Composite lithium battery fire extinguishing agent and preparation method and application thereof

Abstract

The present application belongs to the technical field of fire extinguishing agent, and particularly relates to a composite lithium battery fire extinguishing agent, a preparation method and application thereof. The composite lithium battery fire extinguishing agent comprises epoxy resin, melamine polyphosphate, ammonium polyphosphate, aluminum silicate cotton and a dispersing agent. When the composite lithium battery fire extinguishing agent is used for extinguishing fire, the ammonium polyphosphate is decomposed by heat to generate inorganic acids such as phosphoric acid and pyrophosphoric acid, the inorganic acids can undergo esterification reaction with the epoxy groups in the epoxy resin to make the epoxy resin dehydrate to form carbonized substances, the melamine polyphosphate is decomposed by heat to generate nitrogen and carbonized substances, and the carbonized substances form a porous carbon layer under the action of the nitrogen and other gases generated in the process of the decomposition of the melamine polyphosphate by heat. The porous carbon layer can prevent heat transfer and oxygen diffusion, and further improve the fire extinguishing effect and shorten the fire extinguishing time.

Description

Technical Field

[0001] This invention belongs to the field of fire extinguishing agent technology, specifically relating to a composite lithium battery fire extinguishing agent, its preparation method, and its application. Background Technology

[0002] Lithium-ion batteries are a type of rechargeable battery that primarily functions by the movement of lithium ions between the positive and negative electrodes. Lithium-ion batteries possess advantages such as high energy density, high average output voltage, low self-discharge, no memory effect, wide operating temperature range, excellent cycle performance, fast charging speed, high charging efficiency, high output power, and long lifespan. They are widely used in portable electronic devices, electric vehicles, aerospace, and defense industries.

[0003] However, accidents caused by thermal runaway of lithium-ion batteries leading to fires are frequent in the new energy vehicle sector, posing a significant safety hazard. Traditional fire extinguishing agents cannot extinguish combustion at its source, resulting in a high risk of reignition. Specifically, heptafluoropropane and perfluorohexanone fire extinguishing agents are only suitable for lithium battery fires in enclosed spaces; there are no simple and effective fire extinguishing devices for lithium battery fires in open spaces.

[0004] To address the aforementioned technical problems, patent document CN113262420B discloses a pressurized fire extinguisher for lithium batteries. This pressurized fire extinguisher is filled with an extinguishing agent, which comprises the following raw material components in parts by weight: 30-50 parts by weight of clay with a particle size of 500-600 mesh, 2-6 parts by weight of a foaming agent, 35-70 parts by weight of water, 1 wt%-3 wt% of silicone oil (based on the total mass of clay, foaming agent, and water), and 0.5 wt%-1 wt% of ethylene glycol (based on the total mass of clay, foaming agent, and water). The foaming agent is a mixture selected from sodium dodecyl sulfate and pine oil, with a mass ratio of sodium dodecyl sulfate to pine oil of 1:1-3. However, using this extinguishing agent to extinguish fires involving lithium-ion batteries results in a relatively long extinguishing time. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a composite lithium battery fire extinguishing agent, its preparation method and application, so as to shorten the fire extinguishing time.

[0006] In some embodiments of the present invention, the present invention provides a composite lithium battery fire extinguishing agent, the composite lithium battery fire extinguishing agent comprising: epoxy resin, melamine polyphosphate, ammonium polyphosphate, aluminum silicate cotton, and dispersant.

[0007] When the composite lithium battery fire extinguishing agent of the present invention is used for fire extinguishing, ammonium polyphosphate decomposes upon heating to produce inorganic acids such as phosphoric acid and pyrophosphate. These inorganic acids can undergo esterification with the epoxy groups in epoxy resin, causing the epoxy resin to dehydrate and form char. Melamine polyphosphate decomposes upon heating to produce nitrogen gas and char. Under the action of nitrogen gas and other gases produced during the thermal decomposition of melamine polyphosphate, the char forms a porous carbon layer. This porous carbon layer can prevent heat transfer and oxygen diffusion, thereby further improving the fire extinguishing effect and shortening the fire extinguishing time.

[0008] In some embodiments of the present invention, the composite lithium battery fire extinguishing agent comprises, by weight: 100 parts epoxy resin, 3-5 parts melamine polyphosphate, 1-3 parts ammonium polyphosphate, 1-2 parts aluminum silicate cotton, and 0.5-1 parts dispersant.

[0009] In some embodiments of the present invention, the dispersant comprises a polymer containing acidic groups.

[0010] In some embodiments of the present invention, the diameter of the aluminum silicate cotton is 1-5 μm.

[0011] In some embodiments of the present invention, the composite lithium battery fire extinguishing agent further includes aminated graphene oxide.

[0012] In some embodiments of the present invention, the mass ratio of the aminated graphene oxide to the epoxy resin is 1-3:100, preferably 1.5-2.5:100.

[0013] In this invention, aminated graphene oxide is added to a composite lithium battery fire extinguishing agent. The abundant amino groups on the surface of the aminated graphene oxide can crosslink with the epoxy groups of the epoxy resin to form a dense protective film, further isolating heat and oxygen, thereby further improving the fire extinguishing effect and shortening the fire extinguishing time. If the amount of aminated graphene oxide is too small (mass ratio of aminated graphene oxide to carbon source < 1:100), a dense protective film cannot be formed, and the improvement in fire extinguishing effect is not obvious. If the amount of aminated graphene oxide is too large (mass ratio of aminated graphene oxide to carbon source > 3:100), the dispersion of aminated graphene oxide in the system is poor, resulting in increased defects on the surface of the carbon layer and decreased barrier performance, thus causing poor fire extinguishing effect.

[0014] In some embodiments of the present invention, the composite lithium battery fire extinguishing agent further includes potassium hypochlorite.

[0015] In some embodiments of the present invention, the mass ratio of potassium hypochlorite to epoxy resin is 4-7:100, preferably 4-6:100.

[0016] In this invention, potassium hypochlorite is added to the composite lithium battery fire extinguishing agent. Potassium hypochlorite can increase the char formation rate, thereby improving the fire extinguishing effect and shortening the fire extinguishing time.

[0017] In some embodiments of the present invention, the present invention also provides a method for preparing the composite lithium battery fire extinguishing agent as described above, comprising:

[0018] The composite lithium battery fire extinguishing agent is prepared by mixing the various components.

[0019] In some embodiments of the present invention, this application also provides the application of the composite lithium battery fire extinguishing agent as described above and / or the composite lithium battery fire extinguishing agent prepared according to the preparation method described above in lithium battery fire extinguishing. Detailed Implementation

[0020] The present invention will be further illustrated below through specific examples. However, it should be noted that the specific material ratios, process conditions, and results described in the embodiments of the present invention are only for illustrative purposes and should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention. It should be noted that, unless otherwise specified, all parts mentioned in the present invention refer to parts by weight.

[0021] In some embodiments of the present invention, the present invention provides a composite lithium battery fire extinguishing agent, which, by weight, comprises: 100 parts epoxy resin, 3-5 parts melamine polyphosphate, 1-3 parts ammonium polyphosphate, 1-2 parts aluminum silicate cotton with a diameter of 1-5 μm, and 0.5-1 parts dispersant, wherein the dispersant comprises a polymer containing acidic groups.

[0022] When the composite lithium battery fire extinguishing agent of the present invention is used for fire extinguishing, ammonium polyphosphate decomposes upon heating to produce inorganic acids such as phosphoric acid and pyrophosphate. These inorganic acids can undergo esterification with the epoxy groups in epoxy resin, causing the epoxy resin to dehydrate and form char. Melamine polyphosphate decomposes upon heating to produce nitrogen gas and char. Under the action of nitrogen gas and other gases produced during the thermal decomposition of melamine polyphosphate, the char forms a porous carbon layer. This porous carbon layer can prevent heat transfer and oxygen diffusion, thereby further improving the fire extinguishing effect and shortening the fire extinguishing time.

[0023] In some embodiments of the present invention, the composite lithium battery fire extinguishing agent further includes aminated graphene oxide, wherein the mass ratio of aminated graphene oxide to carbon source is 1-3:100.

[0024] In this invention, aminated graphene oxide is added to a composite lithium battery fire extinguishing agent. The abundant amino groups on the surface of the aminated graphene oxide can crosslink with the epoxy groups of the epoxy resin to form a dense protective film, further isolating heat and oxygen, thereby further improving the fire extinguishing effect and shortening the fire extinguishing time. If the amount of aminated graphene oxide is too small (mass ratio of aminated graphene oxide to carbon source < 1:100), a dense protective film cannot be formed, and the improvement in fire extinguishing effect is not obvious. If the amount of aminated graphene oxide is too large (mass ratio of aminated graphene oxide to carbon source > 3:100), the dispersion of aminated graphene oxide in the system is poor, resulting in increased defects on the surface of the carbon layer and decreased barrier performance, thus causing poor fire extinguishing effect.

[0025] In some embodiments of the present invention, the composite lithium battery fire extinguishing agent further includes potassium hypochlorite, wherein the mass ratio of potassium hypochlorite to carbon source is 4-7:100.

[0026] In this invention, potassium hypochlorite is added to the composite lithium battery fire extinguishing agent. Potassium hypochlorite can increase the char formation rate, thereby improving the fire extinguishing effect and shortening the fire extinguishing time.

[0027] In some embodiments of the present invention, the present invention also provides a method for preparing the composite lithium battery fire extinguishing agent as described above, comprising:

[0028] A composite lithium battery fire extinguishing agent was prepared by mixing carbon source, ammonium phosphate and melamine.

[0029] In some embodiments of the present invention, this application also provides the application of the composite lithium battery fire extinguishing agent as described above and / or the composite lithium battery fire extinguishing agent prepared according to the preparation method described above in lithium battery fire extinguishing.

[0030] The present invention will be described in detail below through specific examples and embodiments. It should also be understood that the following embodiments are only for specific illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0031] Example 1

[0032] A composite lithium battery fire extinguishing agent, which is specifically prepared from the following raw materials according to the following steps:

[0033] Add 5 parts of melamine polyphosphate, 1 part of ammonium polyphosphate, 2 parts of aluminum silicate cotton with a diameter of 3 μm and 0.5 parts of dispersant BYK-W996 to 100 parts of epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0034] Example 2

[0035] A composite lithium battery fire extinguishing agent, which is specifically prepared from the following raw materials according to the following steps:

[0036] Add 3 parts melamine polyphosphate, 3 parts ammonium polyphosphate, 1 part aluminum silicate cotton with a diameter of 3 μm and 1 part dispersant BYK-W996 to 100 parts epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0037] Example 3

[0038] A composite lithium battery fire extinguishing agent, which is specifically prepared from the following raw materials according to the following steps:

[0039] Add 4 parts of melamine polyphosphate, 2 parts of ammonium polyphosphate, 1.5 parts of aluminum silicate cotton with a diameter of 3 μm and 0.8 parts of dispersant BYK-W996 to 100 parts of epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0040] Example 4

[0041] A composite lithium battery fire extinguishing agent, which is specifically prepared from the following raw materials according to the following steps:

[0042] Add 4 parts melamine polyphosphate, 2 parts ammonium polyphosphate, 1.5 parts aluminum silicate cotton with a diameter of 3 μm, 2 parts aminated graphene oxide (commercially available), and 0.8 parts dispersant BYK-W996 to 100 parts epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0043] Example 5

[0044] A composite lithium battery fire extinguishing agent, which is specifically prepared from the following raw materials according to the following steps:

[0045] Add 4 parts melamine polyphosphate, 2 parts ammonium polyphosphate, 1.5 parts aluminum silicate cotton with a diameter of 3 μm, 5 parts potassium hypochlorite, and 0.8 parts dispersant BYK-W996 to 100 parts epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0046] Comparative Example 1

[0047] A composite lithium battery fire extinguishing agent, which is specifically prepared from the following raw materials according to the following steps:

[0048] Add 5 parts of melamine polyphosphate, 1 part of ammonium polyphosphate and 0.5 parts of dispersant BYK-W996 to 100 parts of epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0049] Comparative Example 2

[0050] A composite lithium battery fire extinguishing agent, which is specifically prepared from the following raw materials according to the following steps:

[0051] Add 4 parts melamine polyphosphate, 2 parts ammonium polyphosphate, 1.5 parts aluminum silicate cotton with a diameter of 3 μm, 0.5 parts aminated graphene oxide (commercially available), and 0.8 parts dispersant BYK-W996 to 100 parts epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0052] Comparative Example 3

[0053] A composite lithium battery fire extinguishing agent is prepared from the following raw materials according to the following steps:

[0054] Add 4 parts melamine polyphosphate, 2 parts ammonium polyphosphate, 1.5 parts aluminum silicate cotton with a diameter of 3 μm, 4 parts aminated graphene oxide (commercially available), and 0.8 parts dispersant BYK-W996 to 100 parts epoxy resin E44, stir evenly, and a composite lithium battery fire extinguishing agent is prepared.

[0055] Fire extinguishing performance testing

[0056] Fire extinguishing simulation tests were conducted on the composite lithium battery fire extinguishing agents of Examples 1-5 and Comparative Examples 1-3 respectively. The specific steps were as follows: the fire-prone part of the lithium battery of the electric vehicle was sprayed, specifically using 3 3.7V batteries, the spraying distance was no more than 700m, and the package weight was 1kg. The results are shown in Table 1.

[0057] Table 1 Test Results

[0058] Group Firefighting time, s Example 1 22 Example 2 24 Example 3 25 Example 4 17 Example 5 19 Comparative Example 1 35 Comparative Example 2 22 Comparative Example 3 26

[0059] As shown in Table 1, compared with Comparative Example 1, the extinguishing time of the composite lithium battery fire extinguishing agents in Examples 1-5 was significantly shortened. This result indicates that the composite lithium battery fire extinguishing agent of the present invention has excellent fire extinguishing effect. Specifically, during fire extinguishing, the composite lithium battery fire extinguishing agent of the present invention decomposes upon heating to produce inorganic acids such as phosphoric acid and pyrophosphate. These inorganic acids can undergo esterification with the epoxy groups in the epoxy resin, causing the epoxy resin to dehydrate and form charcoal. Melamine polyphosphate decomposes upon heating to produce nitrogen gas and charcoal. Under the action of nitrogen gas and other gases generated during the thermal decomposition of melamine polyphosphate, the charcoal forms a porous carbon layer. This porous carbon layer can prevent heat transfer and oxygen diffusion, thereby further improving the fire extinguishing effect and shortening the extinguishing time.

[0060] Table 1 shows that the extinguishing time of the composite lithium battery fire extinguishing agent in Comparative Example 1 (without aluminum silicate cotton) was 35 seconds, while the extinguishing time of the composite lithium battery fire extinguishing agent in Example 1 (with aluminum silicate cotton) was 22 seconds. That is, compared with Comparative Example 1, the extinguishing time of the composite lithium battery fire extinguishing agent in Example 1 was significantly shortened. This result indicates that aluminum silicate cotton can prevent the porous carbon layer from cracking, thereby improving the extinguishing effect and shortening the extinguishing time.

[0061] As shown in Table 1, the extinguishing time of the composite lithium battery fire extinguishing agent in Example 3 (without added aminated graphene oxide) was 25 seconds, while the extinguishing time of the composite lithium battery fire extinguishing agent in Example 4 (with added aminated graphene oxide) was 17 seconds. That is, compared to Example 3, the extinguishing time of the composite lithium battery fire extinguishing agent in Example 4 was significantly shortened. This result indicates that, in this invention, the abundant amino groups on the surface of aminated graphene oxide can crosslink and form a dense protective film with the epoxy groups of epoxy resin, further isolating heat and oxygen, thereby further improving the fire extinguishing effect and shortening the extinguishing time.

[0062] As shown in Table 1, the fire extinguishing time of the composite lithium battery fire extinguishing agent in Example 4 (where the mass ratio of aminated graphene oxide to epoxy resin in the composite lithium battery fire extinguishing agent is in the range of 1-3:100, specifically 2:100) is 17s, the fire extinguishing time of the composite lithium battery fire extinguishing agent in Comparative Example 2 (where the mass ratio of aminated graphene oxide to epoxy resin is <1:100, specifically 0.5:100) is 22s, and the fire extinguishing time of the composite lithium battery fire extinguishing agent in Comparative Example 3 (where the mass ratio of aminated graphene oxide to epoxy resin is >3:100, specifically 4:100) is 26s. The results indicate that in this invention, if the amount of aminated graphene oxide is too small (mass ratio of aminated graphene oxide to carbon source < 1:100), a dense protective film cannot be formed, and the improvement in fire extinguishing effect is not significant; if the amount of aminated graphene oxide is too large (mass ratio of aminated graphene oxide to carbon source > 3:100), the dispersion of aminated graphene oxide in the system is poor, resulting in an increase in surface defects of the carbon layer and a decrease in barrier performance, thus causing poor fire extinguishing effect.

[0063] As shown in Table 1, the extinguishing time of the composite lithium battery fire extinguishing agent in Example 3 (without potassium hypochlorite) was 25 seconds, while the extinguishing time of the composite lithium battery fire extinguishing agent in Example 5 (with potassium hypochlorite) was 19 seconds. That is, compared to Example 3, the extinguishing time of the composite lithium battery fire extinguishing agent in Example 5 was significantly shortened. This result indicates that in this invention, potassium hypochlorite can increase the charring rate, thereby improving the extinguishing effect and shortening the extinguishing time.

[0064] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A composite lithium battery fire extinguishing agent, characterized in that, The composite lithium battery fire extinguishing agent includes: epoxy resin, melamine polyphosphate, ammonium polyphosphate, aluminum silicate cotton, dispersant and aminated graphene oxide, wherein the mass ratio of aminated graphene oxide to epoxy resin is 1-3:

100.

2. The composite lithium battery fire extinguishing agent as described in claim 1, characterized in that, By weight, the composite lithium battery fire extinguishing agent comprises: 100 parts epoxy resin, 3-5 parts melamine polyphosphate, 1-3 parts ammonium polyphosphate, 1-2 parts aluminum silicate cotton, and 0.5-1 parts dispersant.

3. The composite lithium battery fire extinguishing agent as described in claim 1, characterized in that, The diameter of the aluminum silicate cotton is 1-2 μm.

4. The composite lithium battery fire extinguishing agent as described in claim 1, characterized in that, The dispersant comprises a polymer containing acidic groups.

5. The composite lithium battery fire extinguishing agent as described in claim 1, characterized in that, The composite lithium battery fire extinguishing agent also includes potassium hypochlorite.

6. The composite lithium battery fire extinguishing agent as described in claim 5, characterized in that, The mass ratio of potassium hypochlorite to epoxy resin is 4-7:

100.

7. The method for preparing the composite lithium battery fire extinguishing agent according to any one of claims 1-6, characterized in that, include: The components are mixed to obtain the composite lithium battery fire extinguishing agent.

8. The application of the composite lithium battery fire extinguishing agent according to any one of claims 1-6 and / or the composite lithium battery fire extinguishing agent prepared by the preparation method according to claim 7 in lithium battery fire extinguishing.