阅读说明：本技术 一种适用于扑灭锂离子电池火灾的有机/无机杂化核壳结构灭火剂及其制备方法 (Organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire and preparation method thereof ) 是由 张和平 付阳阳 张忠心 赵军超 薛峰 闫明远 于 2021-06-10 设计创作，主要内容包括：本发明提供了一种适用于扑灭锂离子电池火灾的有机/无机杂化核壳结构灭火剂及其制备方法,其制备方法包括有机水凝胶的合成与有机/无机杂化核壳结构灭火剂的制备。本发明利用自由基聚合反应制备有机水凝胶,将有机水凝胶与疏水型气相二氧化硅在高速搅拌下相互分散,使气相二氧化硅包裹在水凝胶微粒表明形成具有核壳结构的灭火剂。本发明提供的灭火材料制备工艺简单,操作简便,适合大批量生产并推广使用。(The invention provides an organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire and a preparation method thereof. The invention utilizes free radical polymerization to prepare organic hydrogel, and mutually disperses the organic hydrogel and hydrophobic fumed silica under high-speed stirring, so that the fumed silica is wrapped on the surface of hydrogel particles to form the fire extinguishing agent with a core-shell structure. The fire extinguishing material provided by the invention is simple in preparation process, simple and convenient to operate, and suitable for mass production and popularization and use.)

1. An organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire is characterized by comprising the following raw materials in parts by weight:

700 portions of hydrophobic silica 400,

20-50 parts of acrylic acid,

10-35 parts of sodium bicarbonate,

10-80 parts of acrylamide,

3-5 parts of methyl methacrylate,

2-5 parts of ethyl methacrylate,

2-5 parts of butyl methacrylate,

0-5 parts of ethyl acrylate,

0-20 parts of hydroxyethyl methacrylate,

20-60 parts of N-isopropyl acrylamide,

0-30 parts of N- (2-hydroxyethyl) acrylamide,

1 part of N, N' -methylene bisacrylamide,

1 part of potassium persulfate,

The total weight portion is 5000 portions,

The balance being deionized water.

2. The preparation method of the organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which is disclosed by claim 1, is characterized by comprising the following steps:

(1) adding acrylic acid and sodium bicarbonate into deionized water, and magnetically stirring at room temperature for 10-30min to obtain a mixed solution;

(2) adding acrylamide, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, hydroxyethyl methacrylate, N-isopropyl acrylamide, N- (2-hydroxyethyl) acrylamide and N, N' -methylene bisacrylamide into the mixed solution, sealing, discharging air, introducing nitrogen, adding a potassium persulfate aqueous solution into the mixed solution by using an injector, and stirring for 20-36 hours at room temperature to obtain a cross-linked polymer solution;

(3) placing the crosslinked polymer solution in a glass bottle with a plug, and standing for 4h at 85 ℃ to obtain crosslinked polymer hydrogel;

(4) crushing the crosslinked polymer hydrogel, and adding deionized water to make the crosslinked polymer hydrogel absorb water and swell;

(5) adding the hydrophobic silicon dioxide and the swelled hydrogel into a high-speed stirrer, and stirring at the rotating speed of 2000-2400r/min for 6-12s to obtain the organic/inorganic hybrid core-shell structure fire extinguishing agent.

3. The method according to claim 2, wherein the acrylamide, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, hydroxyethyl methacrylate, N-isopropylacrylamide, N- (2-hydroxyethyl) acrylamide, acrylic acid, sodium bicarbonate, N' -methylenebisacrylamide, potassium persulfate and deionized water are added in an amount of 10 to 80 parts by weight of acrylamide, 3 to 5 parts by weight of methyl methacrylate, 2 to 5 parts by weight of ethyl methacrylate, 2 to 5 parts by weight of butyl methacrylate, 0 to 5 parts by weight of ethyl acrylate, 0 to 20 parts by weight of hydroxyethyl methacrylate, 20 to 60 parts by weight of N-isopropylacrylamide, 0 to 30 parts by weight of N- (2-hydroxyethyl) acrylamide in step (1) (2), 20-50 parts of acrylic acid, 10-35 parts of sodium bicarbonate, 1 part of N, N' -methylene bisacrylamide and 1 part of potassium persulfate, wherein the total weight is 5000, and the balance is deionized water.

4. The method according to claim 2, wherein the mass ratio of the hydrogel in the step (4) to the additionally added deionized water is 1:4-12, and the final hydrogel comprises 5-30 parts by weight of the crosslinked polymer and 970 parts by weight of water, and the total weight is 1000 parts by weight.

5. The method according to claim 2, wherein the weight parts of the hydrophobic silica and the swollen hydrogel in the step (5) are 2 to 15 parts of silica and 85 to 98 parts of hydrogel, and the total weight part is 100.

6. The method of claim 2, wherein the fire extinguishing agent end product is prepared and then filled in a general-purpose portable fire extinguishing cylinder, and the cylinder is filled with 0.5 to 2.0MPa of nitrogen gas and sealed after filling.

Technical Field

The invention belongs to the technical field of fire materials, and particularly relates to a preparation method of an organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing a lithium ion battery fire.

Background

In recent years, lithium ion batteries have been widely used in the fields of portable electronic devices, new energy automobiles, electrochemical energy storage power stations, aviation airplanes and the like due to their advantages of high energy density, small size, long service life, good cycle performance and the like. The lithium ion battery can generate thermal runaway (self-heating exothermic reaction) under the conditions of thermal abuse, electrical abuse, mechanical abuse and the like, and the thermal runaway is very easy to cause fire or explosion. Lithium ion battery fire accidents frequently occur, and great loss is caused to life and property of people. Therefore, the research on the lithium ion battery fire extinguishing technology has important significance for guaranteeing the use safety of the lithium ion battery and promoting the healthy and rapid development of national electrochemical energy storage power stations and new energy automobile industries.

Unlike traditional solid combustible materials, the lithium ion battery is a closed system, and has three factors of ignition or explosion under the abuse of heat, machinery or electricity, electrolyte, a diaphragm, a plastic shell and the like are all combustible materials, positive and negative active materials are thermally decomposed to provide oxygen, internal materials are subjected to a series of uncontrollable exothermic reactions with each other, a large amount of combustible gases, electrolyte, solid residues and other combustible materials are released, the limit of combustion is reached, and then a fire disaster occurs, wherein the fire disaster is a comprehensive fire disaster of gas fire (C type fire), liquid fire (B type fire) and solid fire (A type fire), and meanwhile, the internal pressure of the lithium ion battery is sharply increased by a large amount of generated gas, and when the internal pressure exceeds the bearing pressure of a shell, the lithium ion battery can explode.

The lithium ion battery fire has the characteristics of high temperature, easy explosion, multiple jet fire injection, high toxicity and the like, and the fire extinguishing agent is required to have the following properties: 1) the cooling capacity is very strong to inhibit the thermal runaway of the lithium ion battery from continuously occurring among the modules; 2) can overcome the impact of three-dimensional jet fire and lead the fire extinguishing agent to reach the root of combustion.

Fire extinguishing agents are substances that are effective in destroying combustion conditions and terminating combustion. When a lithium titanate ion battery is in a fire disaster, the loss of life and property is greatly reduced by selecting and correctly using a proper fire extinguishing agent. At present, the fire extinguishing agent is mainly divided into three types of solid, liquid and gas fire extinguishing agents.

WhereinSolid fire extinguishing agent: the superfine dry powder fire extinguishing agent is divided into BC dry powder and ABC dry powder. The BC dry powder is mostly NaHCO₃As a main raw material, can extinguish B, C, E, F type fires. The ABC dry powder fire extinguishing agent mainly comprises ammonium phosphate salt and can extinguish A, B, C, F-class fire. The fire extinguishing mechanism of the superfine dry powder extinguishing agent is as follows: primarily chemical inhibition, followed by asphyxiation. Combustion is a chain reaction process. Combustible molecules generate key free radicals OH, H and O for maintaining combustion chain reaction at high temperature, and rely on the propagation reaction of the high-activity free radicals to maintain the continuous combustion. The superfine dry powder extinguishing agent can consume the high-activity free radicals, when the particles are contacted with the free radicals generated in the flame, the free radicals are instantly adsorbed on the surfaces of the particles, the high-activity free radicals are consumed, the combustion chain reaction is stopped, and the flame is extinguished. Besides, the powder particles melted at high temperature form a glassy covering layer to isolate air and combustion substances, and have a suffocation effect; the powder particles have large specific surface area, are easy to absorb heat and have a certain cooling effect. The superfine dry powder extinguishing agent has the characteristics of high extinguishing efficiency, high speed, no toxicity to environment, people and livestock and the like, but has obvious defects, and the re-combustion of the lithium ion battery fire cannot be inhibited due to poor cooling effect.

The aerosol fire extinguishing agent is micron level dry powder particle capable of being suspended in air and consists of oxidant, reductant and adhesive and produces fire extinguishing medium through combustion reaction. The aerosol fire extinguishing mechanism mainly comprises the combined action of chemical inhibition and physical temperature reduction. Firstly, in the aspect of chemical inhibition, the surface energy of aerosol particles is very high, and the aerosol particles can adsorb active groups OH, H and O in combustion, so that stable molecules are combined among free radicals, the chain reaction of combustion is interrupted, and instantaneous fire extinguishing is generated. Meanwhile, under the action of high temperature, cations decomposed from aerosol particles undergo multiple chain reactions with H and OH, H and O are consumed and inhibited to achieve the fire extinguishing effect. In the aspect of physical temperature reduction, the micron-sized fire extinguishing agent has large specific surface area, is very easy to absorb flame heat, and can absorb a large amount of heat by melting or gasifying particles when the absorbed heat is enough, so that the temperature of a combustion object can be effectively reduced. The aerosol fire extinguishing agent has the advantages of high fire extinguishing speed, high efficiency, low price, good space submergence, low ozone consumption potential value and greenhouse effect potential value, normal-pressure storage and the like. It is suitable for A, B, C, E fire. The aerosol is an unclean fire extinguishing agent, has certain residue after fire extinguishing, and because the aerosol is generated in a combustion mode, the fire extinguishing agent has the danger of fire and explosion, so the aerosol is not suitable for extinguishing the fire of the lithium ion battery.

Gas fire extinguishing agent: the perfluorohexanone fire extinguishing agent is liquid at normal temperature and has a boiling point of 48-49 ℃, because the evaporation heat of the perfluorohexanone fire extinguishing agent is only 1/25 times that of water, and the vapor pressure of the perfluorohexanone fire extinguishing agent is 25 times that of the water, so that the perfluorohexanone fire extinguishing agent is easy to vaporize and exists in a gas state, and the fire extinguishing effect is achieved mainly by heat absorption. Its Ozone Depletion Potential (ODP): 0, Global Warming Potential (GWP): atmospheric survival life (years): 0.014(5 days), is an environment-friendly fire extinguishing agent. The perfluorohexanone fire extinguishing agent has the comprehensive advantages of high fire extinguishing efficiency, environmental protection, cleanness, safe use, good insulating property and the like, can be applied to fire extinguishing systems in all areas or local areas, is particularly suitable for places where people work but are closed, but the fire extinguishing agent is heated and decomposed to generate a large amount of HF, and meanwhile, the pyrolysis product of the fire extinguishing agent has a certain corrosion effect on equipment.

The fire extinguishing mechanism of the heptafluoropropane fire extinguishing agent is mainly chemical inhibition fire extinguishing, and then physical temperature reduction and suffocation fire extinguishing. The heptafluoropropane fire extinguishing agent is thermally decomposed in flame to generate CF₃、·CF₂、·CF₃The fluorine-containing radicals such as CFO and CFO act on active groups OH, H and O in combustion to interrupt the chain reaction of combustion. The heptafluoropropane stored in the liquid state releases gasification and absorption heat, has a certain cooling effect, and meanwhile, the density of the heptafluoropropane is 6 times that of air, and can cover the surface of a combustion object to isolate the air, so that the combustion is suffocated. The fire extinguishing agent can extinguish A, B, C, E fire, and has the advantages of quick fire extinguishing, small dosage, easy storage, no residue after fire extinguishing, no breakdown of electronic components, no ozone loss and the like. But the heptafluoropropane has the greenhouse effect (the GWP is 3200), the atmosphere survives for 31-42 years, and a large amount of toxic gas HF is generated by decomposition during fire extinguishing.

Foam extinguishants are fire extinguishing agents that are compatible with water and can produce fire extinguishing foam by chemical reaction or mechanical means. The types are: air foam extinguishing agent, fluoroprotein foam extinguishing agent, aqueous film-forming foam extinguishing agent, anti-solubility foam extinguishing agent and the like. The fire extinguishing mechanism of foam extinguishers is mainly to extinguish fire by using the cooling effect of water and the choking effect of foam isolated from air. The foam covering layer formed on the surface of the comburent by the foam can isolate the comburent from air, block the heat radiation of flame to the comburent, reduce the decomposition and evaporation of the comburent, and make the combustible gas difficult to enter the combustion area, thereby having the function of suffocation. The water separated out from the foam can absorb heat to evaporate and reduce the temperature of the combustion area, and the water vapor can also dilute the oxygen in the combustion area to have cooling and suffocation effects. Because the foam impact quantity is small, the combustion of the lithium ion battery is in a jet shape, and the foam extinguishing agent is difficult to penetrate through a combustion area to further cover the surface of the lithium ion battery, the foam extinguishing agent is not suitable for extinguishing the fire of the lithium ion battery.

The water mist fire extinguishing agent is characterized in that 99% of water mist on a plane 1m away from a nozzle under the minimum design working pressure has the diameter smaller than 1000 um. The fire extinguishing mechanism of the water mist is similar to that of water, mainly a cooling effect and secondly a suffocation effect, but after ordinary water is thinned, the specific surface area of the ordinary water is increased compared with that of ordinary water drops, the contact area of the water and flames is increased, the water can be completely evaporated in a fire scene, and the heat absorption efficiency is improved. The water mist blocks heat radiation through wetting and emulsifying effects on the combustible, reduces heat feedback on the combustible, reduces decomposition of solid combustible and vaporization and evaporation of liquid combustible, and accordingly reduces the content of combustible gas in a combustion area. The chemical reaction rate and flame propagation rate of the burning substances are greatly reduced. The water mist has the advantages of no environmental pollution, no ozone loss, no greenhouse effect, quick fire extinguishing, low water consumption and small destructiveness on fire-catching objects, can extinguish A, B, C and F-class fires, is widely concerned by extensive researchers at home and abroad, and becomes one of the substitutes of Halon fire extinguishing agents. However, the fine water mist has small particles and is difficult to penetrate through smoke and plume buoyancy to reach the surface of the lithium ion battery for cooling, and in addition, the fine water mist droplets do not have a covering and fire extinguishing effect and cannot effectively prevent pyrolysis gas of the lithium ion battery from contacting air, so the fine water mist also needs to be continuously sprayed in a large amount to have a good re-combustion resisting effect; in addition, the water mist fire extinguishing system has complex equipment, high manufacturing cost and strict technical requirements, so the application of the water mist fire extinguishing system in the field of lithium ion battery fire extinguishing is limited to a certain extent.

The water fire-fighting mechanism relies primarily on a cooling effect followed by a choking effect. The heat of vaporization of water is 40.8 kJ. mol^-1Each kilogram of water absorbs 2260kJ of heat, and after the water is evaporated, a large amount of heat is absorbed, so that the surface temperature of a combustion object is reduced, and the flame is extinguished. In addition, the volume of each kilogram of the gasified water expands by about 1700 times, and a large amount of oxygen in a combustion area is diluted, so that combustion of combustion substances is stopped due to oxygen deficiency, and the aim of extinguishing fire by suffocation is fulfilled. The water is cheap and easy to obtain, has wide sources and no pollution to the environment, and becomes the most commonly used fire extinguishing agent for fighting the fire of the lithium ion battery. At present, the fire extinguishing method agreed by scholars at home and abroad is that a large amount of water is continuously sprayed to effectively extinguish the lithium ion battery fire, but the water has high fluidity and is difficult to stay on the surface of the lithium ion battery, the water actually playing a cooling role is less than 20%, the water containing impurities has conductivity and is easy to cause short circuit outside the lithium ion battery, and in addition, the water can react with the electrolyte components of the lithium ion battery to generate a large amount of toxic gases of CO and HF. Therefore, the key technical problem that the fire extinguishing efficiency of the lithium ion battery needs to be overcome when the lithium ion battery is put out of fire is that the loss of water is reduced and the fire extinguishing efficiency of the water is greatly improved.

Disclosure of Invention

In view of the above, the invention provides an organic/inorganic hybrid core-shell structure fire extinguishing agent for extinguishing lithium ion battery fire and a preparation method thereof. The organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing fire of the lithium ion battery, which is prepared by the invention, is formed by combining polyacrylamide cross-linked polymer organic hydrogel and hydrophobic silicon dioxide, a large amount of hydrogel membranes are formed on the surface of the lithium ion battery after the fire extinguishing agent is sprayed into fire, water in the gel is evaporated to consume a large amount of heat (the water utilization rate reaches 90%), fire extinguishing components such as sodium bicarbonate and the like are thermally decomposed to absorb heat and capture free radicals, so that the fire extinguishing agent has the effects of quickly extinguishing fire, inhibiting re-combustion and preventing thermal runaway from spreading among the lithium ion batteries; meanwhile, the residual silicon dioxide covers the surface of the lithium ion battery and is choked to extinguish the fire. Because the water of the organic/inorganic hybrid fire extinguishing agent with the core-shell structure is not contacted with the lithium ion battery all the time, the possibility of short circuit of the lithium ion battery caused by the water is avoided, and secondary disasters are avoided. The fire extinguishing material provided by the invention has the advantages of simple preparation process, simplicity and convenience in operation, high efficiency of the fire extinguishing agent, environmental friendliness, re-combustion resistance and suitability for mass production and popularization and use.

The invention provides an organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which comprises the following raw materials in parts by weight:

700 portions of hydrophobic silica 400,

20-50 parts of acrylic acid,

10-35 parts of sodium bicarbonate,

10-80 parts of acrylamide,

3-5 parts of methyl methacrylate,

2-5 parts of ethyl methacrylate,

2-5 parts of butyl methacrylate,

0-5 parts of ethyl acrylate,

0-20 parts of hydroxyethyl methacrylate,

20-60 parts of N-isopropyl acrylamide,

0-30 parts of N- (2-hydroxyethyl) acrylamide,

1 part of N, N' -methylene bisacrylamide,

1 part of potassium persulfate,

The total weight portion is 5000 portions,

The balance being deionized water.

The invention also provides a preparation method of the organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which comprises the following steps:

(1) adding acrylic acid and sodium bicarbonate into deionized water, and magnetically stirring at room temperature for 10-30min to obtain a mixed solution;

(2) adding acrylamide, hydroxyethyl methacrylate, N-isopropyl acrylamide, N- (2-hydroxyethyl) acrylamide, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate and N, N' -methylene bisacrylamide into the mixed solution, sealing, discharging air, introducing nitrogen, adding a potassium persulfate aqueous solution into the mixed solution by using an injector, and stirring for 20-36 hours at room temperature to obtain a cross-linked polymer solution;

(3) placing the crosslinked polymer solution in a glass bottle with a plug, and standing for 12h at 85 ℃ to obtain crosslinked polymer hydrogel;

(4) crushing the crosslinked polymer hydrogel, and adding deionized water to make the crosslinked polymer hydrogel absorb water and swell;

(5) adding the hydrophobic silicon dioxide and the swelled hydrogel into a high-speed stirrer, and stirring at the rotating speed of 2000-2400r/min for 6-12s to obtain the organic/inorganic hybrid core-shell structure fire extinguishing agent.

The weight parts of the acrylamide, the methyl methacrylate, the ethyl methacrylate, the butyl methacrylate, the ethyl acrylate, the hydroxyethyl methacrylate, the N-isopropylacrylamide, the N- (2-hydroxyethyl) acrylamide, the acrylic acid, the sodium bicarbonate, the N, N' -methylenebisacrylamide, the potassium persulfate and the deionized water in the step (1) and (2) are 10 to 80 parts of acrylamide, 3 to 5 parts of methyl methacrylate, 2 to 5 parts of ethyl methacrylate, 2 to 5 parts of butyl methacrylate, 0 to 5 parts of ethyl acrylate, 0 to 20 parts of hydroxyethyl methacrylate, 20 to 60 parts of N-isopropylacrylamide, 20 to 60 parts of N- (2-hydroxyethyl) acrylamide, 20 to 50 parts of acrylic acid, sodium hydrogen sulfite, sodium hydrogen carbonate and deionized water, 10-35 parts of sodium bicarbonate, 1 part of N, N' -methylene bisacrylamide and 1 part of potassium persulfate, wherein the total weight part is 1000, and the balance is deionized water.

The mass ratio of the hydrogel in the step (4) to the additionally added deionized water is 1:4-12, and the weight parts of the polymer and the water in the finally formed hydrogel are 5-30 parts of the crosslinked polymer and 970-995 parts of water, and the total weight part is 1000.

The weight parts of the hydrophobic silicon dioxide and the swelled hydrogel in the step (5) are 2-15 parts of silicon dioxide and 85-98 parts of hydrogel, and the total weight part is 100.

After the final product of the fire extinguishing agent is prepared, the fire extinguishing agent is filled into a general portable fire extinguishing steel cylinder, nitrogen gas with the pressure of 0.5-2.0MPa is filled, and the steel cylinder is sealed after filling.

The invention has the beneficial effects that:

the invention utilizes free radical polymerization to prepare organic hydrogel, and mutually disperses the organic hydrogel and hydrophobic fumed silica under high-speed stirring, so that the fumed silica is wrapped on the surface of hydrogel particles to form the fire extinguishing agent with a core-shell structure. After the fire extinguishing agent with the organic/inorganic hybrid core-shell structure is sprayed, a large amount of hydrogel films can be formed on the surface of a lithium ion battery, on one hand, moisture in the gel is heated, evaporated, absorbed and continuously cooled (the water utilization rate reaches 90%), on the other hand, fire extinguishing components such as sodium bicarbonate and the like are thermally decomposed, absorbed and free radicals are captured, silicon dioxide on the surface of the fire extinguishing agent belongs to inert substances, oxygen can be isolated by attaching to the surface of the lithium ion battery, the contact between pyrolysis release products of the lithium ion battery and a combustion improver is prevented, and the fire is extinguished, so that the cooling, chemical inhibition, suffocation and isolation effects are fully exerted; secondly, the fire extinguishing agent has good spatial dispersibility and cooling property, is beneficial to quickly extinguishing fire and simultaneously preventing the secondary combustion of the lithium ion battery fire; the fire extinguishing agent has good fluidity, stability and anti-caking performance, and is beneficial to spraying, storing and transporting; the fire extinguisher is non-toxic and harmless, has no secondary pollution, is insulating, is easy to clean after fire extinguishment, and is beneficial to environmental protection and fire extinguishment. The fire extinguishing material provided by the invention is simple in preparation process, simple and convenient to operate, and suitable for mass production and popularization and use.

Drawings

FIG. 1 is a photograph showing the fire extinguishing agent prepared in example 1 after the test of water repellency by dropping distilled water.

Fig. 2 is a picture of the water drop after the fire extinguishing agent prepared in example 1 is tested for water repellency and is tilted.

FIG. 3 is a thermogravimetric plot of the fire extinguishing agent prepared in example 2.

FIG. 4 is a particle size distribution diagram of the fire extinguishing agent prepared in example 3.

FIG. 5 is a microstructure view of the fire extinguishing agent prepared in example 3.

Fig. 6 is a graph showing the surface temperature changes of four lithium ion batteries before and after spraying the fire extinguishing agent prepared in example 3.

FIG. 7 shows the surface temperature changes of four lithium ion batteries before and after spraying the water mist fire extinguishing agent.

FIG. 8 is the surface temperature change of four lithium ion batteries before and after spraying the perfluorohexanone fire extinguishing agent.

FIG. 9 shows the surface temperature changes of four lithium ion batteries before and after spraying the ABC superfine dry powder extinguishing agent.

Detailed Description

For further illustration of the present invention, the following will describe in detail an organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for lithium ion battery fire and its preparation method with reference to the examples, which are obviously a part of the present invention, but they should not be construed as limiting the scope of the present invention.

Example 1

An organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which comprises the following raw material components in parts by weight: 500 parts of hydrophobic silica, 20 parts of acrylic acid, 10 parts of sodium bicarbonate, 20 parts of acrylamide, 5 parts of methyl methacrylate, 5 parts of ethyl methacrylate, 5 parts of butyl methacrylate, 5 parts of ethyl acrylate, 60 parts of N-isopropyl acrylamide, 20 parts of N- (2-hydroxyethyl) acrylamide, 1 part of N, N' -methylene bisacrylamide, 1 part of potassium persulfate and 4348 parts of deionized water, wherein the total weight part is 5000 parts.

An organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which is prepared by the following steps:

(1) weighing acrylic acid, dissolving in water, adding sodium bicarbonate for three times, and stirring at room temperature for 20min to obtain a mixed solution;

(2) pouring the mixed solution into a three-neck flask, respectively adding acrylamide, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, N-isopropylacrylamide, N- (2-hydroxyethyl) acrylamide and N, N' -methylene-bisacrylamide, and sealing; after the air in the flask was evacuated, nitrogen was introduced, and then the potassium persulfate solution was injected into the three-necked flask by means of a syringe. Reacting for 24 hours at room temperature to obtain a cross-linked polymer solution;

(3) removing the reaction device, pouring the solution into a glass bottle with a plug, placing the glass bottle at 85 ℃ for 5min to form crosslinked polymer hydrogel, and continuously standing at the temperature for 4h to obtain the crosslinked polymer hydrogel;

(4) crushing hydrogel, adding deionized water to make the hydrogel absorb water and swell, standing for 48 hours to make the gel uniformly absorb water;

(5) the specific surface area is 170m²Adding/g of hydrophobic silicon dioxide and the swelled hydrogel into a high-speed stirrer, and stirring at the rotating speed of 2400r/min for 9s to obtain an organic/inorganic hybrid core-shell structure fire extinguishing agent 1;

(6) and filling the prepared fire extinguishing agent final product into a general portable fire extinguishing steel cylinder, filling 1.5MPa of nitrogen, and sealing the steel cylinder for later use.

Example 2

An organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which comprises the following raw material components in parts by weight: 400 parts of hydrophobic silica, 25 parts of acrylic acid, 20 parts of sodium bicarbonate, 10 parts of acrylamide, 3 parts of methyl methacrylate, 2 parts of ethyl methacrylate, 5 parts of butyl methacrylate, 5 parts of ethyl acrylate, 20 parts of N-isopropyl acrylamide, 20 parts of hydroxyethyl methacrylate, 1 part of N, N' -methylene-bisacrylamide, 1 part of potassium persulfate and 4488 parts of deionized water, wherein the total weight part is 5000 parts.

An organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which is prepared by the following steps:

(1) weighing acrylic acid, dissolving in water, adding sodium bicarbonate for three times, and stirring at room temperature for 20min to obtain a mixed solution;

(2) pouring the mixed solution into a three-neck flask, respectively adding acrylamide, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, N-isopropylacrylamide, hydroxyethyl methacrylate and N, N' -methylene-bisacrylamide, and sealing; after the air in the flask was evacuated, nitrogen was introduced, and then the potassium persulfate solution was injected into the three-necked flask by means of a syringe. Reacting for 24 hours at room temperature to obtain a cross-linked polymer solution;

(3) removing the reaction device, pouring the solution into a glass bottle with a plug, placing the glass bottle at 85 ℃ for 5min to form crosslinked polymer hydrogel, and continuously standing at the temperature for 4h to obtain the crosslinked polymer hydrogel;

(4) crushing hydrogel, adding deionized water to make the hydrogel absorb water and swell, standing for 24h to make the gel uniformly absorb water;

(5) the specific surface area is 170m²Adding/g of hydrophobic silicon dioxide and the swelled hydrogel into a high-speed stirrer, and stirring at the rotating speed of 2400r/min for 8s to obtain an organic/inorganic hybrid core-shell structure fire extinguishing agent 2;

(6) and filling the prepared fire extinguishing agent final product into a general portable fire extinguishing steel cylinder, filling 1.5MPa of nitrogen, and sealing the steel cylinder for later use.

Example 3:

an organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which comprises the following raw material components in parts by weight: 700 parts of hydrophobic silica, 50 parts of acrylic acid, 35 parts of sodium bicarbonate, 80 parts of acrylamide, 3 parts of methyl methacrylate, 2 parts of ethyl methacrylate, 2 parts of butyl methacrylate, 3 parts of ethyl acrylate, 20 parts of N-isopropyl acrylamide, 30 parts of N- (2-hydroxyethyl) acrylamide, 1 part of N, N' -methylene bisacrylamide, 1 part of potassium persulfate and 4073 parts of deionized water, wherein the total weight is 5000 parts.

An organic/inorganic hybrid core-shell structure fire extinguishing agent suitable for extinguishing lithium ion battery fire, which is prepared by the following steps:

(1) weighing acrylic acid, dissolving in water, adding sodium bicarbonate for three times, and stirring at room temperature for 20min to obtain a mixed solution;

(2) pouring the mixed solution into a three-neck flask, respectively adding acrylamide, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, N-isopropylacrylamide, N- (2-hydroxyethyl) acrylamide and N, N' -methylene-bisacrylamide, and sealing; after the air in the flask was evacuated, nitrogen was introduced, and then the potassium persulfate solution was injected into the three-necked flask by means of a syringe. Reacting for 24 hours at room temperature to obtain a cross-linked polymer solution;

(3) removing the reaction device, pouring the solution into a glass bottle with a plug, placing the glass bottle at 85 ℃ for 5min to form crosslinked polymer hydrogel, and continuously standing at the temperature for 4h to obtain the crosslinked polymer hydrogel;

(4) crushing hydrogel, adding deionized water to make the hydrogel absorb water and swell, standing for 24h to make the gel uniformly absorb water;

(5) the specific surface area is 170m²Adding/g of hydrophobic silicon dioxide and the swelled hydrogel into a high-speed stirrer, and stirring at the rotating speed of 2400r/min for 11s to obtain an organic/inorganic hybrid core-shell structure fire extinguishing agent 3;

(6) and filling the prepared fire extinguishing agent final product into a general portable fire extinguishing steel cylinder, filling 1.5MPa of nitrogen, and sealing the steel cylinder for later use.

The performance of the organic/inorganic hybrid fire extinguishing agent with the core-shell structure prepared by the invention is detected, and the specific results are shown in the following table.

According to the GB4066.1-2004 (dry powder extinguishing agent) and GB4066.2-2004(ABC dry powder extinguishing agent) partial performance test methods, the self structural characteristics and the use conditions of the organic/inorganic hybrid core-shell structure extinguishing agent are combined to respectively measure the physical and chemical properties of the organic/inorganic hybrid core-shell structure extinguishing agent, such as bulk density, moisture retention property, fluidity, particle size, water repellency and the like.

Meanwhile, a fire extinguishing effectiveness comparison experiment of the fire extinguishing agent, the ABC type superfine dry powder fire extinguishing agent, the water mist fire extinguishing agent and the perfluorohexanone fire extinguishing agent prepared in the embodiment 3 on the lithium ion battery of the four-section 18650 ternary material system is carried out. When the fire extinguishing agent is sprayed under the pressure of 1.5MPa for 20s at the time of spraying and the air is released from the second lithium ion battery at the time of spraying, the spraying distance is 30cm above the second lithium ion battery. Fig. 6-9 are graphs showing the surface temperature changes of four lithium ion batteries before and after spraying different fire extinguishing agents, from which it can be seen that the different fire extinguishing agents show obvious differences in inhibiting the temperature rise of the lithium ion batteries, after the perfluorohexanone fire extinguishing agent (fig. 8) is released, the surface temperature of the second lithium ion battery is reduced for a short time and then rapidly and greatly increased, and the four lithium ion batteries are subjected to thermal runaway in sequence; after the ABC superfine dry powder extinguishing agent (figure 9) is released, the surface temperature of the second lithium ion battery is quickly reduced and then quickly rises, and thermal runaway occurs, but thermal runaway does not occur in the third section and the fourth section, namely the ABC superfine dry powder extinguishing agent cannot inhibit thermal runaway of a single lithium ion battery; the water mist (fig. 7) and the fire extinguishing agent (fig. 6) prepared in example 3 can inhibit not only the thermal runaway of a single lithium ion battery but also the thermal runaway spread of the lithium ion battery, but the fire extinguishing agent prepared in example 3 has a better effect of inhibiting the temperature rise of the lithium ion battery than the water mist, and the reignition does not occur within 30 min. The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.