Fire extinguishing agent special for thermosensitive lithium battery and preparation method of fire extinguishing agent

Abstract

The invention relates to the technical field of fire extinguishing agents, and discloses a thermosensitive lithium battery special fire extinguishing agent and a preparation method thereof.The thermosensitive lithium battery special fire extinguishing agent comprises, by weight, 1-5 parts of a surfactant, 10-25 parts of an aprotic solvent, 2-5 parts of a fire extinguishing agent, 2-5 parts of a microcapsule agent, 3-10 parts of a temperature reducing agent, 2-10 parts of a thermosensitive expanding agent, 1-8 parts of a thermosensitive thickening agent and 70-100 parts of deionized water. According to the special fire extinguishing agent provided by the invention, a thermosensitive expanding agent, a thermosensitive thickening agent and a microcapsule medicament are added into a water-based fire extinguishing agent. And when meeting high temperature of flame, the fire extinguishing agent generates thermal expansion and increases viscosity, so that the adhesive force of the water-based fire extinguishing agent on the surface of the lithium battery is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of fire extinguishing agents, and in particular to a fire extinguishing agent specially used for heat-sensitive lithium batteries and a preparation method thereof. Background Art

[0002] In terms of the application of fire extinguishing agents, when a lithium battery catches fire, its internal core temperature rises sharply due to thermal runaway, and the flame quickly penetrates the surface of the battery to form a deflagration. To extinguish the fire, it is not only necessary to extinguish the open flame, but also to continue to cool down until the battery stops heating up and does not re-ignite. At present, especially in open spaces, the use of various gas fire extinguishing agents, dry powder fire extinguishing agents, aerosol fire extinguishing agents, etc. to extinguish lithium battery fires has not been able to effectively solve the problem of battery re-ignition; and the use of water and ordinary water-based fire extinguishing agents to extinguish lithium battery fires, although it can effectively extinguish the fire, is very easy to lose during the fire extinguishing process, and still requires a large amount of water and fire extinguishing agents to suppress the re-ignition of thermal runaway lithium batteries. Summary of the invention

[0003] Technical problems solved by the present invention:

[0004] The invention is used to solve the problem of poor fire extinguishing effect of water-based fire extinguishing agents in the prior art.

[0005] In view of the above technical problems, the purpose of the present invention is to provide a fire extinguishing agent for heat-sensitive lithium batteries and a preparation method thereof. Specifically, the technical solution adopted by the present invention is as follows:

[0006] First, the present invention provides a special fire extinguishing agent for thermosensitive lithium batteries. The raw material components, measured by weight, include 1-5 parts of surfactant, 10-25 parts of aprotic solvent, 2-5 parts of fire extinguishing agent, 2-5 parts of microcapsule agent, 3-10 parts of cooling agent, 2-10 parts of thermosensitive expansion agent, 1-8 parts of thermosensitive thickener, and 70-100 parts of deionized water.

[0007] According to some preferred embodiments, the aforementioned raw material components preferably include 2-5 parts of surfactant, 10-15 parts of aprotic solvent, 2-5 parts of fire extinguishing agent, 2-5 parts of microcapsule agent, 3-6 parts of cooling agent, 2-5 parts of thermosensitive expansion agent, 1-3 parts of thermosensitive thickener, and 70-80 parts of deionized water.

[0008] According to some preferred embodiments, the surfactant includes at least one of a hydrocarbon surfactant and a fluorine surfactant; among the aforementioned, the hydrocarbon surfactant includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and α-olefin sulfonate; the fluorine surfactant includes at least one of perfluorooctane sulfonate, perfluorohexane sulfonate, perfluorooctanoic acid, and perfluorohexanoic acid.

[0009] According to some preferred embodiments, the aprotic solvent includes a dimethylamine compound, specifically at least one of dimethylacetamide, N,N-dimethylformamide, and hexamethylphosphoramide.

[0010] According to some preferred embodiments, the fire extinguishing agent includes an α-hydroxypropionate organic compound, specifically including at least one of potassium dihydroxypropionate, sodium lactate, and calcium propionate.

[0011] According to some preferred embodiments, the microcapsule drug is made of perfluorohexanone as the core material, ethyl cellulose as the inner shell material, and SiO2 as the outer shell material. The specific preparation method is:

[0012] After dispersing perfluorohexanone in the solvent-perfluorocyclic ether, an emulsifier (emulsifier is Tween-80, emulsifier accounts for 0.5-2wt%) is added for high-speed stirring (12000rpm, 5min) to obtain an emulsion. In a nitrogen atmosphere, vinyl cellulose, azobisisobutyronitrile (accounting for 1-3wt% of ethyl cellulose), methacrylic acid, and methyl stearate are added to the emulsion, and the reaction system is heated to 60-80°C for 2h. After the reaction is completed, ammonia water is added to adjust the pH value of the system to 10, and then TEOS is added. After stirring for 0.5-2h, the microcapsule agent is obtained by filtering, washing (alternating washing with ethanol and water), and drying. The mass ratio of perfluorohexanone, vinyl cellulose, methacrylic acid, methyl stearate, and TEOS is 50:1:0.2-0.8:0.2-0.5:0.8-1.2.

[0013] According to some preferred embodiments, the temperature reducing agent includes a trihydroxy salt organic compound, specifically at least one of triisopropanolamine, triethylamine, and triethanolamine.

[0014] According to some preferred embodiments, the heat-sensitive expansion agent includes aluminosilicate inorganic compounds, specifically including at least one of zeolite, kaolinite, montmorillonite, illite, feldspar and mica.

[0015] According to some preferred embodiments, the thermosensitive thickener includes non-ionic cellulose ether organic compounds, specifically including at least one of hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and sodium carboxymethyl cellulose.

[0016] According to some preferred embodiments, the deionized water is ultrapure water or distilled water.

[0017] Second, the present invention provides a method for preparing the aforementioned heat-sensitive lithium battery-specific fire extinguishing agent, comprising the following steps:

[0018] (1) adding a surfactant, a fire extinguishing agent, and a temperature reducing agent to an aprotic solvent and fully dissolving them;

[0019] (2) adding the solution obtained in (1) into deionized water and stirring evenly;

[0020] (3) heating the solution obtained in (2) to 35-50° C., adding a thermosensitive thickener and stirring evenly;

[0021] (4) cooling the solution obtained in (3) to room temperature, adding a thermosensitive expansion agent and a microcapsule agent and stirring evenly;

[0022] (5) The solution obtained in (4) is allowed to stand for defoaming to obtain a fire extinguishing agent.

[0023] The technical mechanism and beneficial effects adopted by the present invention are as follows:

[0024] The special fire extinguishing agent provided by the present invention is a water-based fire extinguishing agent with a heat-sensitive expansion agent, a heat-sensitive thickener, and a microcapsule agent. When exposed to high flame temperature, the fire extinguishing agent generates thermal expansion and increases viscosity, thereby enhancing the adhesion of the water-based fire extinguishing agent on the surface of the lithium battery; by coating perfluorohexanone, its release before it takes effect is reduced, and a double-shell coating structure is adopted to further enhance the coating effect, while also overcoming the stability problem of ethyl cellulose alone; in addition, by grafting and modifying cellulose with methacrylic acid and methyl stearate, the weather resistance of cellulose is further enhanced. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0026] Example 1

[0027] This embodiment provides a method for preparing a fire extinguishing agent for a thermal-sensitive lithium battery, comprising the following steps:

[0028] Weigh 2 parts of sodium dodecyl sulfate, 10 parts of dimethylacetamide, 2 parts of potassium dihydroxypropionate, 3 parts of microcapsule agent, 4 parts of triisopropanolamine, 1 part of kaolinite, 1 part of montmorillonite, 2 parts of sodium carboxymethyl cellulose and 75 parts of deionized water in proportion.

[0029] The preparation method of the microcapsule agent is to disperse perfluorohexanone in perfluorocyclic ether, add an emulsifier (emulsifier is Tween-80, emulsifier accounts for 1wt%), mix and stir at high speed (12000rpm, 5min) to obtain an emulsion. The volume ratio of the emulsion to perfluorohexanone is 1:4. Under a nitrogen atmosphere, vinyl cellulose, azobisisobutyronitrile (accounting for 2wt% of ethyl cellulose), methacrylic acid, and methyl stearate are added to the emulsion, and the reaction system is heated to 70°C for 2h. After the reaction is completed, ammonia water is added to adjust the pH value of the system to 10, and then TEOS is added. After stirring for 1h, the microcapsule agent is obtained by filtering, washing alternately with ethanol and water, and drying. The mass ratio of perfluorohexanone, vinyl cellulose, methacrylic acid, methyl stearate, and TEOS is 50:1:0.5:0.3:1.

[0030] (1) adding sodium lauryl sulfate, potassium dihydroxypropionate, microcapsule agent, and triisopropanolamine to dimethylacetamide and fully dissolving them;

[0031] (2) adding the solution obtained in (1) into deionized water and stirring evenly;

[0032] (3) heating the solution obtained in (2) to 50° C., adding sodium carboxymethyl cellulose and stirring evenly;

[0033] (4) The solution obtained in (3) was allowed to stand for 12 h, then cooled to room temperature, and kaolinite and montmorillonite were added and stirred evenly;

[0034] (5) The solution obtained in (4) was allowed to stand for 24 hours to defoam and obtain a fire extinguishing agent.

[0035] Comparative Example 1

[0036] The difference between this comparative example and Example 1 is that sodium carboxymethyl cellulose is not added.

[0037] Comparative Example 2

[0038] The difference between this comparative example and Example 1 is that kaolin and montmorillonite are not added.

[0039] Comparative Example 3

[0040] The difference between this comparative example and Example 1 is that methacrylic acid and methyl stearate are not added.

[0041] Test example

[0042] The fire extinguishing performance of Example 1 and Comparative Examples 1-3 was measured by selecting 150Ah lithium iron phosphate soft pack batteries (size: 8mm*118mm*155mm) with 100% SOC and testing them in an explosion-proof box. A 200W heating rod was used to induce thermal runaway of the battery. The heating rod was turned off after the battery thermal runaway. A water mist fire extinguishing system was set above the explosion-proof box. The test results are shown in Table 1. max : Maximum battery surface temperature, V 降 : average cooling rate when the maximum temperature of the battery surface drops to 50℃, t: fire extinguishing time.

[0043] Table 1 Measurement results

[0044] Measurement indicators Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 <![CDATA[T max / ℃]]> 452 455 461 458 <![CDATA[V 降 / (℃ / s)]]> 0.357 0.303 0.312 0.274 t / s 450 486 461 503

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fire extinguishing agent for thermal-sensitive lithium batteries, characterized in that: The raw material components are calculated by weight and include 1-5 parts of surfactant, 10-25 parts of aprotic solvent, 2-5 parts of fire extinguishing agent, 2-5 parts of microcapsule agent, 3-10 parts of cooling agent, 2-10 parts of thermal expansion agent, 1-8 parts of thermal thickener and 70-100 parts of deionized water.

2. The fire extinguishing agent for thermal-sensitive lithium batteries according to claim 1, characterized in that: The raw material components are calculated by weight and include 2-5 parts of surfactant, 10-15 parts of aprotic solvent, 2-5 parts of fire extinguishing agent, 2-5 parts of microcapsule agent, 3-6 parts of cooling agent, 2-5 parts of thermal expansion agent, 1-3 parts of thermal thickener and 70-80 parts of deionized water.

3. The fire extinguishing agent for thermal-sensitive lithium batteries according to claim 1, characterized in that: The surfactant includes at least one of a hydrocarbon surfactant and a fluorine surfactant; the hydrocarbon surfactant includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and α-olefin sulfonate; the fluorine surfactant includes at least one of perfluorooctane sulfonate, perfluorohexane sulfonate, perfluorooctanoic acid, and perfluorohexanoic acid; and / or the aprotic solvent includes at least one of dimethylacetamide, N,N-dimethylformamide, and hexamethylphosphoramide.

4. The fire extinguishing agent for thermal-sensitive lithium batteries according to claim 1, characterized in that: The heat-sensitive expander includes at least one of zeolite, kaolinite, montmorillonite, illite, feldspar and mica; and / or the heat-sensitive thickener includes at least one of hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and sodium carboxymethyl cellulose.

5. The fire extinguishing agent for thermal-sensitive lithium batteries according to claim 1, characterized in that: The fire extinguishing agent includes at least one of potassium dihydroxypropionate, sodium lactate, and calcium propionate; and / or the cooling agent includes at least one of triisopropanolamine, triethylamine, and triethanolamine.

6. The fire extinguishing agent for heat-sensitive lithium batteries according to any one of claims 1 to 5, characterized in that: The microcapsule drug is made of perfluorohexanone as the core material, ethyl cellulose as the inner shell material, and SiO2 as the outer shell material.

7. The fire extinguishing agent for thermal-sensitive lithium batteries according to claim 6, characterized in that: The preparation method of the microcapsule medicament is as follows: (1) dispersing perfluorohexanone in a solvent, adding an emulsified liquid, blending and stirring at a high speed to obtain an emulsion; (2) Adding vinyl cellulose, azobisisobutyronitrile, methacrylic acid and methyl stearate to the emulsion under a nitrogen atmosphere, heating the reaction system, adjusting the pH of the system to be alkaline after the reaction is completed, adding TEOS, stirring, filtering, washing and drying to obtain a microcapsule agent.

8. The fire extinguishing agent for thermal-sensitive lithium batteries according to claim 7, characterized in that: The emulsifier in the emulsion is Tween-80, and the solvent is perfluorocyclic ether.

9. The fire extinguishing agent for thermal-sensitive lithium batteries according to claim 7, characterized in that: The mass ratio of perfluorohexanone, vinyl cellulose, methacrylic acid, methyl stearate and TEOS is 50:1:0.2-0.8:0.2-0.5:0.8-1.2, and azobisisobutyronitrile accounts for 1-3wt% of ethyl cellulose.

10. A method for preparing a fire extinguishing agent for a thermosensitive lithium battery as claimed in any one of claims 1 to 9, characterized in that: The steps include: (1) adding a surfactant, a fire extinguishing agent, a microcapsule agent, and a cooling agent to an aprotic solvent and fully dissolving them; (2) adding the solution obtained in (1) into deionized water and stirring evenly; (3) heating the solution obtained in (2), adding a thermosensitive thickener and stirring evenly; (4) cooling the solution obtained in (3) to room temperature, adding a heat-sensitive expansion agent and stirring evenly; (5) The solution obtained in (4) is allowed to stand for defoaming to obtain a fire extinguishing agent.