Lithium battery fire extinguishing composition as well as preparation method and application thereof

Abstract

The invention provides a lithium battery fire extinguishing composition as well as a preparation method and application thereof. The fire extinguishing composition provided by the invention is prepared from the following raw materials in parts by weight: 1 to 2 parts of sodium lignin sulfonate, 3 to 4 parts of amide monomers, 2 to 4 parts of acrylic acid series monomers, 1.5 to 2 parts of framework supporting materials, 2 to 3 parts of cross-linking agents and 0.2 to 0.3 part of initiators. According to the fire extinguishing composition provided by the invention, the sodium lignin sulfonate and the amide monomer rapidly expand to form a carbon chain under the action of the cross-linking agent and the initiator, and a high polymer material with a three-dimensional space structure is formed through a copolymerization reaction of the acrylate monomer, so that the mechanical property of the product is improved; the skeleton supporting material is added, so that the three-dimensional structure of the high polymer material is more stable, and the flame retardance is improved; finally, a gel material with a stable space structure can be generated, and efficient fire extinguishing can be achieved. The fire extinguishing composition is further prepared into fire extinguishing hydrogel, so that a multi-synergistic fire extinguishing effect on the lithium battery is achieved, and efficient fire extinguishing of the lithium battery can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and in particular to a lithium battery fire extinguishing composition and a preparation method and application thereof. Background Art

[0002] With the continuous advancement of "carbon neutrality" and "carbon peak", the demand for clean energy in all walks of life is increasing rapidly. Lithium-ion batteries have become the focus of clean energy development due to their high energy density, high energy conversion efficiency, long storage and cycle life, etc. However, lithium-ion batteries are prone to thermal runaway under various abuse conditions such as overheating, overcharging, internal and external short circuits, and acupuncture. In other words, lithium-ion batteries may cause thermal runaway due to external abuse during use, transportation, storage, and other processes. Once a lithium-ion battery has thermal runaway, it will cause fire or even explosion accidents.

[0003] Efficient battery fire extinguishing agents are an important guarantee for the safe use of batteries. Currently, common lithium battery fire extinguishing agents mainly include gas fire extinguishing agents and liquid fire extinguishing agents. The gas fire extinguishing agents currently used to extinguish lithium-ion battery fires are mainly halons, nitrogen, carbon dioxide, heptafluoropropane, perfluorohexanone, etc. Gas fire extinguishing agents require a relatively closed application environment and cannot control the occurrence of re-ignition during thermal runaway of the battery system. Water-based fire extinguishing agents have the characteristics of high specific heat capacity and strong isolation and have more efficient fire extinguishing performance, but their water retention and covering capabilities are very limited. A large amount of water can effectively inhibit the spread of thermal runaway of lithium-ion batteries. However, water can only touch the external surface of the battery, and the actual amount of water required to cool the battery is much greater than the theoretical value. Therefore, existing fire extinguishing agents cannot effectively extinguish lithium battery fires.

[0004] The Chinese patent with the announcement number CN111978489B provides a hydrogel for temporarily plugging an oil pipeline, wherein the hydrogel is obtained by grafting, copolymerizing and chemically crosslinking reactants, wherein the reactants include gelatin, water, amide monomers, acrylic monomers, neutralizers, initiators, two-component crosslinkers, thickeners and preservatives, wherein the mass percentages of the various substances in the reactants are: two-component crosslinkers 0.5%-0.8%, initiators 0.1-0.2%; gelatin 1%-2%, amide monomers 2%-3%, acrylic monomers 1.5%-2%, thickeners 0.2%-0.5%, neutralizers 1.5%-2%, preservatives 0.1%-0.3%, and the balance is water. In the patent document, a two-crosslinker is used for chemical crosslinking during the reaction process to make the product structure more stable, and then a surfactant is added to enhance the performance of the product, and finally a high-viscosity and high-strength hydrogel is generated.

[0005] The hydrogels obtained by the above prior art still have technical problems such as high viscosity, poor fluidity, inability to effectively cover the battery to isolate and extinguish fire, and inability to interrupt the battery's thermal runaway to release gas and intensify combustion. Summary of the invention

[0006] The first purpose of the present invention is to overcome the technical problems in the prior art that the battery cannot be effectively covered to isolate and extinguish the fire and interrupt the battery thermal runaway to release gas to intensify the combustion, and provide a fire extinguishing composition, which comprises, by weight, 1-2 parts of sodium lignin sulfonate, 3-4 parts of amide monomers, 2-4 parts of acrylic acid monomers, 1.5-2 parts of skeleton support materials, 2-3 parts of cross-linking agents and 0.2-0.3 parts of initiators.

[0007] In the fire extinguishing composition provided by the present invention, sodium lignin sulfonate and amide monomers can rapidly expand into long carbon chains under the action of a crosslinking agent and an initiator, and can react to form a polymer material with a three-dimensional spatial structure through a copolymerization reaction of acrylate monomers, thereby improving the mechanical properties of the product; by adding a skeleton support material, the three-dimensional structure of the polymer material can be made more stable, thereby improving the flame retardancy; and finally, a gel material with a stable spatial structure can be generated, thereby realizing efficient fire extinguishing, for example, realizing efficient fire extinguishing of lithium batteries.

[0008] In some embodiments of the present invention, the skeleton support material is selected from at least one of montmorillonite and bentonite.

[0009] The present invention adopts the above-mentioned skeleton support material to effectively improve the stability of the three-dimensional structure of the fire extinguishing composition, while increasing the flame retardant properties of the material, thereby structurally providing the fire extinguishing composition with stable and efficient fire extinguishing performance, especially late fire extinguishing performance, to avoid the high temperature released by the battery out of control during the fire extinguishing process, which may destroy the three-dimensional structure of the fire extinguishing composition and cause a decrease in the fire extinguishing agent coverage and isolation performance, re-ignition, etc.

[0010] In some embodiments of the present invention, the acrylic monomer is selected from at least one of acrylic acid and vinyl acetate.

[0011] In some embodiments of the present invention, the acrylic monomer comprises acrylic acid and vinyl acetate in a mass ratio of (2-8):1.

[0012] In some embodiments of the present invention, the raw materials further include 2-3 parts of a neutralizing agent by weight.

[0013] In some embodiments of the present invention, the neutralizing agent is selected from at least one of bicarbonate and sodium hydroxide, preferably a milder bicarbonate, such as at least one of sodium bicarbonate, potassium bicarbonate, calcium bicarbonate, and ammonium bicarbonate.

[0014] The present invention adopts a neutralizing agent, especially a mild bicarbonate as a neutralizing agent, to adjust the pH of the fire extinguishing composition, and can achieve slow and accurate pH adjustment to make the system neutral, thereby avoiding corrosion to the fire extinguishing object, and ensuring the safe use of the fire extinguishing composition, thereby avoiding harm to users due to the pH.

[0015] In some embodiments of the present invention, the raw materials further include 0.1-0.3 parts by weight of a preservative.

[0016] In some embodiments of the present invention, the preservative is selected from at least one of potassium sorbate and parabens.

[0017] The present invention adopts a preservative, which can effectively prolong the shelf life of the fire extinguishing composition.

[0018] In some embodiments of the present invention, the amide monomer is selected from sodium 2-acrylamide-2-methylpropane sulfonate.

[0019] In some embodiments of the present invention, the cross-linking agent is selected from at least one of NN methylenebisacrylamide and N-hydroxymethyl acrylamide.

[0020] In some embodiments of the present invention, the initiator is selected from at least one of ammonium persulfate, potassium persulfate, and hydrogen peroxide.

[0021] The second object of the present invention is to provide a method for preparing the aforementioned fire extinguishing composition, comprising: Step 1: taking sodium lignin sulfonate and amide monomers to prepare a first solution; Step 2: Take acrylic acid and vinyl acetate to prepare a second solution; Step 3: Pour the second solution into the first solution, mix well, add a skeleton support material, a cross-linking agent and an initiator, and carry out a graft copolymerization reaction to obtain a fire extinguishing composition.

[0022] In some embodiments of the present invention, in step 1, sodium lignin sulfonate and amide monomers are stirred and dissolved at 40-60° C.; And / or, in step 2, the acrylic acid and vinyl acetate are dissolved and stirred at 55-70°C; In some embodiments of the present invention, in step 2, after the acrylic acid and vinyl acetate are prepared, a neutralizing agent is added to neutralize the mixture, and the degree of neutralization is 80-90%, to obtain a second solution; And / or, in the step 3, the reaction temperature of the graft copolymerization reaction is 70-80° C., and the reaction time is 0.5-2 h.

[0023] In some embodiments of the present invention, in step 3, after the graft copolymerization reaction is carried out for 1 hour, a preservative is added to obtain a fire extinguishing composition.

[0024] The fire extinguishing composition obtained by the preparation method provided by the present invention is in a gel-like state and has a stable three-dimensional structure. The free water and bound water in its molecular structure provide a flame retardant effect. After the water evaporates, the hydrogel covers the surface of the battery to play the role of insulation and cooling, thereby providing the fire extinguishing composition with stable and efficient fire extinguishing performance from a structural point of view.

[0025] The third object of the present invention is to provide the use of the aforementioned fire extinguishing composition or the fire extinguishing composition obtained by the aforementioned preparation method in the field of batteries, especially lithium batteries.

[0026] The fourth object of the present invention is to provide a fire extinguishing hydrogel for lithium batteries, the raw materials of which include 9-20wt% of the fire extinguishing composition.

[0027] In some embodiments of the present invention, the raw materials of the fire extinguishing hydrogel include 1-2 parts of sodium lignin sulfonate, 3-4 parts of amide monomers, 2-4 parts of acrylic monomers, 1.5-2 parts of skeleton support materials, 2-3 parts of cross-linking agents, 0.2-0.3 parts of initiators, 2-3 parts of neutralizers, 0.1-0.3 parts of preservatives and water; preferably, the total weight of the raw materials is 100 parts.

[0028] The fire extinguishing hydrogel provided by the present invention is insoluble in water but its molecular structure can absorb a large amount of water; during the fire extinguishing process, the evaporation of water in its structure can absorb a large amount of heat, effectively reducing the temperature of the battery surface; at the same time, the fire extinguishing hydrogel provided by the present invention has the characteristics of strong water retention and high adhesion. During the fire extinguishing process, the volume of the fire extinguishing composition is reduced while it can adhere to the battery surface to form carbon deposits, thereby achieving the effect of isolating air and blocking combustion, and preventing re-ignition; during the synthesis process, sulfonic acid groups are introduced into both the raw materials and the copolymer products, and the sulfonyl free radicals generated by cracking after being heated are very active, and can quickly combine with the hydroxyl free radicals released during the battery combustion process, thereby terminating the chain reaction, thereby achieving the fire extinguishing hydrogel provided by the present invention to play a multiple synergistic fire extinguishing effect on the lithium battery, and realizing efficient fire extinguishing of the lithium battery. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the specific embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Existing fire extinguishing agents cannot effectively extinguish lithium battery fires. Therefore, based on the fire extinguishing composition provided in the invention content section of the present invention, the embodiment section of the present invention provides a fire extinguishing hydrogel for lithium batteries. The raw materials include, by weight: 1-2 parts of sodium lignin sulfonate, 3-4 parts of amide monomers, 2-3 parts of acrylic acid, 0.4-0.7 parts of vinyl acetate, 1.5-2 parts of skeleton support material, 0.5-0.8 parts of cross-linking agent, 0.2-0.3 parts of initiator, 2-3 parts of neutralizer, 0.1-0.3 parts of preservative, and the balance is water. The sum of the weight parts of each substance is 100 parts, that is, the above raw materials by weight can also be expressed as mass percentage, which is explained below in terms of weight percentage.

[0031] The preparation process of the fire extinguishing hydrogel is as follows: Step 1, stirring and dissolving 1%-2% by mass of sodium lignin sulfonate and 3%-4% by mass of amide monomer at 40-60° C. to obtain a first solution; Step 2, dissolving 2%-3% acrylic acid and 0.4%-0.7% vinyl acetate at 55-70° C. with stirring, and adding sodium bicarbonate for neutralization with a neutralization degree of 80-90%, to obtain a second solution; Step 3, pour the second solution into the first solution, stir and mix, add 1.5%-2% of skeleton support material, 0.5%-0.8% of cross-linking agent and 0.2-0.3% of initiator, and carry out graft copolymerization at 70-80°C; after reacting for 1 hour, add 0.1%-0.3% of preservative to obtain hydrogel.

[0032] Among them, the amide monomer is selected from sodium 2-acrylamide-2-methylpropane sulfonate; the acrylic monomer is selected from acrylic acid and vinyl acetate; the skeleton support material is selected from montmorillonite and bentonite; the cross-linking agent is selected from NN methylenebisacrylamide and N-hydroxymethylacrylamide; the initiator is selected from ammonium persulfate, potassium persulfate, and hydrogen peroxide; the neutralizer is selected from bicarbonate (such as sodium bicarbonate, potassium bicarbonate, calcium bicarbonate and ammonium bicarbonate), sodium hydroxide; the preservative is selected from potassium sorbate and parabens.

[0033] All chemical raw materials involved in the present invention are chemically pure and purchased from Sinopharm Chemical Reagent Co., Ltd.; bentonite and montmorillonite used as skeleton support materials are purchased from MacLean Biochemical Technology Co., Ltd.

[0034] The following is a further description with reference to specific embodiments.

[0035] Example 1 The present embodiment provides a fire extinguishing composition, the raw material ratio of which is: 10g sodium lignin sulfonate, 30g amide monomer, 20g acrylic acid, 7g vinyl acetate, 15g skeleton support material bentonite, 5g cross-linking agent, 2g initiator ammonium persulfate, 2g neutralizer sodium bicarbonate, 1g preservative potassium sorbate, and 890g water.

[0036] This embodiment also provides a method for preparing the fire extinguishing composition, the steps are as follows: 1. Add sodium lignin sulfonate and amide monomers to a portion of water, stir and dissolve at 40-60° C. to obtain a first solution; 2. Add acrylic acid and vinyl acetate to another portion of water, stir and dissolve at 55-70° C., and after the acrylic acid and vinyl acetate are completely dissolved, add sodium bicarbonate to neutralize them with a neutralization degree of 80-90%, to obtain a second solution; 3. Pour the second solution into the first solution and stir to mix, add the skeleton support material, the crosslinking agent and the initiator, and carry out the graft copolymerization reaction at 70-80° C.; after reacting for 1 hour, add the preservative to obtain the hydrogel.

[0037] Example 2 This embodiment provides a fire extinguishing composition, which is basically the same as that of Embodiment 1, except that 20 g of acrylic acid and 7 g of vinyl acetate are replaced by 27 g of acrylic acid.

[0038] Comparative Example 1 This comparative example provides a fire extinguishing hydrogel, which is basically the same as Example 1, except that no skeleton support material is added and it is replaced by an equal mass of water.

[0039] Comparative Example 2 This comparative example provides a fire extinguishing hydrogel, which is basically the same as Example 1, except that the cross-linking agent is replaced by a two-component cross-linking agent, and no skeleton support material is added. Specifically, the cross-linking agent uses 0.3g N-N-methylenebisacrylamide and 0.2g N-hydroxymethylacrylamide.

[0040] Test example Test object: the fire extinguishing hydrogels obtained in the embodiments and comparative examples of the present invention.

[0041] Test method: In order to verify the performance of the fire extinguishing agent, a cylindrical lithium-ion-graphite battery with a diameter of 18 mm and a height of 65 mm was selected for a thermal runaway fire extinguishing experiment. The battery capacity was 3Ah and the nominal voltage was 4.2V. First, the battery was fully charged and discharged multiple times using a charging device, and then the battery was charged to 100% of the charge state for the experiment. In the experiment, the fire extinguishing performance of the blank group, fine water mist, perfluorohexanone and the fire extinguishing hydrogels obtained in the embodiments of the present invention and the comparative examples were compared. During the experiment, once the battery safety valve was observed to be open, the heating rod was turned off and the battery heating was stopped. When a jet fire occurred in the battery afterwards, the fire extinguishing agent was immediately released to extinguish the battery fire.

[0042] Experimental results: The data obtained during the test are shown in Table 1.

[0043] Table 1 Fire extinguishing data of different fire extinguishing agents

[0044] It can be seen from Table 1 that the fire extinguishing hydrogel provided by the present invention can extinguish the fire of the lithium battery in a shorter time and can reduce the surface temperature of the battery; at the same time, the surface temperature of the battery after the fire extinguishing hydrogel is extinguished is also lower, and the maximum temperature drop rate is the highest, indicating that the hydrogel has a good cooling and fire extinguishing effect in the fire extinguishing process. The above test data proves that the fire extinguishing hydrogel provided by the present invention is safer to use and has a better fire extinguishing effect.

[0045] The only difference between Example 1 and Comparative Example 1 is that no skeleton support material is added in Comparative Example 1, and the difference between Example 1 and Comparative Example 2 is that the skeleton support material is replaced by a two-component cross-linking agent (0.3 g N-N-methylenebisacrylamide and 0.2 g N-hydroxymethylacrylamide) in the prior art. In contrast, the fire extinguishing hydrogel obtained in Example 1 has better fire extinguishing performance, which is specifically reflected in a shorter fire extinguishing time and a faster drop in the maximum temperature (1.92°C / s faster than Comparative Example 1 and 2.01°C / s faster than Comparative Example 2), indicating that the addition of a skeleton support material can provide the fire extinguishing hydrogel with more efficient fire extinguishing performance, and the addition of a skeleton support material can significantly improve the fire extinguishing efficiency compared with the use of a two-component cross-linking agent in the prior art; at the same time, the fire extinguishing hydrogel obtained in Example 1 also has a lower maximum temperature after the thermal runaway battery is extinguished (43°C lower than Comparative Example 1 and 32°C lower than Comparative Example 2) and a lower temperature after the release of the fire extinguishing agent (57.3°C lower than Comparative Example 1 and 60.1°C lower than Comparative Example 2), indicating that the addition of a skeleton support material increases the flame retardant properties of the material, and the addition of a skeleton support material can significantly improve the flame retardant properties compared with the use of a two-component cross-linking agent in the prior art; and all of this is due to the addition of the skeleton support material giving the fire extinguishing hydrogel a stable three-dimensional structure.

[0046] In other embodiments of the present invention, when preparing the fire extinguishing composition, it is not necessary to add a neutralizing agent and / or a mildew inhibitor, and they can be replaced with an equal amount of water. Among them, the neutralizing agent is used to adjust the pH of the fire extinguishing composition to prevent it from corroding the fire extinguishing object, and to ensure the safe use of the fire extinguishing composition to avoid harm to the user due to the pH. Therefore, even if the embodiments of the present invention do not provide relevant embodiments, those skilled in the art can also expect that the obtained hydrogel fire extinguishing agent can also achieve stable fire extinguishing performance without adding a neutralizing agent. Similarly, even if the embodiments of the present invention do not provide relevant embodiments without adding a mildew inhibitor, those skilled in the art can also expect that the obtained hydrogel fire extinguishing agent can also achieve stable fire extinguishing performance without adding a mildew inhibitor.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fire extinguishing composition, characterized in that: The raw materials include 1-2 parts of sodium lignin sulfonate, 3-4 parts of amide monomers, 2-4 parts of acrylic acid monomers, 1.5-2 parts of skeleton support materials, 2-3 parts of cross-linking agents and 0.2-0.3 parts of initiators by weight.

2. The fire extinguishing composition according to claim 1, characterized in that: The skeleton support material is selected from at least one of montmorillonite and bentonite.

3. The fire extinguishing composition according to claim 1 or 2, characterized in that: The acrylic monomer is selected from at least one of acrylic acid and vinyl acetate; Preferably, the acrylic monomer comprises acrylic acid and vinyl acetate in a mass ratio of (2-8):

1.

4. The fire extinguishing composition according to any one of claims 1 to 3, characterized in that: The raw materials also include 2-3 parts of a neutralizing agent by weight; Preferably, the neutralizing agent is selected from at least one of bicarbonate and sodium hydroxide; Preferably, the bicarbonate is selected from at least one of potassium bicarbonate, sodium bicarbonate, calcium bicarbonate and ammonium bicarbonate.

5. The fire extinguishing composition according to any one of claims 1 to 4, characterized in that: The raw materials also include 0.1-0.3 parts of preservatives by weight; Preferably, the preservative is selected from at least one of potassium sorbate and parabens.

6. The fire extinguishing composition according to any one of claims 1 to 5, characterized in that: The amide monomer includes sodium 2-acrylamide-2-methylpropane sulfonate; And / or, the cross-linking agent is selected from at least one of NN methylenebisacrylamide and N-hydroxymethyl acrylamide; And / or, the initiator is selected from at least one of ammonium persulfate, potassium persulfate and hydrogen peroxide.

7. The method for preparing the fire extinguishing composition according to any one of claims 1 to 6, characterized in that: include: Step 1: taking sodium lignin sulfonate and amide monomers to prepare a first solution; Step 2: Take acrylic acid and vinyl acetate to prepare a second solution; Step 3: Pour the second solution into the first solution, mix well, add a skeleton support material, a cross-linking agent and an initiator, and carry out a graft copolymerization reaction to obtain a fire extinguishing composition.

8. The method for preparing the fire extinguishing composition according to claim 7, characterized in that: In the step 1, sodium lignin sulfonate and amide monomers are dissolved at 40-60° C. to obtain the first solution; And / or, in step 2, the acrylic acid and vinyl acetate are dissolved at 55-70°C; And / or, in the step 2, after the acrylic acid and vinyl acetate are completely dissolved, a neutralizing agent is added for neutralization, and the neutralization degree is 80-90%, to obtain the second solution; And / or, in step 3, the reaction temperature of the graft copolymerization reaction is 70-80° C., and the reaction time is 0.5-2 h; And / or, in the step 3, after the graft copolymerization reaction is carried out for 1 hour, a preservative is added to obtain a fire extinguishing composition.

9. Use of the fire extinguishing composition according to any one of claims 1 to 6 and / or the fire extinguishing composition prepared by the method according to any one of claims 7 to 8 in the field of batteries, wherein the battery is preferably selected from lithium batteries.

10. A fire extinguishing hydrogel for lithium batteries, characterized in that: The raw materials include 9-20wt% of the fire extinguishing composition according to any one of claims 1-6 and / or the fire extinguishing composition prepared by the method according to any one of claims 7-8.

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