Novel lithium battery fire extinguishing solvent

Abstract

According to the novel lithium battery fire extinguishing solvent disclosed by the invention, through the cooperation of phosphorus pentanitride, phase-stable ammonium nitrate, perfluorohexanone, polyacrylate, polyvinylpyrrolidone and hexamethyldisiloxane, the excellent properties of rapid fire extinguishing, long-acting cooling and after-combustion prevention are realized; phosphorus pentanitride and PSAN release nitrogen to jointly inhibit flames and prevent reburning with phosphate, perfluorohexanone provides cooling and prevents thermal runaway diffusion, polyacrylate and PVP improve the dispersity and stability of particles, and hydrophobicity of hexamethyldisiloxane ensures the performance stability of the fire extinguishing agent in storage and high-humidity environments. The aerosol form is adopted, so that the fire extinguishing particles can uniformly cover a fire source, and higher fire extinguishing efficiency can be realized by using a smaller amount of fire extinguishing particles.

Description

Technical Field

[0001] The invention belongs to the field of lithium battery fire extinguishing solvents, and in particular relates to a novel lithium battery fire extinguishing solvent. Background Art

[0002] With the widespread application of lithium batteries in electric vehicles, energy storage systems and consumer electronics, the risk of fire caused by thermal runaway has become a major safety hazard. When a lithium battery is overcharged, physically damaged externally or short-circuited internally, the chemical reaction in the battery quickly gets out of control, causing the battery temperature to rise sharply and releasing toxic gases and flammable substances (such as electrolyte solvents and hydrogen). This thermal runaway will not only cause violent flames or even explosions, but may also cause multiple battery modules to fail in a chain reaction, resulting in large-scale fires or secondary disasters. Traditional fire extinguishing methods have exposed many shortcomings when faced with such complex situations. The water mist fire extinguishing system mainly relies on the vaporization of water to absorb heat to achieve cooling, but because water cannot effectively penetrate into the battery, it is difficult to suppress the thermal runaway chain reaction of the lithium battery, and it may leave hidden dangers and cause re-ignition. In addition, water may react with the electrolyte of the lithium battery during the fire extinguishing process to generate flammable gases (such as hydrogen), increasing secondary dangers. Another commonly used type of gas fire extinguishing agent, such as carbon dioxide or perfluorohexanone, can quickly reduce the temperature in the initial stage, but because they cannot cover or penetrate into the deep chemical reaction area of ​​the battery, it is difficult to prevent the continued expansion of thermal runaway when used alone, and there is also a risk of re-ignition after the fire is extinguished.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, provide a new type of lithium battery fire extinguishing solvent, and solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0006] A novel lithium battery fire extinguishing solvent, the solvent is prepared by the following components by weight percentage: 40-60% of phosphorus pentanitride; 20-30% of ammonium nitrate; 10-20% of perfluorohexanone; 5-10% of polyacrylate; 1-5% of polyvinyl pyrrolidone; 1-5% of hexamethyldisiloxane. All components in the present application are mixed, dried and crushed to form micron-sized particles. The surface of these particles is coated with perfluorohexanone and wrapped with hexamethyldisiloxane and polyacrylate layers to ensure the stability and uniformity of the particles.

[0007] Phosphorus pentanitride is in the form of micron-sized powder in this application, and the particle size is controlled between 2-5 microns. The powder is chemically stable, insoluble in water, and easy to disperse during the mixing process. At high temperatures, phosphorus pentanitride releases a large amount of nitrogen when it decomposes and forms a phosphate coating, which effectively blocks the oxygen supply of the fire source and the spread of flames. At the same time, the phosphate layer also forms a passivation film on the surface of the material to prevent re-ignition and ensure continued safety after the fire is extinguished.

[0008] Ammonium nitrate is present in the form of microcrystalline powder in this application, and the particle size is also controlled between 2-5 microns. It has been subjected to phase stabilization treatment to avoid crystallization changes or performance failure after being exposed to moisture. At high temperatures, ammonium nitrate decomposes to release oxygen and nitrogen, and reduces the temperature of the fire source through an endothermic process. After combining with phosphorus pentanitride, the two form a uniform redox system, which jointly improves the efficiency of fire extinguishing.

[0009] Perfluorohexanone is in the form of a liquid in this application, uniformly adsorbed on the surface of the dried powder particles. The liquid is chemically stable and highly volatile, and quickly cools the fire source by absorbing heat and vaporizing during fire extinguishing. During the combustion process, perfluorohexanone can also effectively reduce toxic gas emissions caused by thermal runaway. Through the drying process, it is stably distributed on the surface of the particles, ensuring that the particles can provide a lasting cooling effect and anti-reignition function after spraying.

[0010] The polyacrylate is in the form of a viscous liquid or resin in this application, which is first dissolved in an ethanol-water mixture (98:2) and then combined with the powder component. After drying, it forms a bonding layer on the surface of the particles, ensuring the stability of the particle structure and preventing dust from flying. The polyacrylate also improves the adhesion of the particles, preventing particle agglomeration during storage and spraying, and ensuring uniform release of the aerosol.

[0011] Polyvinyl pyrrolidone is present in the form of a powdered solid in this application, coated on the surface of the particles, and acts as a dispersant. It ensures that the particles do not aggregate after mixing and remain stably dispersed during storage. In addition, the film-forming property of polyvinyl pyrrolidone helps to isolate the particles from each other, improving the storage stability and spraying effect of the aerosol.

[0012] The hexamethyldisiloxane in this application is in the form of a transparent liquid, which is evenly coated on the surface of the particles. Due to its strong hydrophobicity, hexamethyldisiloxane prevents the particles from absorbing moisture and agglomerating. At the same time, it improves the fluidity and dispersibility of the particles during spraying, ensures that the aerosol remains uniform during the release process, and enhances the stability of the fire extinguishing agent in complex environments.

[0013] Phosphorus pentanitride and ammonium nitrate work synergistically under high temperature conditions. Both release nitrogen at the same time, rapidly reducing the oxygen concentration of the fire source and blocking the spread of flames. In addition, the phosphate passivation layer produced by phosphorus pentanitride effectively isolates the flammable materials in the fire source, while the oxygen released by ammonium nitrate enhances the combustion suppression process and prevents re-ignition. This combination ensures rapid fire extinguishing while avoiding the risk of re-ignition caused by excessive oxidation.

[0014] Perfluorohexanone achieves rapid cooling of the fire source through heat absorption and gasification, and together with the phosphate passivation layer formed by phosphorus pentanenitride, it inhibits the thermal runaway reaction. The volatility of perfluorohexanone helps to quickly cool the surface of the fire source, while the passivation effect of phosphorus pentanenitride prevents oxygen from re-entering the fire source, ensuring that the fire is completely extinguished and reducing the risk of re-ignition. This combination of synergistic cooling and chemical inhibition improves the long-term effectiveness of the fire extinguishing agent.

[0015] Polyacrylate acts as a binder to form a stable protective film on the surface of the particles, while polyvinyl pyrrolidone acts as a dispersant to ensure that the particles do not agglomerate during storage and spraying. The combination of the two enhances the dispersibility and adhesion of the particles, allowing the fire extinguishing particles to be evenly distributed and cover the fire source during spraying, improving the fire extinguishing efficiency and the stability of the particles.

[0016] Hexamethyldisiloxane forms a hydrophobic film on the surface of the particles, preventing the particles from agglomerating due to moisture absorption and improving their fluidity. After combining with other ingredients, hexamethyldisiloxane improves the environmental adaptability of the particles and maintains the stability of the fire extinguishing agent even in high humidity environments. This hydrophobicity also ensures the safety of the particles during long-term storage and the reliability of their fire extinguishing performance.

[0017] Optionally, the preparation method comprises the following steps:

[0018] Step (1): In a low humidity environment, weighed phosphorus pentanitride and ammonium nitrate are added into a mixing container in proportion, and mixed evenly to obtain product ①.

[0019] Step (2): adding polyacrylate to ethanol in proportion, and then stirring at room temperature until the polyacrylate is completely dissolved to form a mixed solution ①;

[0020] Step (3): Pour the mixed solution ① into phosphorus pentanitride and ammonium nitrate, add the mixed solution in sequence, and continue stirring for 30 minutes. After stirring evenly, a mixed solution ② is obtained.

[0021] Step (4): add the weighed perfluorohexanone dropwise to the mixed solution ②. After the addition is completed, continue stirring for 30 minutes. After mixing evenly, the product ② is obtained.

[0022] Step (5): During the mixing process of product ②, polyvinyl pyrrolidone and hexamethyldisiloxane are added to product ② in sequence, and stirring is maintained for 20-30 minutes to obtain a mixture.

[0023] Step (6): the mixture is evenly spread in a dryer for drying, and the dried material is processed by a pulverizing device to obtain a fire extinguishing solvent.

[0024] Optionally, the stirring time in step (1) is 1-2 h, and the humidity when obtaining product ① in step (1) is less than 10%.

[0025] Optionally, in step (2), the ratio of polyacrylate to ethanol is 98:2, and the stirring time when the polyacrylate and ethanol are mixed is 20 minutes.

[0026] Optionally, in step (4), the dripping rate of perfluorohexanone is not more than 10 ml per minute.

[0027] Optionally, the temperature during the drying process in step (6) is 60-80° C. and the drying time is 8-12 hours.

[0028] Optionally, the fire extinguishing solvent after crushing in step (6) is in granular form, and the diameter of each particle is 2-5 microns.

[0029] Optionally, after obtaining the fire extinguishing solvent, the crushed particles are evenly loaded into an aerosol can and filled with inert gas.

[0030] Optionally, the inert gas is one of nitrogen and argon.

[0031] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all the advantages described below at the same time:

[0032] The novel lithium battery fire extinguishing solvent of the present invention achieves excellent performances of rapid fire extinguishing, long-term cooling and re-ignition prevention through the combination of phosphorus pentanitride, phase-stable ammonium nitrate, perfluorohexanone and polyacrylate, polyvinyl pyrrolidone and hexamethyldisiloxane; wherein phosphorus pentanitride and PSAN release nitrogen and phosphate to jointly suppress flames and prevent re-ignition, perfluorohexanone provides cooling and temperature reduction to prevent thermal runaway diffusion, polyacrylate and PVP improve the dispersibility and stability of particles, and the hydrophobicity of hexamethyldisiloxane ensures the performance stability of the fire extinguishing agent in storage and high humidity environments; the aerosol form is adopted, so that the fire extinguishing particles can evenly cover the fire source, and higher fire extinguishing efficiency can be achieved with less dosage.

[0033] The specific embodiments of the present invention are described in further detail below. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0036] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0037] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0038] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0039] In this embodiment, a novel lithium battery fire extinguishing solvent is provided. The solvent is prepared from the following components by weight percentage: 40-60% phosphorus pentanitride; 20-30% ammonium nitrate; 10-20% perfluorohexanone; 5-10% polyacrylate; 1-5% polyvinyl pyrrolidone; and 1-5% hexamethyldisiloxane.

[0040] The preparation method of this embodiment comprises the following steps:

[0041] Step (1): In a low humidity environment, weighed phosphorus pentanitride and ammonium nitrate are added into a mixing container in proportion, and mixed evenly to obtain product ①.

[0042] Step (2): adding polyacrylate to ethanol in proportion, and then stirring at room temperature until the polyacrylate is completely dissolved to form a mixed solution ①;

[0043] Step (3): Pour the mixed solution ① into phosphorus pentanitride and ammonium nitrate, add the mixed solution in sequence, and continue stirring for 30 minutes. After stirring evenly, a mixed solution ② is obtained.

[0044] Step (4): add the weighed perfluorohexanone dropwise to the mixed solution ②. After the addition is completed, continue stirring for 30 minutes. After mixing evenly, the product ② is obtained.

[0045] Step (5): During the mixing process of product ②, polyvinyl pyrrolidone and hexamethyldisiloxane are added to product ② in sequence, and stirring is maintained for 20-30 minutes to obtain a mixture.

[0046] Step (6): the mixture is evenly spread in a dryer for drying, and the dried material is processed by a pulverizing device to obtain a fire extinguishing solvent.

[0047] In this embodiment, the stirring time in step (1) is 1-2 hours, and the humidity when obtaining product ① in step (1) is less than 10%.

[0048] In this embodiment, the ratio of polyacrylate to ethanol in step (2) is 98:2, and the stirring time when the polyacrylate and ethanol are mixed is 20 minutes.

[0049] In this embodiment, the dripping speed of perfluorohexanone in step (4) does not exceed 10 ml per minute.

[0050] In this embodiment, the temperature during the drying process in step (6) is 60-80° C., and the drying time is 8-12 hours.

[0051] In this embodiment, the fire extinguishing solvent after crushing in step (6) is in granular form, and the diameter of each particle is 2-5 microns.

[0052] In this embodiment, after obtaining the fire extinguishing solvent, the crushed particles are evenly loaded into an aerosol can and filled with inert gas.

[0053] In this embodiment, the inert gas is one of nitrogen and argon.

[0054] The present invention will now be further described in detail with reference to embodiments.

[0055] It should be noted that all raw materials in the examples of the present invention were obtained through commercial sources.

[0056] Embodiment 1: A novel lithium battery fire extinguishing solvent, the solvent is prepared by the following components in weight percentage: 50% phosphorus pentanitride, 25% ammonium nitrate, 15% perfluorohexanone, 5% polyacrylate, 3% polyvinyl pyrrolidone, and 2% hexamethyldisiloxane.

[0057] The preparation method of the novel lithium battery fire extinguishing solvent comprises the following steps:

[0058] Step (1): Add weighed phosphorus pentanitride and ammonium nitrate into a mixing container in proportion, and stir for 1 hour in an environment with a humidity below 10% to obtain product ①.

[0059] Step (2): dissolve polyacrylate in ethanol (ratio 98:2) and stir at room temperature for 20 minutes to obtain a mixed solution ①.

[0060] Step (3): slowly pour the above mixed solution ① into the product ① and continue stirring for 30 minutes to obtain a mixed solution ②.

[0061] Step (4): perfluorohexanone is added dropwise to the mixed solution ② at a rate not exceeding 10 ml per minute, and stirred for 30 minutes to obtain a uniform product ②.

[0062] Step (5): Add polyvinyl pyrrolidone and hexamethyldisiloxane to product ② in sequence and stir for 20 minutes to obtain a mixture.

[0063] Step (6): The mixture is dried at 60°C for 8 hours and then processed into particles of 2-5 microns by a pulverizing device.

[0064] Step (7): The crushed particles are placed in an aerosol can and filled with nitrogen.

[0065] Example 2: A novel lithium battery fire extinguishing solvent, the solvent is prepared from the following ingredients by weight percentage: 40% phosphorus pentanitride, 30% ammonium nitrate, 10% perfluorohexanone, 10% polyacrylate, 5% polyvinyl pyrrolidone, and 5% hexamethyldisiloxane, wherein the preparation method of the novel lithium battery fire extinguishing solvent in Example 2 is the same as that in Example 1.

[0066] Example 3: A novel lithium battery fire extinguishing solvent, the solvent is prepared from the following ingredients in weight percentage: 60% phosphorus pentanitride, 20% ammonium nitrate, 10% perfluorohexanone, 5% polyacrylate, 3% polyvinyl pyrrolidone, and 2% hexamethyldisiloxane, wherein the preparation method of the novel lithium battery fire extinguishing solvent in Example 3 is the same as that in Example 1.

[0067] Control Example: A water mist fire extinguishing solvent was used, and the solvent was prepared by the following components by weight percentage: 99% water and 1% polyvinyl pyrrolidone;

[0068] The preparation method is as follows: water and polyvinyl pyrrolidone are mixed, stirred at room temperature for 30 minutes to ensure that the polyvinyl pyrrolidone is completely dissolved, and the mixed solution is loaded into a high-pressure spray tank and filled with nitrogen.

[0069] Test example: According to the formula of the new lithium battery fire extinguishing solvent, examples 1-3 and water mist fire extinguishing solvent (control example) were tested experimentally. The test used different formulas and fire extinguishing agent forms to simulate the fire scene caused by thermal runaway of lithium batteries to evaluate the fire extinguishing performance and re-ignition control ability of each solvent. The experiment mainly examined key indicators such as fire extinguishing time, re-ignition risk, and temperature change of the fire source.

[0070] The experiment used a lithium iron phosphate battery (LiFePO4) with a capacity of 243Ah, and triggered a fire by overcharging to induce thermal runaway. The fire extinguishing agent test was divided into two forms: Examples 1-3 used aerosol form to release the fire extinguishing agent through nitrogen injection; the control example used a water mist fire extinguishing system to extinguish the fire. The experiment was carried out under the conditions of an ambient temperature of 25°C and a relative humidity of 45%. Each group of tests was repeated 3 times and the average value was taken. The specific experimental results are detailed in Table 1.

[0071] Table 1: Fire extinguishing performance test results of fire extinguishing solvents

[0072]

[0073] According to Table 1, the fire extinguishing time in Example 3 is the shortest, only 10 seconds, which shows the key role of a high proportion of phosphorus pentanilide in fire extinguishing. Phosphorus pentanilide can quickly release nitrogen in a high temperature environment, blocking the oxygen supply required for flame propagation, and generating phosphates to form a passivation film on the surface of the fire source. This dual inhibition mechanism can not only effectively terminate the combustion reaction of lithium battery fires, but also quickly cool the fire source to prevent thermal runaway chain reactions caused by high temperatures. In addition, compared with other formulations, the high proportion of phosphorus pentanilide in Example 3 accelerates the fire extinguishing process, allowing the aerosol particles to cover the entire fire source in a very short time, thereby greatly shortening the fire extinguishing time.

[0074] In terms of re-ignition risk control, Examples 1-3 all showed excellent performance, while the water mist fire extinguishing agent had a 33% re-ignition probability in the control test. This is mainly because perfluorohexanone not only quickly cools the battery surface through gasification heat absorption during the fire extinguishing process, but also effectively reduces the harmful gases generated during the combustion process. In addition, perfluorohexanone has high molecular stability and can permanently cover the fire source after extinguishing the fire, which helps to suppress the continuous release of flammable gases inside the battery. These characteristics make its cooling and re-ignition prevention capabilities far superior to water mist systems that rely solely on physical cooling.

[0075] The experimental results of the temperature change range show that Example 3 has the largest temperature reduction of 50°C, while the water mist fire extinguishing agent only reduced the temperature by 30°C. This is because the aerosol fire extinguishing agent absorbs a large amount of heat during the chemical reaction process, and the well-dispersed aerosol particles can fully cover the combustion area, enhancing the cooling effect. In contrast, the water mist fire extinguishing agent mainly cools the fire source by absorbing heat through the vaporization of water, but its cooling range is limited, and it may evaporate rapidly under high temperature conditions, resulting in insufficient cooling effect, especially when the thermal runaway of the lithium battery continues.

[0076] In terms of the consumption of fire extinguishing agent, the consumption of aerosol fire extinguishing agent in the embodiment is significantly lower than that of water mist fire extinguishing agent, showing its higher fire extinguishing efficiency. This is due to the high dispersibility and chemical inhibition of aerosol fire extinguishing agent in the fire extinguishing process. With less fire extinguishing agent, the spread of flames can be stopped in a short time and re-ignition can be prevented. On the contrary, water mist fire extinguishing agent mainly relies on the evaporation and cooling of a large amount of water, so the consumption is large and the cooling capacity is relatively insufficient. Therefore, the aerosol fire extinguishing agent in the embodiment has significant advantages in efficient fire extinguishing and resource conservation, and is a preferred solution for dealing with lithium battery fires.

[0077] The present invention is not limited to the above-mentioned embodiments. Anyone should be aware that any structural changes made under the enlightenment of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention. The technology, shape, and structural parts not described in detail in the present invention are all well-known technologies.

Claims

1. A new type of lithium battery fire extinguishing solvent, characterized in that: The solvent is prepared from the following components by weight percentage: 40-60% of phosphorus pentanitride; 20-30% of ammonium nitrate; 10-20% of perfluorohexanone; 5-10% of polyacrylate; 1-5% of polyvinyl pyrrolidone; and 1-5% of hexamethyldisiloxane.

2. A novel lithium battery fire extinguishing solvent according to claim 1, characterized in that: The preparation method comprises the following steps: Step (1): In a low humidity environment, weighed phosphorus pentanitride and ammonium nitrate are added into a mixing container in proportion, and mixed evenly to obtain product ①. Step (2): adding polyacrylate to ethanol in proportion, and then stirring at room temperature until the polyacrylate is completely dissolved to form a mixed solution ①; Step (3): Pour the mixed solution ① into phosphorus pentanitride and ammonium nitrate, add the mixed solution in sequence, and continue stirring for 30 minutes. After stirring evenly, a mixed solution ② is obtained. Step (4): add the weighed perfluorohexanone dropwise to the mixed solution ②. After the addition is completed, continue stirring for 30 minutes. After mixing evenly, the product ② is obtained. Step (5): During the mixing process of product ②, polyvinyl pyrrolidone and hexamethyldisiloxane are added to product ② in sequence, and stirring is maintained for 20-30 minutes to obtain a mixture. Step (6): the mixture is evenly spread in a dryer for drying, and the dried material is processed by a pulverizing device to obtain a fire extinguishing solvent.

3. A novel lithium battery fire extinguishing solvent according to claim 1, characterized in that: The stirring time in step (1) is 1-2 hours, and the humidity when obtaining product ① in step (1) is less than 10%.

4. A novel lithium battery fire extinguishing solvent according to claim 1, characterized in that: In step (2), the ratio of polyacrylate to ethanol is 98:2, and the stirring time when the polyacrylate and ethanol are mixed is 20 minutes.

5. A novel lithium battery fire extinguishing solvent according to claim 1, characterized in that: When perfluorohexanone is added dropwise in step (4), the dropping speed does not exceed 10 ml per minute.

6. A novel lithium battery fire extinguishing solvent according to claim 1, characterized in that: The temperature during the drying process in step (6) is 60-80° C. and the drying time is 8-12 hours.

7. A novel lithium battery fire extinguishing solvent according to claim 1, characterized in that: The fire extinguishing solvent after crushing in step (6) is in granular form, and the diameter of each particle is 2-5 microns.

8. A novel lithium battery fire extinguishing solvent according to claim 1, characterized in that: After obtaining the fire extinguishing solvent, the crushed particles are evenly loaded into an aerosol can and filled with inert gas.

9. A novel lithium battery fire extinguishing solvent according to claim 8, characterized in that: The inert gas is one of nitrogen and argon.

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