Compound lithium ion battery fire extinguishing agent and preparation method thereof

Abstract

The invention relates to the technical field of lithium ion battery fire extinguishing agents, and discloses a compound lithium ion battery fire extinguishing agent and a preparation method thereof.The compound lithium ion battery fire extinguishing agent is prepared from, by mass, 30-35 parts of vermiculite, 5-7 parts of fire extinguishing filler, 6-8 parts of modified zeolite, 0.5-1 part of a stabilizer, 1.5-2 parts of a dispersing agent, 1-2 parts of a thickening agent, 1-3 parts of a foaming agent and 40-50 parts of water. The fire extinguishing filler can form a barrier layer on the surface of the battery to prevent oxygen and heat transfer and achieve the fire extinguishing purpose, and starch and polydopamine in the fire extinguishing filler can form compact carbon layers, so that wrapped combustible molecules are distributed among the carbon layers, oxygen is further isolated, and the fire extinguishing efficiency is improved; the modified zeolite can complete fire extinguishing through a physical and chemical synergistic effect, and can form silicon dioxide to be distributed on the surface of the zeolite in the fire extinguishing process, so that the situation that the zeolite is subjected to thermal shock and thermal stress to cause collapse of a zeolite framework and influence the fire extinguishing performance is avoided.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of lithium ion battery fire extinguishing agents, in particular to a compounded lithium ion battery fire extinguishing agent and a preparation method thereof. BACKGROUND

[0002] The lithium ion battery is a rechargeable battery adopting graphite or other carbon materials as a negative electrode and a lithium-containing compound as a positive electrode. Since the lithium ion battery relies on internal chemical reactions for charging and discharging, when short circuit or overheating occurs, the temperature of the lithium ion battery rapidly rises, the battery appears electrolyte decomposition, lithium deposition, oxidation-reduction reaction and the like, a large amount of combustible gas and heat are released, and thus a fire is triggered. At present, when a lithium battery thermal runaway triggers a fire, a water-based fire extinguishing agent, a dry powder fire extinguishing agent, a carbon dioxide fire extinguishing agent, a heptafluoropropane fire extinguishing agent, an aerosol fire extinguishing agent and a perfluorohexanone fire extinguishing agent and the like are used to extinguish the lithium battery fire source.

[0003] The existing fire extinguishing agent has the effects of isolating oxygen and reducing temperature, but cannot completely terminate the chemical reactions in the battery. After the fire is extinguished, high temperature and active substances exist in the battery, thermal runaway occurs again, and thus the fire reignites. The addition of montmorillonite and zeolite in the battery fire extinguishing agent can form a barrier layer on the surface of the battery, prevent the transmission of oxygen and heat, and adsorb a large amount of burning free radicals to interrupt the chain reaction of combustion, so that the fire extinguishing agent has the performances of fast fire extinguishing and no reignition, and can complete the fire extinguishing in a short time. However, in the fire extinguishing process, the expanded montmorillonite barrier layer is easy to break under high temperature, which affects the fire extinguishing efficiency, and the zeolite is easy to be subjected to thermal shock and thermal stress to cause the collapse of the zeolite framework, which affects the fire extinguishing performance. SUMMARY

[0004] The application provides a compounded lithium ion battery fire extinguishing agent and a preparation method thereof, and solves the problem that the lithium ion battery fire extinguishing agent cannot completely terminate the chemical reactions in the battery, and the battery reignites again after the fire is extinguished due to the existence of high temperature and active substances in the battery.

[0005] The technical scheme of the application is as follows:

[0006] The compounded lithium ion battery fire extinguishing agent comprises the following raw materials in parts by mass: 30-35 parts of vermiculite, 5-7 parts of fire extinguishing filler, 6-8 parts of modified zeolite, 0.5-1 part of stabilizer, 1.5-2 parts of dispersing agent, 1-2 parts of thickening agent, 1-3 parts of foaming agent and 40-50 parts of water.

[0007] The fire extinguishing filler is obtained by mixing the following components: graphene oxide intercalated montmorillonite, dopamine surface modification, amphoteric starch, saponin and potassium perfluorobutylsulfonate.

[0008] The modified zeolite is obtained by mixing the following components: hydrochloric acid activated zeolite, iron chloride hexahydrate and organosilicon.

[0009] A preparation method of a complex lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0010] Mixing vermiculite, fire extinguishing filler, modified zeolite and water, stirring uniformly, adding stabilizer, dispersant, thickening agent, foaming agent, stirring at 500-700 r / min for 30-50 min, to obtain the battery fire extinguishing agent.

[0011] Further, the vermiculite is expanded vermiculite, and the particle size is 25-35 μm.

[0012] Further, the stabilizer is selected from ethylene glycol-butyl ether or ethylene glycol.

[0013] Further, the dispersant is selected from polyvinylpyrrolidone or alkyl polyoxyethylene ether.

[0014] Further, the thickening agent is carboxymethyl cellulose.

[0015] Further, the foaming agent is selected from sodium dodecyl sulfonate or pine alcohol oil.

[0016] Further, the fire extinguishing filler is prepared by the following steps:

[0017] A1. Adding graphene oxide and montmorillonite into deionized water, heating to 50-60℃, ultrasonic treatment at 40-60 KHz for 5-6 h, filtering, washing, drying, to obtain a composite;

[0018] A2. Adding the composite into Tris-HCl buffer solution, stirring uniformly, adding dopamine, continuing to stir, filtering, washing, drying, to obtain a modified composite;

[0019] A3. Mixing starch and sodium silicate solution, stirring uniformly, standing, adding dodecyl succinic anhydride and ethanol, stirring uniformly, sealing, continuing to stand, heating to 65-75℃ for 1-3 h, cooling to room temperature, taking out, washing, drying, to obtain amphoteric starch;

[0020] A4. Adding the modified composite and amphoteric starch into ethanol, stirring uniformly, adding saponin and potassium perfluorobutyl sulfonate, stirring at room temperature, heating, continuing to stir until the solvent volatilizes, to obtain the fire extinguishing filler.

[0021] Further, in the above A1 reaction process, the ultrasonic treatment can destroy the interlayer structure of graphene oxide, form intercalated graphene oxide between the layers of montmorillonite, and the silicon hydroxyl in the interlayer of montmorillonite can be combined with the carboxyl in the interlayer graphene oxide through chemical bonds, so that the graphene oxide and montmorillonite are connected through covalent bond and hydrogen bond to form graphene oxide intercalated montmorillonite, i.e. the composite.

[0022] Further, in the above-mentioned A2 reaction process, dopamine can self-polymerize on the surface of the complex to form polydopamine in the Tris-HCl buffer solution, forming a polydopamine-modified complex, i.e., a modified complex.

[0023] Further, in the above-mentioned A3 reaction process, the hydroxyl groups in the starch can react with the succinic anhydride groups of dodecyl succinic anhydride, allowing dodecyl succinic anhydride to be grafted onto the starch molecular chain, introducing lipophilic alkenyl long chains and hydrophilic carboxylic acid groups into the starch molecular structure, and obtaining amphiphilic starch with hydrophilic and lipophilic properties.

[0024] Further, in the above-mentioned A4 reaction process, the modified complex surface contains a large number of phenolic hydroxyl groups, has excellent adhesion properties, and can be combined with amphiphilic starch through chemical bonds, allowing the amphiphilic starch-coated modified complex surface to further combine with saponin and potassium perfluorobutyl sulfonate through chemical bonds, forming a mixture as a fire extinguishing filler.

[0025] Further, in step A1, the amount ratio of graphene oxide, montmorillonite, and deionized water is (1-2) g:(5.5-5.9) g:(130-170) mL.

[0026] Further, in step A2, the amount ratio of the complex, Tris-HCl buffer solution, and dopamine is (3-4) g:(80-120) mL:(0.7-0.9) g.

[0027] Further, in step A3, the amount ratio of starch, sodium silicate solution, dodecyl succinic anhydride, and ethanol is (4-6) g:(2-4) mL:(0.5-0.7) mL:(0.5-0.7) mL.

[0028] Further, in step A4, the amount ratio of the modified complex, amphiphilic starch, ethanol, saponin, and potassium perfluorobutyl sulfonate is (5-6) g:(2-2.4) g:(45-55) mL:(8-10) g:(9-11) g.

[0029] Further, the modified zeolite is prepared by the following steps:

[0030] B1. Iron chloride hexahydrate is added to hydrochloric acid, stirred uniformly, and zeolite is activated by adding hydrochloric acid, ultrasonic treatment, and then filtered, washed, and dried to obtain zeolite loaded with iron ions;

[0031] B2. Organic silicon is added to ethanol and deionized water, stirred uniformly, and the pH is adjusted to 8-9 by adding ammonia water, then the zeolite loaded with iron ions is added, and stirred at 45-55°C until it becomes gelatinous, then filtered, washed, and dried to obtain modified zeolite.

[0032] Further, in the above B1 reaction process, the iron ions in the ferric chloride hexahydrate can be combined with the active groups in the hydrochloric acid activated zeolite, so that the iron ions are embedded into the zeolite framework, and the zeolite loaded with iron ions is obtained.

[0033] Further, in the above B2 reaction process, the silicon hydroxyl generated by the hydrolysis of the organosilicon can be combined with the active groups on the surface of the zeolite loaded with iron ions, so that the zeolite loaded with iron ions is embedded into the organosilicon gel, and the modified zeolite is obtained.

[0034] Further, in step B1, the amount ratio of the ferric chloride hexahydrate, the hydrochloric acid and the hydrochloric acid activated zeolite is (1.2-1.3) g:(20-30) mL:(4-6) g.

[0035] Further, in step B2, the amount ratio of the organosilicon, the ethanol, the deionized water and the zeolite loaded with iron ions is (7-8) g:(55-65) mL:(15-25) mL:(3-4) g.

[0036] Further, the organosilicon is tetraethyl orthosilicate.

[0037] Further, the hydrochloric acid activated zeolite is prepared by the following steps: adding the zeolite into the hydrochloric acid, ultrasonic treatment, standing, filtering, washing, drying, and obtaining the hydrochloric acid activated zeolite.

[0038] Further, in the above reaction process, the basic groups on the surface of the zeolite framework are neutralized and reduced by the hydrochloric acid, and the hydrogen ions are introduced into the zeolite framework, so that the content of the acidic functional groups on the surface of the zeolite is increased, and some impurities and amorphous substances in the pores of the zeolite are dissolved, so that the internal pores of the zeolite are increased, the pore resistance is reduced, and the embedding of the iron ions into the zeolite framework is facilitated.

[0039] Further, the amount ratio of the zeolite and the hydrochloric acid is (4-6) g:(20-30) mL.

[0040] Further, the particle size of the zeolite is 6-7 μm, and the zeolite is purchased from Linyi Jinyuan Environmental Protection Equipment Co., Ltd.

[0041] The present application has the following beneficial effects:

[0042] (1) In the technical solution of the present invention, graphene oxide and montmorillonite are connected by covalent bonds and hydrogen bonds to form graphene oxide intercalated montmorillonite. On the one hand, graphene oxide intercalated montmorillonite forms a layered material, which can form a barrier layer to prevent the transfer of oxygen and heat, block the combustion of lithium-ion batteries, and achieve the purpose of fire extinguishing. On the other hand, graphene oxide and montmorillonite can capture free radicals in the battery combustion reaction, thereby improving the fire extinguishing efficiency. Graphene oxide serves as a support structure for montmorillonite, which improves the mechanical strength of montmorillonite after expansion and prevents the barrier layer of the expanded montmorillonite from rupturing at high temperatures, leading to reignition and affecting the fire extinguishing efficiency. Dopamine can self-polymerize on the surface of the composite to form polydopamine, forming a modified composite, which is conducive to forming a fire extinguishing layer in the lithium-ion battery.

[0043] (2) In the technical solution of the present invention, the surface of the modified composite coated with amphiphilic starch is chemically bonded with saponin and potassium perfluorobutanesulfonate to form a mixture as a fire extinguishing filler. On the one hand, saponin and potassium perfluorobutanesulfonate enable the fire extinguishing agent to form a uniform water film on the surface of the battery, blocking oxygen and not wetting the battery, and having a good fire extinguishing effect. On the other hand, the amphiphilic starch in the modified composite contains hydrophobic carbon chains that can repel water molecules, capture combustible molecules and wrap them, forming a microcapsule structure that is deposited on the surface of graphene oxide intercalated montmorillonite. , preventing the continued combustion of combustibles, interrupting the chain reaction of combustion free radicals, and achieving the purpose of fire extinguishing. Its hydrophilic groups can be adsorbed into the water film covering the surface of the battery, so that the graphene oxide intercalated montmorillonite complex and the microcapsule structure form a dense barrier layer on the surface of the battery, preventing oxygen and heat transfer, and achieving the purpose of fire extinguishing. In addition, as the temperature rises, the starch and polydopamine contained in the fire extinguishing filler can form a dense carbon layer, so that the wrapped combustible molecules are distributed between the carbon layers, further isolating oxygen, avoiding re-ignition, and improving the fire extinguishing efficiency.

[0044] (3) In the technical solution of the present invention, iron ions are embedded in the hydrochloric acid activated zeolite skeleton. On the one hand, the hydrochloric acid activated zeolite has a porous structure and a large specific surface area, which can adsorb a large number of combustion free radicals and consume the free radicals in the combustion reaction. The number of free radicals is sharply reduced, the chain reaction of combustion is interrupted, and the purpose of fire extinguishing is achieved. On the other hand, the loaded iron ions can react with the active free radicals in the flame, inhibit the spread of flame through chemical action, and better complete the fire extinguishing through physical and chemical synergistic effects.

[0045] (4) In the technical solution of the present invention, zeolite loaded with iron ions is embedded in silicone gel to obtain modified zeolite. During the fire extinguishing process, the silicone on the surface of the modified zeolite is dehydrated to form high-temperature resistant silica, which enhances the stability and heat resistance of the fire extinguishing agent and reduces the viscosity and conductivity. The formed silica is distributed on the surface of the zeolite, preventing the zeolite from being subjected to thermal shock and thermal stress, which may cause the zeolite skeleton to collapse and affect the fire extinguishing performance. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0047] The raw materials used in the embodiments of the present application are shown as follows, and all the reagents used are analytical grade.

[0048] The vermiculite is expanded vermiculite, and the particle size is 30 μm.

[0049] The stabilizer is ethylene glycol-butyl ether, the dispersant is polyvinylpyrrolidone, the thickening agent is carboxymethyl cellulose, and the foaming agent is sodium dodecyl sulfonate.

[0050] The graphene oxide has a thickness of 20 nm, an interlayer spacing of 0.6 nm, and a particle size of 10 μm.

[0051] The montmorillonite is quaternary ammonium salt modified montmorillonite, and has an apparent density of 0.3 g / cm 3 , a thickness of 25 nm, and an interlayer spacing of 2.4 nm, and is purchased from Zhejiang Fenghong Clay Chemical Co., Ltd.

[0052] The starch is cassava starch, and is purchased from Shanghai Maikelin Biochemical Technology Co., Ltd.

[0053] The zeolite has a particle size of 6.5 μm, and is purchased from Linyi Jinyuan Environmental Protection Equipment Co., Ltd.

[0054] The organosilicon is tetraethyl orthosilicate.

[0055] The hydrochloric acid activated zeolite is prepared by the following steps:

[0056] 5 g of zeolite is added to 25 mL of hydrochloric acid with a concentration of 0.25 mol / L, ultrasonic treatment is performed at 40 KHz for 15 min, standing is performed at 25℃ for 24 h, filtration is performed, deionized water washing is performed until the washing liquid has a neutral pH, and drying is performed in an oven at 105℃ for 15 min to obtain the hydrochloric acid activated zeolite.

[0057] Example 1

[0058] The compound type lithium ion battery fire extinguishing agent comprises the following raw materials in parts by mass: expanded vermiculite 30 parts, fire extinguishing filler 5 parts, modified zeolite 6 parts, ethylene glycol-butyl ether 0.5 part, polyvinylpyrrolidone 1.5 parts, carboxymethyl cellulose 1 part, sodium dodecyl sulfonate 1 part, and water 40 parts.

[0059] The preparation method of the compound type lithium ion battery fire extinguishing agent comprises the following preparation steps:

[0060] Expanded vermiculite, fire extinguishing filler, modified zeolite and water were mixed and stirred evenly, ethylene glycol monobutyl ether, polyvinyl pyrrolidone, carboxymethyl cellulose and sodium lauryl sulfate were added, and the mixture was stirred at 500 r / min for 30 minutes to obtain a battery fire extinguishing agent.

[0061] The fire extinguishing filler is specifically prepared by the following steps:

[0062] A1. 1 g of graphene oxide and 5.5 g of quaternary ammonium salt-modified montmorillonite were added to 130 mL of deionized water, heated to 50°C, and sonicated at 40 kHz for 5 h. The mixture was filtered, washed three times with deionized water, and dried in an oven at 60°C for 15 min to obtain a composite.

[0063] A2. 3 g of the complex was added to 80 mL of Tris-HCl buffer (pH 8.5), stirred at 25°C and 2000 rpm for 20 min, then 0.7 g of dopamine was added. The mixture was stirred at 30°C and 2000 rpm for 2 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min to obtain the modified complex.

[0064] A3. 4 g of cassava starch was mixed with 2 mL of a 20% sodium silicate solution, stirred, and allowed to stand at 25°C for 1 hour. 0.5 mL of dodecenylsuccinic anhydride and 0.5 mL of ethanol were added, stirred, and sealed. After standing at 25°C for 3 hours, the mixture was heated to 65°C for 1 hour, cooled to room temperature, removed, washed three times with ethanol, and dried in a 70°C oven for 10 minutes to obtain amphoteric starch.

[0065] A4. Add 5 g of the modified composite and 2 g of amphoteric starch to 45 mL of ethanol and stir evenly. Then add 8 g of saponin and 9 g of potassium perfluorobutanesulfonate. Stir at 25°C for 1.5 h. Then raise the temperature to 70°C and continue stirring until the solvent evaporates to obtain a fire-extinguishing filler.

[0066] The modified zeolite is specifically prepared by the following steps:

[0067] B1. 1.2 g of ferric chloride hexahydrate was added to 20 mL of 0.25 mol / L hydrochloric acid, stirred, and 4 g of hydrochloric acid was added to activate the zeolite. The mixture was ultrasonically treated at 40 kHz for 10 min, allowed to stand at 25 ° C for 2 h, filtered, washed three times with deionized water, and dried in an oven at 80 ° C for 10 min to obtain an iron ion-loaded zeolite.

[0068] B2. 7 g of tetraethyl orthosilicate was added to 55 mL of ethanol and 15 mL of deionized water, stirred uniformly, 45% ammonia water was added to adjust the pH to 8, stirred uniformly, 3 g of zeolite loaded with iron ions was added, stirred at 45℃ until gelling, filtered, washed with deionized water 3 times, dried in an oven at 70℃ for 10 min, to obtain the modified zeolite.

[0069] Example 2

[0070] A compounded lithium ion battery fire extinguishing agent, comprising the following mass parts of raw materials: expanded vermiculite 33 parts, fire extinguishing filler 6 parts, modified zeolite 7 parts, ethylene glycol-butyl ether 0.8 parts, polyvinylpyrrolidone 1.8 parts, carboxymethyl cellulose 1.5 parts, sodium dodecyl sulfonate 2 parts, water 45 parts;

[0071] A preparation method of a compounded lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0072] The expanded vermiculite, fire extinguishing filler, modified zeolite and water are mixed and stirred uniformly, ethylene glycol-butyl ether, polyvinylpyrrolidone, carboxymethyl cellulose, and sodium dodecyl sulfonate are added, stirred at 600 r / min for 40 min, to obtain the battery fire extinguishing agent.

[0073] The fire extinguishing filler is specifically prepared by the following steps:

[0074] A1. 1.5 g of graphene oxide and 5.7 g of quaternary ammonium salt modified montmorillonite were added to 150 mL of deionized water, heated to 55℃, ultrasonically treated at 50 KHz for 5.5 h, filtered, washed with deionized water 3 times, dried in an oven at 60℃ for 15 min, to obtain the composite;

[0075] A2. 3.5 g of the composite was added to 100 mL of Tris-HCl buffer with pH 8.5, stirred at 25℃, 2000 r / min for 20 min, 0.8 g of dopamine was added, stirred at 30℃, 2000 r / min for 2 h, after filtration, washed with deionized water 3 times, dried in an oven at 70℃ for 10 min, to obtain the modified composite;

[0076] A3. 5 g of cassava starch and 3 mL of 20% sodium silicate solution were mixed, stirred uniformly, placed at 25℃ for 1 h, 0.6 mL of dodecenyl succinic anhydride and 0.6 mL of ethanol were added, stirred uniformly, sealed, placed at 25℃ for 3 h, then heated to 70℃ and reacted for 2 h, cooled to room temperature, taken out, washed with ethanol 3 times, dried in an oven at 70℃ for 10 min, to obtain the amphoteric starch;

[0077] A4. 5.5 g of the modified composite and 2.2 g of the amphoteric starch were added to 50 mL of ethanol, stirred uniformly, 9 g of saponin and 10 g of potassium perfluorobutyl sulfonate were added, stirred at 25°C for 1.5 h, the temperature was raised to 70°C, and the stirring was continued until the solvent evaporated, to obtain the fire extinguishing filler.

[0078] The modified zeolite was prepared by the following steps:

[0079] B1. 1.25 g of ferric chloride hexahydrate was added to 25 mL of hydrochloric acid with a concentration of 0.25 mol / L, stirred uniformly, 5 g of hydrochloric acid activated zeolite was added, ultrasonically treated at 40 KHz for 10 min, and then left to stand at 25°C for 2 h, filtered, washed with deionized water for 3 times, and dried in an oven at 80°C for 10 min, to obtain the zeolite loaded with iron ions;

[0080] B2. 7.5 g of tetraethyl orthosilicate was added to 60 mL of ethanol and 20 mL of deionized water, stirred uniformly, the pH was adjusted to 8.5 by adding 45% ammonia water, stirred uniformly, 3.5 g of the zeolite loaded with iron ions was added, stirred at 50°C until it became gel, filtered, washed with deionized water for 3 times, and dried in an oven at 70°C for 10 min, to obtain the modified zeolite.

[0081] Example 3

[0082] A compounded lithium ion battery fire extinguishing agent, comprising the following raw materials in mass parts: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, modified zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinylpyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, and water 50 parts;

[0083] A preparation method of a compounded lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0084] The expanded vermiculite, the fire extinguishing filler, the modified zeolite and the water were mixed and stirred uniformly, the ethylene glycol-butyl ether, the polyvinylpyrrolidone, the carboxymethyl cellulose and the sodium dodecyl sulfonate were added, and stirred at 700 r / min for 50 min, to obtain the battery fire extinguishing agent.

[0085] The fire extinguishing filler was prepared by the following steps:

[0086] A1. 2 g of graphene oxide and 5.9 g of quaternary ammonium salt modified montmorillonite were added to 170 mL of deionized water, the temperature was raised to 60°C, and ultrasonically treated at 60 KHz for 6 h, filtered, washed with deionized water for 3 times, and dried in an oven at 60°C for 15 min, to obtain the composite;

[0087] A2. 4g of the composite was added to 120 mL of Tris-HCl buffer with pH 8.5, stirred at 25℃ and 2000 r / min for 20 min, 0.9g of dopamine was added, stirred at 30℃ and 2000 r / min for 2h, after filtration, washed with deionized water for 3 times, dried in an oven at 70℃ for 10 min, to obtain a modified composite;

[0088] A3. 6g of cassava starch and 4 mL of 20% sodium silicate solution were mixed and stirred uniformly, and then placed at 25℃ for 1h, 0.7 mL of dodecenyl succinic anhydride and 0.7 mL of ethanol were added and stirred uniformly, sealed, and then placed at 25℃ for 3h, and then heated to 75℃ for reaction for 3h, cooled to room temperature, taken out, washed with ethanol for 3 times, and dried in an oven at 70℃ for 10 min, to obtain an amphoteric starch;

[0089] A4. 6g of the modified composite and 2.4g of the amphoteric starch were added to 55 mL of ethanol, stirred uniformly, 10g of saponin and 11g of potassium perfluorobutyl sulfonate were added, stirred at 25℃ for 1.5h, heated to 70℃, and continued to stir until the solvent volatilized, to obtain a fire extinguishing filler.

[0090] The modified zeolite was prepared by the following steps:

[0091] B1. 1.3g of ferric chloride hexahydrate was added to 30 mL of hydrochloric acid with a concentration of 0.25 mol / L, stirred uniformly, 6g of hydrochloric acid activated zeolite was added, ultrasonically treated at 40KHz for 10 min, placed at 25℃ for 2h, filtered, washed with deionized water for 3 times, and dried in an oven at 80℃ for 10 min, to obtain a zeolite loaded with iron ions;

[0092] B2. 8g of tetraethyl orthosilicate was added to 65 mL of ethanol and 25 mL of deionized water, stirred uniformly, 45% ammonia water was added to adjust the pH to 9, stirred uniformly, 4g of the zeolite loaded with iron ions was added, stirred at 55℃ until gel-like, filtered, washed with deionized water for 3 times, and dried in an oven at 70℃ for 10 min, to obtain a modified zeolite.

[0093] Comparative Example 1

[0094] A compounded lithium ion battery fire extinguishing agent, comprising the following raw materials in mass parts: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, modified zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinylpyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, and water 50 parts;

[0095] A preparation method of a compounded lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0096] Mixing the expanded vermiculite, fire extinguishing filler, modified zeolite and water, stirring uniformly, adding ethylene glycol-butyl ether, polyvinylpyrrolidone, carboxymethyl cellulose, sodium dodecyl sulfonate, stirring at 700 r / min for 50 min, to obtain the battery fire extinguishing agent.

[0097] The fire extinguishing filler is specifically prepared by the following steps:

[0098] A1. Mixing 2 g of graphene oxide and 5.9 g of quaternary ammonium salt modified montmorillonite to obtain a composite;

[0099] A2. Adding 4 g of the composite to 120 mL of Tris-HCl buffer with pH 8.5, stirring at 25℃, 2000 r / min for 20 min, adding 0.9 g of dopamine, stirring at 30℃, 2000 r / min for 2 h, filtering, washing with deionized water for 3 times, and drying in a 70℃ oven for 10 min to obtain a modified composite;

[0100] A3. Mixing 6 g of cassava starch and 4 mL of 20% sodium silicate solution, stirring uniformly, standing at 25℃ for 1 h, adding 0.7 mL of dodecenyl succinic anhydride and 0.7 mL of ethanol, stirring uniformly, sealing, standing at 25℃ for 3 h, then increasing the temperature to 75℃ and reacting for 3 h, cooling to room temperature, taking out, washing with ethanol for 3 times, and drying in a 70℃ oven for 10 min to obtain an amphoteric starch;

[0101] A4. Adding 6 g of the modified composite and 2.4 g of the amphoteric starch to 55 mL of ethanol, stirring uniformly, adding 10 g of saponin and 11 g of potassium perfluorobutyl sulfonate, stirring at 25℃ for 1.5 h, increasing the temperature to 70℃, and continuing to stir until the solvent volatilizes to obtain the fire extinguishing filler.

[0102] The modified zeolite is specifically prepared by the following steps:

[0103] B1. Adding 1.3 g of iron chloride hexahydrate to 30 mL of hydrochloric acid with a concentration of 0.25 mol / L, stirring uniformly, adding 6 g of hydrochloric acid activated zeolite, ultrasonic treating at 40 KHz for 10 min, standing at 25℃ for 2 h, filtering, washing with deionized water for 3 times, and drying in a 80℃ oven for 10 min to obtain the zeolite loaded with iron ions;

[0104] B2. Adding 8 g of tetraethyl orthosilicate to 65 mL of ethanol and 25 mL of deionized water, stirring uniformly, adding 45% ammonia water to adjust the pH to 9, stirring uniformly, adding 4 g of the zeolite loaded with iron ions, stirring at 55℃ until gel is formed, filtering, washing with deionized water for 3 times, and drying in a 70℃ oven for 10 min to obtain the modified zeolite.

[0105] Comparative Example 2

[0106] A complex lithium ion battery fire extinguishing agent, comprising the following mass parts of raw materials: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, modified zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinyl pyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, water 50 parts;

[0107] A preparation method of a complex lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0108] Mixing expanded vermiculite, fire extinguishing filler, modified zeolite and water, stirring uniformly, adding ethylene glycol-butyl ether, polyvinyl pyrrolidone, carboxymethyl cellulose, sodium dodecyl sulfonate, stirring at 700 r / min for 50 min, to obtain a battery fire extinguishing agent.

[0109] The fire extinguishing filler is specifically prepared by the following steps:

[0110] A1. 2g of graphene oxide and 5.9g of quaternary ammonium salt modified montmorillonite are added to 170mL of deionized water, heated to 60℃, ultrasonic treated at 60KHz for 6h, filtered, washed with deionized water for 3 times, dried in a 60℃ oven for 15min, to obtain a composite;

[0111] A2. 6g of cassava starch and 4mL of 20% mass fraction sodium silicate solution are mixed, stirred uniformly, placed at 25℃ for 1h, 0.7mL of dodecenyl succinic anhydride and 0.7mL of ethanol are added, stirred uniformly, sealed, placed at 25℃ for 3h, then heated to 75℃ and reacted for 3h, cooled to room temperature, taken out, washed with ethanol for 3 times, dried in a 70℃ oven for 10min, to obtain an amphoteric starch;

[0112] A3. 6g of the composite and 2.4g of the amphoteric starch are added to 55mL of ethanol, stirred uniformly, 10g of saponin and 11g of potassium perfluorobutyl sulfonate are added, stirred at 25℃ for 1.5h, heated to 70℃, and continue to stir until the solvent volatilizes, to obtain a fire extinguishing filler.

[0113] The modified zeolite is specifically prepared by the following steps:

[0114] B1. 1.3g of iron chloride hexahydrate is added to 30mL of 0.25mol / L hydrochloric acid, stirred uniformly, 6g of hydrochloric acid activated zeolite is added, ultrasonic treated at 40KHz for 10min, placed at 25℃ for 2h, filtered, washed with deionized water for 3 times, dried in an 80℃ oven for 10min, to obtain a zeolite loaded with iron ions;

[0115] B2. 8 g of tetraethyl orthosilicate was added to 65 mL of ethanol and 25 mL of deionized water, stirred uniformly, 45% ammonia water was added to adjust the pH to 9, stirred uniformly, 4 g of zeolite loaded with iron ions was added, stirred at 55℃ until gelling, filtered, washed with deionized water 3 times, dried in an oven at 70℃ for 10 min, to obtain the modified zeolite.

[0116] Comparative Example 3

[0117] A compounded lithium ion battery fire extinguishing agent, comprising the following mass parts of raw materials: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, modified zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinylpyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, water 50 parts;

[0118] A preparation method of a compounded lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0119] The expanded vermiculite, fire extinguishing filler, modified zeolite and water were mixed and stirred uniformly, ethylene glycol-butyl ether, polyvinylpyrrolidone, carboxymethyl cellulose, and sodium dodecyl sulfonate were added, and stirred at 700 r / min for 50 min to obtain the battery fire extinguishing agent.

[0120] The fire extinguishing filler was prepared by the following steps:

[0121] A1. 2 g of graphene oxide and 5.9 g of quaternary ammonium salt modified montmorillonite were added to 170 mL of deionized water, heated to 60℃, ultrasonically treated at 60 KHz for 6 h, filtered, washed with deionized water 3 times, and dried in an oven at 60℃ for 15 min to obtain a composite;

[0122] A2. 4 g of the composite was added to 120 mL of Tris-HCl buffer with a pH of 8.5, stirred at 25℃ and 2000 r / min for 20 min, 0.9 g of dopamine was added, stirred at 30℃ and 2000 r / min for 2 h, filtered, washed with deionized water 3 times, and dried in an oven at 70℃ for 10 min to obtain a modified composite;

[0123] A3. 6 g of the modified composite and 2.4 g of tapioca starch were added to 55 mL of ethanol, stirred uniformly, 10 g of saponin and 11 g of potassium perfluorobutyl sulfonate were added, stirred at 25℃ for 1.5 h, heated to 70℃, and continued to stir until the solvent evaporated to obtain the fire extinguishing filler.

[0124] The modified zeolite was prepared by the following steps:

[0125] B1. 1.3 g of ferric chloride hexahydrate was added to 30 mL of hydrochloric acid with a concentration of 0.25 mol / L, stirred uniformly, 6 g of hydrochloric acid activated zeolite was added, ultrasonic treatment was carried out at 40 KHz for 10 min, and then it was left to stand at 25℃ for 2 h, filtered, washed with deionized water for 3 times, and dried in an oven at 80℃ for 10 min to obtain zeolite loaded with iron ions;

[0126] B2. 8 g of tetraethyl orthosilicate was added to 65 mL of ethanol and 25 mL of deionized water, stirred uniformly, and then the pH was adjusted to 9 by adding 45% ammonia water, stirred uniformly, 4 g of zeolite loaded with iron ions was added, and then it was stirred at 55℃ until it became gel, filtered, washed with deionized water for 3 times, and dried in an oven at 70℃ for 10 min to obtain modified zeolite.

[0127] Comparative Example 4

[0128] A complex lithium ion battery fire extinguishing agent, comprising the following mass parts of raw materials: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, modified zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinylpyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, and water 50 parts;

[0129] A preparation method of a complex lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0130] The expanded vermiculite, fire extinguishing filler, modified zeolite and water were mixed and stirred uniformly, and then ethylene glycol-butyl ether, polyvinylpyrrolidone, carboxymethyl cellulose and sodium dodecyl sulfonate were added, and then it was stirred at 700 r / min for 50 min to obtain a battery fire extinguishing agent.

[0131] The fire extinguishing filler was prepared by the following steps:

[0132] A1. 2 g of graphene oxide and 5.9 g of quaternary ammonium salt modified montmorillonite were added to 170 mL of deionized water, and then the temperature was raised to 60℃, and ultrasonic treatment was carried out at 60 KHz for 6 h, and then it was filtered, washed with deionized water for 3 times, and dried in an oven at 60℃ for 15 min to obtain a composite;

[0133] A2. 4 g of the composite was added to 120 mL of Tris-HCl buffer with a pH of 8.5, and then it was stirred at 25℃ and 2000 r / min for 20 min, and then 0.9 g of dopamine was added, and then it was stirred at 30℃ and 2000 r / min for 2 h, and then it was filtered and washed with deionized water for 3 times, and then it was dried in an oven at 70℃ for 10 min to obtain a modified composite;

[0134] A3. 6 g of cassava starch and 4 mL of 20% by mass sodium silicate solution were mixed, stirred uniformly, and allowed to stand at 25°C for 1 h. Then, 0.7 mL of dodecenyl succinic anhydride and 0.7 mL of ethanol were added, stirred uniformly, sealed, allowed to stand at 25°C for 3 h, and then warmed to 75°C for reaction for 3 h. After cooling to room temperature, it was taken out, washed with ethanol 3 times, and dried in an oven at 70°C for 10 min to obtain amphoteric starch;

[0135] A4. 6 g of the modified composite and 2.4 g of the amphoteric starch were added to 55 mL of ethanol, stirred uniformly, and 21 g of saponin was added. Stirring was continued at 25°C for 1.5 h, and then the temperature was increased to 70°C until the solvent was volatilized to obtain fire extinguishing filler.

[0136] The modified zeolite was prepared by the following steps:

[0137] B1. 1.3 g of ferric chloride hexahydrate was added to 30 mL of 0.25 mol / L hydrochloric acid, stirred uniformly, and 6 g of hydrochloric acid-activated zeolite was added. Ultrasonic treatment was performed at 40 KHz for 10 min, and then allowed to stand at 25°C for 2 h. After filtration, it was washed with deionized water 3 times, and dried in an oven at 80°C for 10 min to obtain zeolite loaded with iron ions;

[0138] B2. 8 g of tetraethyl orthosilicate was added to 65 mL of ethanol and 25 mL of deionized water, stirred uniformly, and the pH was adjusted to 9 by adding 45% by mass ammonia water. After stirring uniformly, 4 g of the zeolite loaded with iron ions was added, and stirring was continued at 55°C until a gel was formed. After filtration, it was washed with deionized water 3 times, and dried in an oven at 70°C for 10 min to obtain modified zeolite.

[0139] Comparative Example 5

[0140] A compounded lithium ion battery fire extinguishing agent, comprising the following raw materials in mass parts: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, modified zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinylpyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, and water 50 parts;

[0141] A preparation method of a compounded lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0142] The expanded vermiculite, fire extinguishing filler, modified zeolite, and water were mixed and stirred uniformly, and the ethylene glycol-butyl ether, polyvinylpyrrolidone, carboxymethyl cellulose, and sodium dodecyl sulfonate were added. Stirring was continued at 700 r / min for 50 min to obtain the battery fire extinguishing agent.

[0143] The fire extinguishing filler was prepared by the following steps:

[0144] A1. 2 g of graphene oxide and 5.9 g of quaternary ammonium salt-modified montmorillonite were added to 170 mL of deionized water, heated to 60°C, and sonicated at 60 kHz for 6 h. The mixture was filtered, washed three times with deionized water, and dried in an oven at 60°C for 15 min to obtain a composite.

[0145] A2. 4 g of the complex was added to 120 mL of Tris-HCl buffer (pH 8.5) and stirred at 25°C and 2000 rpm for 20 min. 0.9 g of dopamine was added and stirred at 30°C and 2000 rpm for 2 h. The mixture was filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain the modified complex.

[0146] A3. 6 g of cassava starch was mixed with 4 mL of a 20% sodium silicate solution, stirred, and allowed to stand at 25°C for 1 hour. 0.7 mL of dodecenylsuccinic anhydride and 0.7 mL of ethanol were added, stirred, and sealed. The mixture was allowed to stand at 25°C for 3 hours, then heated to 75°C for 3 hours. The mixture was cooled to room temperature, removed, washed three times with ethanol, and dried in a 70°C oven for 10 minutes to obtain amphoteric starch.

[0147] A4. Add 6 g of the modified composite and 2.4 g of amphoteric starch to 55 mL of ethanol and stir evenly. Add 21 g of potassium perfluorobutanesulfonate and stir at 25°C for 1.5 h. Then, raise the temperature to 70°C and continue stirring until the solvent evaporates to obtain a fire-extinguishing filler.

[0148] The modified zeolite is specifically prepared by the following steps:

[0149] B1. 1.3 g of ferric chloride hexahydrate was added to 30 mL of 0.25 mol / L hydrochloric acid, stirred, and 6 g of hydrochloric acid-activated zeolite was added. The mixture was ultrasonically treated at 40 kHz for 10 min, allowed to stand at 25 ° C for 2 h, filtered, washed three times with deionized water, and dried in an 80 ° C oven for 10 min to obtain an iron ion-loaded zeolite;

[0150] B2. Add 8 g of ethyl orthosilicate to 65 mL of ethanol and 25 mL of deionized water, stir well, adjust the pH to 9 by adding 45% by mass ammonia, stir well, add 4 g of iron-loaded zeolite, and stir at 55°C until it forms a gel. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 min to obtain the modified zeolite.

[0151] Comparative Example 6

[0152] The compound type lithium ion battery fire extinguishing agent comprises the following raw materials in parts by mass: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, modified zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinyl pyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, and water 50 parts.

[0153] The preparation method of the compound type lithium ion battery fire extinguishing agent comprises the following preparation steps:

[0154] The expanded vermiculite, fire extinguishing filler, modified zeolite, and water are mixed and stirred uniformly, and the ethylene glycol-butyl ether, polyvinyl pyrrolidone, carboxymethyl cellulose, and sodium dodecyl sulfonate are added, and stirred at 700 r / min for 50 min to obtain the battery fire extinguishing agent.

[0155] The fire extinguishing filler is specifically prepared by the following steps:

[0156] A1. 2g of graphene oxide and 5.9g of quaternary ammonium salt modified montmorillonite are added to 170mL of deionized water, heated to 60℃, ultrasonically treated at 60KHz for 6h, filtered, washed with deionized water for 3 times, and dried in a 60℃ oven for 15min to obtain a composite;

[0157] A2. 4g of the composite is added to 120mL of Tris-HCl buffer with pH of 8.5, stirred at 25℃ and 2000r / min for 20min, 0.9g of dopamine is added, stirred at 30℃ and 2000r / min for 2h, filtered, washed with deionized water for 3 times, and dried in a 70℃ oven for 10min to obtain a modified composite;

[0158] A3. 6g of cassava starch and 4mL of 20% sodium silicate solution are mixed and stirred uniformly, placed at 25℃ for 1h, 0.7mL of dodecenyl succinic anhydride and 0.7mL of ethanol are added, stirred uniformly, sealed, placed at 25℃ for 3h, heated to 75℃ and reacted for 3h, cooled to room temperature, taken out, washed with ethanol for 3 times, and dried in a 70℃ oven for 10min to obtain an amphoteric starch;

[0159] A4. 6g of the modified composite and 2.4g of the amphoteric starch are added to 55mL of ethanol, stirred uniformly, 10g of saponin and 11g of potassium perfluorobutyl sulfonate are added, stirred at 25℃ for 1.5h, heated to 70℃, and continued to stir until the solvent volatilizes to obtain the fire extinguishing filler.

[0160] The modified zeolite is specifically prepared by the following steps:

[0161] 8g tetraethyl orthosilicate was added into 65mL ethanol and 25mL deionized water, stirred uniformly, 45% mass fraction of ammonia water was added to adjust pH to 9, stirred uniformly, 4g hydrochloric acid activated zeolite was added, stirred at 55℃ until gelled, filtered, washed with deionized water for 3 times, dried in 70℃ oven for 10min, to obtain modified zeolite.

[0162] Comparative example 7

[0163] A compound type lithium ion battery fire extinguishing agent, comprising the following mass parts of raw materials: expanded vermiculite 35 parts, fire extinguishing filler 7 parts, iron ion loaded zeolite 8 parts, ethylene glycol-butyl ether 1 part, polyvinylpyrrolidone 2 parts, carboxymethyl cellulose 2 parts, sodium dodecyl sulfonate 3 parts, water 50 parts;

[0164] A preparation method of a compound type lithium ion battery fire extinguishing agent, comprising the following preparation steps:

[0165] The expanded vermiculite, fire extinguishing filler, iron ion loaded zeolite and water were mixed and stirred uniformly, ethylene glycol-butyl ether, polyvinylpyrrolidone, carboxymethyl cellulose, and sodium dodecyl sulfonate were added, stirred at 700r / min for 50min, to obtain a battery fire extinguishing agent.

[0166] The fire extinguishing filler was prepared by the following steps:

[0167] A1. 2g graphene oxide and 5.9g quaternary ammonium salt modified montmorillonite were added into 170mL deionized water, heated to 60℃, ultrasonic treated at 60KHz for 6h, filtered, washed with deionized water for 3 times, dried in 60℃ oven for 15min, to obtain a composite;

[0168] A2. 4g composite was added into 120mL Tris-HCl buffer with pH of 8.5, stirred at 25℃, 2000r / min for 20min, 0.9g dopamine was added, stirred at 30℃, 2000r / min for 2h, after filtration, washed with deionized water for 3 times, dried in 70℃ oven for 10min, to obtain a modified composite;

[0169] A3. 6g tapioca starch and 4mL 20% mass fraction of sodium silicate solution were mixed, stirred uniformly, placed at 25℃ for 1h, 0.7mL dodecenyl succinic anhydride and 0.7mL ethanol were added, stirred uniformly, sealed, placed at 25℃ for 3h, then heated to 75℃ for 3h, cooled to room temperature, taken out, washed with ethanol for 3 times, dried in 70℃ oven for 10min, to obtain an amphoteric starch;

[0170] A4. 6 g of the modified composite and 2.4 g of amphoteric starch were added to 55 mL of ethanol, stirred until uniform, 10 g of saponin and 11 g of potassium perfluorobutyl sulfonate were added, stirred at 25°C for 1.5 h, the temperature was raised to 70°C, and the stirring was continued until the solvent evaporated, to obtain the fire extinguishing filler.

[0171] The zeolite loaded with iron ions was prepared by the following steps:

[0172] 1.3 g of iron chloride hexahydrate was added to 30 mL of hydrochloric acid with a concentration of 0.25 mol / L, stirred until uniform, 6 g of hydrochloric acid activated zeolite was added, ultrasonic treatment was carried out at 40 KHz for 10 min, and then the mixture was left to stand at 25°C for 2 h, filtered, washed with deionized water for 3 times, and dried in an oven at 80°C for 10 min, to obtain the zeolite loaded with iron ions.

[0173] The battery fire extinguishing agents prepared in Examples 1-3 and Comparative Examples 1-7 were subjected to performance detection.

[0174] The battery fire extinguishing agent prepared above was packaged in a fire extinguishing container to form a storage pressure type fire extinguisher, which was filled with 1 kg, the nozzle pressure was set to 0.5 MPa, the flow rate was controlled to be 5 L / min, and the nozzle hole diameter was 3 mm. The fire extinguisher filled with the battery fire extinguishing agent prepared above was subjected to the following fire extinguishing simulation experiment.

[0175] Twelve test lithium batteries were connected in parallel and placed on a heating plate, the power of the heating plate was 1 kW, the temperature was set to 600°C, the size was 210 mm x 170 mm x 15 mm, the batteries were charged to 100%, and then the power was turned off. The heating plate was uniformly heated at a rate of 20°C / min. When the batteries started to heat, smoke, or even appeared as a flame, a lithium ion battery fire was triggered.

[0176] Fire extinguishing performance test: after the battery appeared as a flame, the burning state was maintained for 10 s, the fire extinguisher filled with the battery fire extinguishing agent prepared above was used, and the extinguishing agent was continuously sprayed at a distance of 1.5 m from the fire source until the flame was completely extinguished. The extinguishing time was recorded. Whether the battery appeared as a flame again after 0.5 h, 1 h, and 1.5 h of extinguishing was observed.

[0177] The test results are shown in Table 1 below.

[0178] Table 1 Performance detection of the battery fire extinguishing agents prepared in Examples 1-3 and Comparative Examples 1-5

[0179]

[0180] As can be seen from the data in Table 1, the battery fire extinguishing agents prepared in Examples 1-3 have high fire extinguishing performance and are not prone to reignition.

[0181] The fire extinguishing filler prepared in Step A of Comparative Example 1 without ultrasonic treatment was added to the battery fire extinguishing agent, and the fire extinguishing performance was reduced, which proved that the ultrasonic treatment of graphene oxide and montmorillonite made the graphene oxide intercalated into the interlayer of montmorillonite to form a layered material, which could form a barrier layer to prevent the transmission of oxygen and heat, block the combustion of lithium ion batteries, and achieve the purpose of fire extinguishing. The graphene oxide acted as a support structure for the montmorillonite, improving the mechanical strength of the expanded montmorillonite, preventing the barrier layer of the expanded montmorillonite from breaking down at high temperatures, and affecting the fire extinguishing efficiency.

[0182] In Comparative Example 2, the modified composite was replaced by the composite to prepare the fire extinguishing filler, which was added to the battery fire extinguishing agent, and the fire extinguishing performance was reduced, which proved that dopamine could self-polymerize on the surface of the composite to form polydopamine, forming a modified composite that was beneficial to the formation of a fire extinguishing layer in the lithium ion battery. The presence of polydopamine in the fire extinguishing filler could form a dense carbon layer, allowing the distribution of combustible molecules between the carbon layers to further isolate oxygen and improve the fire extinguishing efficiency.

[0183] In Comparative Example 3, the amphoteric starch was replaced by cassava starch to prepare the fire extinguishing filler, which was added to the battery fire extinguishing agent, and the fire extinguishing performance was reduced, which proved that the modified composite coated with amphiphilic starch and containing hydrophobic carbon chains could repel water molecules, capture combustible molecules, and form microcapsule structures, interrupting the chain reaction of combustion free radicals. The hydrophilic groups could be adsorbed onto the water film covering the surface of the battery, allowing the graphene oxide intercalated montmorillonite composite and the microcapsule structure to form a dense barrier layer on the surface of the battery, preventing the transmission of oxygen and heat, and achieving the purpose of fire extinguishing.

[0184] In Comparative Example 4, only saponin was used to prepare the fire extinguishing filler, and in Comparative Example 5, only potassium perfluorobutyl sulfonate was used to prepare the fire extinguishing filler, which was added to the battery fire extinguishing agent, and the fire extinguishing performance was reduced, which proved that saponin and potassium perfluorobutyl sulfonate allowed the fire extinguishing agent to form a uniform water film on the surface of the battery, blocking oxygen and not wetting the battery, which had good fire extinguishing effect. The fire extinguishing filler was also beneficial to the formation of a dense barrier layer on the surface of the battery, preventing the transmission of oxygen and heat.

[0185] In Comparative Example 6, the zeolite loaded with iron ions was replaced by hydrochloric acid activated zeolite to prepare the modified zeolite, which was added to the battery fire extinguishing agent, and the fire extinguishing performance was reduced, which proved that the hydrochloric acid activated zeolite could adsorb a large number of combustion free radicals, and the loaded iron ions could react with active free radicals in the flame, inhibiting the spread of the flame through chemical action, and better completing the fire extinguishing.

[0186] In Comparative Example 7, the modified zeolite was replaced by zeolite loaded with iron ions, which was added to the battery fire extinguishing agent, and the fire extinguishing performance was reduced, which proved that the zeolite loaded with iron ions was embedded in the silicone gel, and during the fire extinguishing process, the silicone dehydrated to form high-temperature-resistant silicon dioxide distributed on the surface of the zeolite, avoiding the collapse of the zeolite framework due to thermal shock and thermal stress, and affecting the fire extinguishing performance.

[0187] In the description, references to "one embodiment," "an example," "certain examples" etc. mean that the particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of an item in various examples, as is in the description, are not necessarily referring to the same embodiment or example. Moreover, descriptions of well-known structures, materials or components can be omitted so as to avoid obscuring the application. The same reference numerals in different drawings represent the same element.

[0188] The above description is intended to be illustrative and not restrictive. Many other modifications utilizing this application will occur to those skilled in the art, which modifications will be within the scope of the application as defined by the appended claims.

Claims

1. A composite lithium-ion battery fire extinguishing agent, characterized in that: The invention comprises the following raw materials in parts by weight: 30-35 parts of vermiculite, 5-7 parts of fire extinguishing filler, 6-8 parts of modified zeolite, 0.5-1 parts of stabilizer, 1.5-2 parts of dispersant, 1-2 parts of thickener, 1-3 parts of foaming agent and 40-50 parts of water; The fire extinguishing filler is made of graphene oxide intercalated montmorillonite, which is surface-modified with dopamine and then mixed with amphoteric starch, saponin and potassium perfluorobutanesulfonate; The modified zeolite is obtained by mixing hydrochloric acid activated zeolite with ferric chloride hexahydrate and then mixing with organic silicon.

2. A composite lithium-ion battery fire extinguishing agent according to claim 1, characterized in that: The fire extinguishing filler is specifically prepared by the following steps: A1. Graphene oxide and montmorillonite were added to deionized water, heated to 50-60°C, ultrasonically treated at 40-60 kHz for 5-6 hours, filtered, washed, and dried to obtain a composite; A2. The complex was added to Tris-HCl buffer, stirred evenly, dopamine was added, stirring was continued, filtered, washed, and dried to obtain a modified complex; A3. Mix the starch and sodium silicate solution, stir evenly, let it stand, add dodecenylsuccinic anhydride and ethanol, stir evenly, seal, continue to stand, heat to 65-75 ° C, react for 1-3h, cool to room temperature, remove, wash, and dry to obtain amphoteric starch; A4. Add the modified complex and amphoteric starch to ethanol and stir evenly. Then add saponin and potassium perfluorobutanesulfonate. Stir at room temperature, then raise the temperature and continue stirring until the solvent evaporates to obtain a fire-extinguishing filler.

3. A composite lithium-ion battery fire extinguishing agent according to claim 2, characterized in that: In step A1, the ratio of graphene oxide, montmorillonite and deionized water is (1-2) g: (5.5-5.9) g: (130-170) mL.

4. A composite lithium-ion battery fire extinguishing agent according to claim 2, characterized in that: In step A2, the ratio of the complex, Tris-HCl buffer and dopamine is (3-4) g: (80-120) mL: (0.7-0.9) g.

5. A composite lithium-ion battery fire extinguishing agent according to claim 2, characterized in that: In step A3, the ratio of starch, sodium silicate solution, dodecenylsuccinic anhydride and ethanol is (4-6) g: (2-4) mL: (0.5-0.7) mL: (0.5-0.7) mL.

6. A composite lithium-ion battery fire extinguishing agent according to claim 2, characterized in that: In step A4, the ratio of the modified complex, amphoteric starch, ethanol, saponin and potassium perfluorobutanesulfonate is (5-6) g: (2-2.4) g: (45-55) mL: (8-10) g: (9-11) g.

7. The composite lithium-ion battery fire extinguishing agent according to claim 1, characterized in that: The modified zeolite is specifically prepared by the following steps: B1. Ferric chloride hexahydrate was added to hydrochloric acid, stirred, hydrochloric acid was added to activate the zeolite, ultrasonicated, allowed to stand, filtered, washed, and dried to obtain a zeolite loaded with iron ions; B2. Add organosilicon to ethanol and deionized water, stir evenly, add ammonia to adjust the pH to 8-9, stir evenly, add iron ion-loaded zeolite, stir at 45-55°C until it becomes a gel, filter, wash, and dry to obtain modified zeolite.

8. A composite lithium-ion battery fire extinguishing agent according to claim 7, characterized in that: In step B1, the ratio of the amount of ferric chloride hexahydrate, hydrochloric acid and hydrochloric acid-activated zeolite is (1.2-1.3) g: (20-30) mL: (4-6) g.

9. The composite lithium-ion battery fire extinguishing agent according to claim 7, characterized in that: In step B2, the ratio of the amount of the organosilicon, ethanol, deionized water and iron ion-loaded zeolite is (7-8) g: (55-65) mL: (15-25) mL: (3-4) g.

10. A method for preparing the composite lithium-ion battery fire extinguishing agent according to any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: Vermiculite, fire extinguishing filler, modified zeolite and water are mixed and stirred evenly, a stabilizer, a dispersant, a thickener and a foaming agent are added, and the mixture is stirred at 500-700 r / min for 30-50 minutes to obtain a battery fire extinguishing agent.

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