Lithium ion battery fire extinguishing agent and preparation method thereof

Abstract

The application discloses a lithium ion battery fire extinguishing agent and a preparation method thereof, and the raw material of the fire extinguishing agent comprises MIL-96-Al / GO and perfluorohexanone; the preparation process of the MIL-96-Al / GO comprises the following steps: uniformly mixing and dispersing graphene oxide, water and MIL-96-Al, then performing hydrothermal reaction, collecting the solid after cooling, and drying to obtain the MIL-96-Al / GO. The application composites the MIL-96-Al and the graphene oxide to obtain a composite material MIL-96-Al / GO, which can be uniformly dispersed in the perfluorohexanone, directly adsorbs fluorine ions in the perfluorohexanone in a long-term storage process, and solves the problem of corrosiveness of the perfluorohexanone. The composite material can also greatly improve the heat of vaporization of the perfluorohexanone, so that the perfluorohexanone has excellent continuous heat absorption capacity, and the problem of easy rekindling of the lithium ion battery is well solved; and the prepared fire extinguishing agent is an insulating, strong heat-absorbing and non-corrosive high-efficiency fire extinguishing agent.

Description

Technical Field

[0001] This invention relates to the field of materials technology, specifically to a lithium-ion battery fire extinguishing agent and its preparation method. Background Technology

[0002] Lithium-ion batteries possess advantages such as excellent cycle performance, no memory effect, and high specific energy, making them widely used in electric vehicles, electrochemical energy storage, and other electronic products. Currently, my country is the world's largest producer and user of lithium-ion batteries and is vigorously developing lithium-ion battery technology. The large-scale application of lithium-ion batteries is a crucial support for achieving the dual-carbon strategy goals. However, lithium-ion batteries are energetic materials with inherent dangers. Under external pressure, electrical abuse, or thermal abuse, they are prone to thermal runaway, leading to fires or even explosions. This is especially true indoors or within energy storage system containers, where the fire load is high, the danger is significant, and fires are difficult to extinguish.

[0003] Lithium-ion battery fires differ from conventional fires, exhibiting multiple characteristics: rapid ignition, long duration, extremely high combustion temperatures, and the potential to ignite even internal battery modules and other flammable materials, leading to larger fires. Furthermore, they are highly susceptible to reignition. Existing extinguishing agents such as heptafluoropropane and carbon dioxide are ineffective in addressing the reignition problem in lithium-ion battery fires. Water is unsuitable as it can cause secondary hazards. Perfluorohexanone, a widely used extinguishing agent, has some effectiveness against lithium-ion battery fires. However, during long-term storage and release for fire suppression, perfluorohexanone readily produces fluoride ions, which can combine with moisture in the environment to form hydrofluoric acid, causing corrosion. Additionally, perfluorohexanone has a low heat of vaporization and poor cooling performance, making it equally prone to reignition in lithium-ion battery fires.

[0004] One method to address the corrosiveness and poor cooling performance of perfluorohexanone (PFH) is to introduce other additives. For example, Chinese patent application CN113209537A introduces heptafluorocyclopentane to PFH to enhance its cooling performance, and the metal-organic framework N2H-MIL-125(Ti) as an adsorbent for water and HF, thereby improving PFH's corrosion resistance and cooling performance. Similarly, Chinese patent application CN113350730A uses PFH as a fire extinguishing material, introducing other fluorinated organic compounds with high heat of vaporization as cooling materials and alumina as an anti-corrosion material to improve PFH's cooling capacity and corrosion resistance as a lithium-ion battery fire extinguishing agent. All of these patents address the corrosiveness of PFH by introducing different additives and other materials with high heat of vaporization to improve its cooling performance, involving mixtures of three or more substances. The mixture of various substances, including liquids and solids, can affect the flowability and permeability of the extinguishing agent. Furthermore, the interfacial bonding between liquid and solid materials presents a challenge. During long-term storage, solid precipitation and liquid stratification can occur, thus impacting the performance of the extinguishing agent. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to improve the corrosion resistance and cooling performance of perfluorohexanone fire extinguishing agent.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] A lithium-ion battery fire extinguishing agent, the raw materials of which include MIL-96-Al / GO and perfluorohexanone; the preparation process of MIL-96-Al / GO includes the following steps: mixing and dispersing graphene oxide, water and MIL-96-Al evenly, then carrying out a hydrothermal reaction, collecting the solid after cooling, and drying to obtain MIL-96-Al / GO.

[0008] Preferably, the ratio of MIL-96-Al / GO to perfluorohexanone is 5-30 mg: 100 ml.

[0009] Preferably, the MIL-96-Al is prepared by hydrothermal reaction using aluminum nitrate as a metal salt, trimesic acid as a ligand, and water as a solvent.

[0010] Preferably, the ratio of graphene oxide to water is 5-20 mg: 50 ml.

[0011] Preferably, the mass ratio of graphene oxide to MIL-96-Al is 5 to 20:100.

[0012] Preferably, the process of uniformly mixing and dispersing graphene oxide, water, and MIL-96-Al includes ultrasonically dispersing the mixture of graphene oxide and water for 1 to 5 hours, adding MIL-96-Al, and ultrasonically dispersing for 1 to 2 hours.

[0013] Preferably, in the preparation process of MIL-96-Al / GO, the hydrothermal reaction temperature is 100-150°C and the time is 6-12 hours.

[0014] The present invention also proposes a method for preparing the lithium-ion battery fire extinguishing agent, comprising the following steps: mixing MIL-96-Al / GO with perfluorohexanone and stirring, and then ultrasonically treating to obtain the lithium-ion battery fire extinguishing agent.

[0015] Preferably, the stirring is performed at room temperature; the stirring time is greater than or equal to 6 hours.

[0016] Preferably, the ultrasonic treatment time is 1 to 3 hours and the temperature does not exceed 30°C.

[0017] The advantages of this invention are:

[0018] The MIL-96-Al material in this invention is a porous organic framework material with good chemical and thermal stability. By combining it with graphene oxide (GO), a composite material, MIL-96-Al / GO, is obtained. This composite material can be uniformly dispersed in perfluorohexanone (PFH), solving the problem of particle agglomeration in PPH and directly adsorbing fluoride ions during long-term storage of PPH, thus resolving the corrosiveness issue of PPH. Furthermore, the addition of the MIL-96-Al / GO solid material increases the interaction between PPH solvent molecules and MIL-96-Al / GO, thereby enhancing the cohesive force between PPH molecules and significantly increasing the heat of vaporization of PPH. Simultaneously, with the addition of solid particles, the vapor pressure of the PPH solvent decreases, meaning that greater phase transition resistance needs to be overcome during vaporization. Therefore, more energy is required for solvent vaporization, leading to an increase in the heat of vaporization. This gives PPH excellent sustained endothermic capabilities, effectively addressing the problem of easy re-ignition in lithium-ion batteries. The lithium-ion battery fire extinguishing agent prepared by this invention is a highly efficient fire extinguishing agent with strong insulation, heat absorption, and no corrosion, and can be used as a fire extinguishing agent in energized scenarios. Attached Figure Description

[0019] Figure 1 The XRD patterns of MIL-96-Al, GO, and MIL-96-Al / GO in Embodiment 1 of the present invention are shown below.

[0020] Figure 2 This is a SEM image of MIL-96-Al / GO in Embodiment 1 of the present invention;

[0021] Figure 3 The adsorption curve of fluoride ions for MIL-96-Al / GO in Example 1 of this invention is shown.

[0022] Figure 4 This is a schematic diagram of the battery box and battery arrangement used in the performance testing process of this invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0025] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0026] Example 1

[0027] A method for preparing a lithium-ion battery fire extinguishing agent includes the following steps:

[0028] (1) Preparation of MIL-96-Al

[0029] Weigh 3g of aluminum nitrate nonahydrate and 3g of trimesic acid and add them to 50ml of pure water. Stir in a glass beaker until the solids are completely dissolved in the water. Then transfer to a 100ml polytetrafluoroethylene reaction vessel, place it in a drying oven, heat to 250℃ and react for 36 hours. After naturally cooling to room temperature, collect the obtained powder product by centrifugation. Simultaneously, wash the product three times with pure water by centrifugation to remove residual substances. Then transfer it to an 80℃ drying oven and dry for 15 hours to obtain the desired MIL-96-Al.

[0030] (2) Preparation of MIL-96-Al / GO

[0031] Weigh 20 mg of graphene oxide (GO) and dissolve it in 50 ml of pure water. Place the solution in a CNC ultrasonic cleaner and sonicate for 5 hours to ensure complete dispersion of GO in the water. Add 100 mg of the synthesized MIL-96-Al to the solution and continue sonicating for 2 hours to ensure thorough mixing of the MIL-96-Al powder with GO. Transfer the mixture to a 100 ml polytetrafluoroethylene (PTFE) reactor and place it in a drying oven. Heat the oven to 150°C and react for 12 hours. After naturally cooling to room temperature, collect the powder product by centrifugation and transfer it to an 80°C drying oven for 12 hours to obtain the desired MIL-96-Al / GO.

[0032] (3) Preparation of extinguishing agents

[0033] Weigh 24 mg of MIL-96-Al / GO powder and add it to 100 ml of perfluorohexanone in a round-bottom flask. Seal the round-bottom flask with a stopper and stir at room temperature for 10 hours to ensure that the MIL-96-Al / GO powder is evenly dispersed in the perfluorohexanone solution. Then transfer the solution to an ultrasonic cleaner and sonicate for 3 hours. During the sonication process, add ice cubes to the cleaner intermittently to control the water temperature in the cleaner to not exceed 30°C.

[0034] Figure 1 The XRD image shown is of MIL-96-Al / GO prepared in Example 1. Comparing the XRD images with those of MIL-96-Al and GO, the results show that... Figure 1 It can be seen that the three characteristic peaks of GO are in the range of 2θ = 15 to 30. After combining with GO, MIL-96-Al / GO (i.e., MIL-96-Al@GO shown in the figure) shows the characteristic peaks of both MIL-96-Al and GO, indicating that MIL-96-Al and GO have successfully combined.

[0035] pass Figure 2 SEM observation of the overall morphology of MIL-96-Al / GO clearly showed the nanosheet structure of the GO used, in which MIL-96-Al was uniformly dispersed on GO and well bound to GO.

[0036] Example 2

[0037] A method for preparing a lithium-ion battery fire extinguishing agent includes the following steps:

[0038] (1) Preparation of MIL-96-Al

[0039] Weigh 2g of aluminum nitrate nonahydrate and 2g of trimesic acid and add them to 50ml of pure water. Stir in a glass beaker until the solids are completely dissolved in the water. Then transfer to a 100ml polytetrafluoroethylene reaction vessel, place it in a drying oven, heat to 200℃ and react for 24 hours. After naturally cooling to room temperature, collect the obtained powder product by centrifugation. Simultaneously, wash the product three times with pure water by centrifugation to remove residual substances. Then transfer it to a drying oven at 120℃ and dry for 12 hours to obtain the desired MIL-96-Al.

[0040] (2) Preparation of MIL-96-Al / GO

[0041] Weigh 5 mg of graphene oxide (GO) and dissolve it in 50 ml of pure water. Place the solution in a CNC ultrasonic cleaner and ultrasonically vibrate for 3 hours to ensure the GO is fully dispersed in the water. Add 100 mg of the synthesized MIL-96-Al to the solution and continue ultrasonically vibrating for 1 hour to ensure the MIL-96-Al powder is fully mixed with the GO. Transfer the mixture to a 100 ml polytetrafluoroethylene (PTFE) reactor and place it in a drying oven. Heat the oven to 120°C and react for 8 hours. After naturally cooling to room temperature, collect the powder product by centrifugation and transfer it to a 120°C drying oven for 12 hours to obtain the desired MIL-96-Al / GO.

[0042] (3) Preparation of extinguishing agents

[0043] Weigh 16 mg of MIL-96-Al / GO powder and add it to 100 ml of perfluorohexanone in a round-bottom flask. Seal the round-bottom flask with a stopper and stir at room temperature for 6 hours to ensure that the MIL-96-Al / GO powder is evenly dispersed in the perfluorohexanone solution. Then transfer the solution to an ultrasonic cleaner and sonicate for 2 hours. During the sonication process, add ice cubes to the cleaner intermittently to control the water temperature in the cleaner to not exceed 30°C.

[0044] Example 3

[0045] A method for preparing a lithium-ion battery fire extinguishing agent includes the following steps:

[0046] (1) Preparation of MIL-96-Al

[0047] Weigh 2.5g of aluminum nitrate nonahydrate and 2.5g of trimesic acid and add them to 50ml of pure water. Stir in a glass beaker until the solids are completely dissolved in the water. Then transfer to a 100ml polytetrafluoroethylene reaction vessel, place it in a drying oven, heat to 180℃ and react for 12 hours. After naturally cooling to room temperature, collect the obtained powder product by centrifugation. Simultaneously, wash the product three times with pure water by centrifugation to remove residual substances. Then transfer it to a 100℃ drying oven and dry for 12 hours to obtain the desired MIL-96-Al.

[0048] (2) Preparation of MIL-96-Al / GO

[0049] 10 mg of graphene oxide (GO) was dissolved in 50 ml of pure water and ultrasonically vibrated in a CNC ultrasonic cleaner for 1 hour to ensure complete dispersion of GO in the water. 100 mg of the synthesized MIL-96-Al was added to the solution, and ultrasonic vibration continued for 1.5 hours to ensure thorough mixing of the MIL-96-Al powder with GO. The mixture was then transferred to a 100 ml polytetrafluoroethylene (PTFE) reactor, placed in a drying oven, heated to 100°C, and reacted for 6 hours. After natural cooling to room temperature, the obtained powder product was collected by centrifugation and transferred to an 80°C drying oven for 12 hours to obtain the desired MIL-96-Al / GO.

[0050] (3) Preparation of extinguishing agents

[0051] Weigh 8 mg of MIL-96-Al / GO powder and add it to 100 ml of perfluorohexanone in a round-bottom flask. Seal the round-bottom flask with a stopper and stir at room temperature for 8 hours to ensure that the MIL-96-Al / GO powder is evenly dispersed in the perfluorohexanone solution. Then transfer the solution to an ultrasonic cleaner and sonicate for 1 hour. During the sonication process, add ice cubes to the cleaner intermittently to control the water temperature in the cleaner to not exceed 30°C.

[0052] Comparative Example 1

[0053] The difference from Example 1 is that it only includes steps (1) and (3) of Example 1, and in step (3), the fire extinguishing agent is prepared by using the MIL-96-Al prepared in step (1) instead of the MIL-96-Al / GO powder.

[0054] Comparative Example 2

[0055] Preparation of fire extinguishing agents

[0056] Weigh 24 mg of GO powder and add it to 100 ml of perfluorohexanone in a round-bottom flask. Seal the round-bottom flask with a stopper and stir at room temperature for 10 hours to ensure that the GO powder is evenly dispersed in the perfluorohexanone solution. Then transfer the solution to an ultrasonic cleaner and sonicate for 3 hours. During the sonication process, add ice cubes to the cleaner intermittently to control the water temperature in the cleaner to not exceed 30°C.

[0057] Comparative Example 3

[0058] Preparation of fire extinguishing agents

[0059] The difference from Example 1 is that it only includes steps (1) and (3) of Example 1, and in step (3), the mixture of MIL-96-Al and graphene oxide prepared in step (1) is used to replace the MIL-96-Al / GO powder to prepare the fire extinguishing agent, wherein the mass ratio of MIL-96-Al to graphene oxide is 5:1.

[0060] The performance of the extinguishing agents in Examples 1-3 and Comparative Examples 1-3 was tested, and the specific test methods are as follows:

[0061] The extinguishing agent and perfluorohexanone of this invention were manually activated using a handheld fire extinguisher to verify their ability to suppress thermal runaway in lithium batteries. The amount of extinguishing agent used was 1500 ml.

[0062] 1) Type of test cell: Square aluminum-cased lithium iron phosphate battery, 3.2V 280Ah;

[0063] 2) Thermal runaway triggering method: Thermal runaway is triggered by heating.

[0064] 3) Startup method: Manual startup;

[0065] 4) Test chamber: Stainless steel shell, dimensions 840mm long, 335mm wide, and 150mm high (temperature and voltage detectors are installed at the battery cells to record thermal runaway test data), schematic diagram as shown. Figure 4 As shown;

[0066] Table 1 below shows a comparison of the fire extinguishing processes of perfluorohexanone and pure perfluorohexanone fire extinguishing agents under different MIL-96-Al / GO addition amounts in Examples 1-3.

[0067] Table 1

[0068]

[0069] Table 2 Comparison of extinguishing processes of extinguishing agents in Comparative Examples 1-3

[0070] Flame disappearance time / s 12s 6s 7s 9s Did reignition occur? yes yes yes yes Reignition time after the open flame is extinguished 35s 51s 42s 46s

[0071] Table 3 Comparison of the cooling process of perfluorohexanone fire extinguishing agent under different MIL-96-Al / GO addition amounts in Examples 1-3

[0072]

[0073] Table 4 Comparison of the cooling process of extinguishing agents in Comparative Examples 1-3

[0074]

[0075]

[0076] As can be seen from the comparison results in Tables 1-4, with the increase of MIL-96-Al / GO addition, the modified perfluorohexanone significantly improves the extinguishing speed, continuous cooling capacity, and suppression of reignition in lithium-ion battery fires. This fully demonstrates the performance-enhancing effect of MIL-96-Al / GO on perfluorohexanone.

[0077] Meanwhile, to understand the corrosive effect of the extinguishing agent, Q335 steel plate was selected as the observation object. 100g of Q335 steel plate was immersed in perfluorohexanone extinguishing agents with different MIL-96-Al / GO addition amounts for 30 days. The steel plates were then removed, dried, and weighed to observe changes in their mass.

[0078] Table 5. Corrosion resistance of extinguishing agents with different MIL-96-Al / GO addition amounts

[0079]

[0080] As the amount of MIL-96-Al / GO added increases, the mass loss of the steel plate gradually decreases, which fully demonstrates the effect of MIL-96-Al / GO on improving the corrosion resistance of perfluorohexanone.

[0081] Table 6 Physical properties of pure perfluorohexanone and the fire extinguishing agent of Example 1

[0082]

[0083] Adsorption test method for free fluoride ions: According to experimental requirements, a 0.01 mol / L fluoride ion standard solution was prepared using sodium fluoride. 24 mg of the MIL-96-Al / GO powder prepared in Example 1 was weighed and added to 100 ml of the fluoride ion standard solution. After standing for a period of time, a small amount of suspension was taken out and centrifuged at predetermined time intervals to separate the supernatant. The concentration of fluoride ions in the supernatant was measured using a fluoride ion selective electrode, and the data was recorded. The adsorption efficiency of the powder for fluoride ions was calculated, and the results are as follows: Figure 3 As shown, from Figure 3 As can be seen, the MIL-96-Al / GO prepared in this invention has a strong adsorption efficiency for free fluoride ions, with an adsorption efficiency of up to 98% within 100s.

[0084] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lithium-ion battery fire extinguishing agent, characterized in that: Its raw materials include MIL-96-Al / GO and perfluorohexanone; the ratio of MIL-96-Al / GO to perfluorohexanone is 5~30mg:100ml; the preparation process of MIL-96-Al / GO... The process includes the following steps: mixing and dispersing graphene oxide, water, and MIL-96-Al evenly, then carrying out a hydrothermal reaction, collecting the solid after cooling, and drying to obtain the MIL-96-Al / GO; the mass ratio of graphene oxide to MIL-96-Al is 5~20:

100.

2. The lithium-ion battery fire extinguishing agent according to claim 1, characterized in that: The MIL-96-Al is prepared by a hydrothermal reaction using aluminum nitrate as the metal salt, pyromellitic acid as the ligand, and water as the solvent.

3. The lithium-ion battery fire extinguishing agent according to claim 1, characterized in that: The ratio of graphene oxide to water is 5~20 mg: 50 ml.

4. The lithium-ion battery fire extinguishing agent according to claim 1, characterized in that: The process of uniformly mixing and dispersing graphene oxide, water, and MIL-96-Al includes ultrasonically dispersing the graphene oxide and water mixture for 1-5 hours, adding MIL-96-Al, and ultrasonically dispersing for 1-2 hours.

5. The lithium-ion battery fire extinguishing agent according to any one of claims 1-4, characterized in that: In the preparation process of MIL-96-Al / GO, the hydrothermal reaction temperature is 100~150℃ and the time is 6~12h.

6. A method for preparing a lithium-ion battery fire extinguishing agent as described in any one of claims 1-5, characterized in that: Includes the following steps: The lithium-ion battery fire extinguishing agent was obtained by mixing MIL-96-Al / GO with perfluorohexanone, stirring, and then ultrasonic treatment.

7. The method for preparing the lithium-ion battery fire extinguishing agent according to claim 6, characterized in that: The stirring is carried out at room temperature; the stirring time is greater than or equal to 6 hours.

8. The method for preparing the lithium-ion battery fire extinguishing agent according to claim 6 or 7, characterized in that: The ultrasonic treatment lasts for 1 to 3 hours, and the temperature does not exceed 30°C.

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