer; in step S3, 0-30% of the total mass of siloxane-modified epoxy resin is added to the acrylate monomer; or In step S2, 0-30% of the total mass of the epoxy resin and the mercaptosilane coupling agent is added to the acrylate monomer; in step S3, 0-30% of the total mass of the siloxane-modified epoxy resin is added to the acrylate monomer; or In step S1, 0-30% of the total mass of diisocyanate and hydroxy acrylate is added to the acrylate monomer; in step S2, 0-30% of the total mass of epoxy resin and mercaptosilane coupling agent is added to the acrylate monomer; in step S3, 0-30% of the total mass of siloxane-modified epoxy resin is added to the acrylate monomer. The acrylate monomer is an acrylate monomer with 1-6 functions and does not contain a hydroxyl structure, including one or more of isobornyl acrylate, 2-cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, isobornyl methacrylate, and tetrahydrofurfuryl methacrylate.

12. The thermal runaway protection material according to claim 8, characterized in that: In step S1, 0-30% of the total weight of diisocyanate and hydroxy acrylate is added to the acrylate monomer; or In step S2, 0-30% of the total weight of the epoxy resin and the mercaptosilane coupling agent is added to the acrylate monomer; or In step S3, 0-30% of the total mass of the siloxane-modified epoxy resin is added with an acrylate monomer; The acrylate monomer is an acrylate monomer with 1-6 functions and does not contain a hydroxyl structure, including one or more of isobornyl acrylate, 2-cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, isobornyl methacrylate, and tetrahydrofurfuryl methacrylate.

13. The thermal runaway protection material according to claim 8, characterized in that: The preparation method of the thermal runaway protection material is as follows: All components are added into a mixing kettle, mixed evenly, and then pressurized in a mold, and cured by ultraviolet light to obtain a thermal runaway protection material.

14. The thermal runaway protection material according to claim 13, characterized in that: The ultraviolet lamp is a high-pressure mercury lamp or a metal halide lamp.

15. The thermal runaway protection material according to claim 13, characterized in that: The ultraviolet lamp is an ultraviolet lamp in the 365-405nm band.

16. The thermal runaway protection material according to any one of claims 1 to 15, characterized in that: The thermal runaway protection material is cut according to the structure of the battery pack and packaged in a sealed and pressure-resistant shell.

17. The thermal runaway protection material according to any one of claims 1 to 15, characterized in that: The thermal runaway protection material is used alone as a thermal runaway protection material, or is used in combination with a thermal insulation material or a physical thermal insulation structure to form a thermal protection system.

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