High-permeability fast-spreading fire extinguishing gel and preparation method and application thereof

Abstract

The application belongs to the technical field of fire safety, and relates to a high-permeability and fast-spreading fire extinguishing gel as well as a preparation method and application thereof. Raw materials of the fire extinguishing gel include a gelling agent, a thickening agent, a surfactant, a crosslinking agent, a fire retardant and an antifreezing agent. The gelling agent is hydroxypropyl cellulose, the thickening agent is hydroxypropyl chitosan, and the surfactant is a JFC type surfactant. The mass ratio of the JFC type surfactant to the hydroxypropyl chitosan is 1:1-1.5. The application adopts hydroxypropyl cellulose as a temperature response gelling agent, cooperates with hydroxypropyl chitosan and a magnesium salt crosslinking agent to construct a response system, forms an intelligent response mechanism, can quickly intervene at the initial stage of thermal runaway of a lithium battery, ensures the durability and reliability of fire extinguishing, and effectively inhibits heat spread. Through introduction of a JFC type surfactant and hydroxypropyl chitosan rheological regulation technology, intelligent response of gelation after contacting the surface of a high-temperature lithium battery under normal temperature is realized, with low viscosity and high flowability.

Description

Technical Field

[0001] This invention belongs to the field of fire safety technology, and relates to a high-penetration, rapidly spreading lithium battery thermal runaway extinguishing gel, its preparation method, and its application. Background Technology

[0002] With the deepening of the "dual carbon" goals and the rapid development of the new energy industry, lithium-ion batteries, with their advantages of high energy density, long cycle life, and low self-discharge rate, have been widely used in electric vehicles, electrochemical energy storage systems, portable electronic devices, and other fields. However, lithium-ion batteries are highly susceptible to thermal runaway under abuse conditions such as overcharging, internal short circuits, mechanical damage, or overheating, leading to violent combustion or even explosions. Lithium battery fires are characterized by high combustion temperatures (up to 1000℃ or higher), rapid spread, easy reignition, and the release of large amounts of toxic gases (such as hydrogen fluoride and carbon monoxide). They also involve Class A, B, and C fires, making them difficult to effectively combat using traditional fire extinguishing methods.

[0003] In recent years, hydrogel fire extinguishing materials have become a research hotspot in the field of lithium battery fire extinguishing due to their high water content, good adhesion and coverage, and excellent cooling effect. Hydrogels are systems with a three-dimensional network structure formed by combining one or more polymers with water. They can block oxygen supply through physical barriers, while utilizing the high latent heat of vaporization of water for continuous cooling, effectively inhibiting combustion reactions and heat spread. Currently, various hydrogel fire extinguishing agents have been developed and applied to different fire scenarios: Chinese invention patent CN120000989A discloses a temperature-sensitive hydrogel that is easy to transport at low temperatures and has significantly increased viscosity at high temperatures, which is beneficial for adhesion to the surface of combustible materials. Chinese invention patent CN113069707A discloses a hydrogel fire extinguishing agent that combines the fluidity of water-based fire extinguishing agents with the adhesiveness of gel fire extinguishing agents, effectively penetrating into the interior of lithium batteries.

[0004] However, existing thermosensitive hydrogel fire extinguishing agents still have many shortcomings when applied to lithium battery thermal runaway fires. First, existing hydrogels generally suffer from excessive viscosity, making spraying difficult. Furthermore, their high surface tension limits their penetration and spreading capabilities, preventing them from effectively penetrating the tiny gaps between battery modules (typically less than 1 mm) and reaching the core of the thermal runaway, resulting in incomplete extinguishing and a high reignition rate. Second, thermosensitive hydrogels suitable for Class A fires are primarily designed for solid combustibles, making them unsuitable for the rapid suppression of high-energy fire sources such as lithium-ion battery fires. They also exhibit significant shortcomings in heat resistance, structural strength, and environmental adaptability. In addition, existing hydrogel fire extinguishing agent formulations often contain multiple complex polymer materials, leading to complex preparation processes, high costs, and poor stability during long-term storage, limiting their flexibility in practical deployment.

[0005] In summary, while existing temperature-sensitive hydrogels each possess certain fire extinguishing potential, they generally suffer from insufficient penetration and spreading ability, slow response speed, poor thermal stability, and high usage costs, making it difficult to meet the demands for rapid, efficient, and safe fire extinguishing in lithium battery thermal runaway fires. Therefore, there is an urgent need to develop a novel lithium battery thermal runaway fire extinguishing gel with high penetration and rapid spreading characteristics, while also exhibiting excellent cooling effects, good thermal stability, and environmental friendliness, to address the aforementioned shortcomings of existing technologies. Summary of the Invention

[0006] The main objective of this invention is to overcome the problems existing in the fire extinguishing application of lithium-ion batteries, such as insufficient penetration and spreading ability, slow response speed, poor thermal stability, limited cooling effect, high reignition rate, high preparation cost, poor storage stability, and insufficient environmental friendliness. This invention provides a high-penetration, rapid-spreading lithium battery thermal runaway fire extinguishing gel, its preparation method, and its application, which realizes rapid, efficient, safe, and green fire extinguishing of lithium battery thermal runaway fires, and has important application prospects and industrial promotion value.

[0007] To achieve the above objectives, the specific technical solution is as follows: This invention provides a highly penetrating and rapidly spreadable fire extinguishing gel, the raw materials of which include a gelling agent, a thickener, a surfactant, a crosslinking agent, a flame retardant, and an antifreeze agent; The gelling agent is hydroxypropyl cellulose, the thickener is hydroxypropyl chitosan, and the surfactant is a JFC-type surfactant; the mass ratio of the JFC-type surfactant to the hydroxypropyl chitosan is 1:1 to 1.5.

[0008] The fire extinguishing gel of this invention uses hydroxypropyl cellulose, which has thermosensitive phase change properties. It forms a dense gel when exposed to high temperatures, giving the system core temperature-responsive gel properties. Upon contact with the surface of a high-temperature lithium battery, it undergoes a phase change to form a dense three-dimensional network structure. Hydroxypropyl chitosan is used to construct the basic three-dimensional structure of the hydrogel and adjust the rheological properties of the system. JFC-type surfactant (branched fatty alcohol polyoxyethylene ether, RO(CH2CH2O)) is also used. n H and R are C8-C10 branched alkyl groups, and n is 4-8) to reduce the surface tension of the gel, improve wettability and penetration, and enable the fire extinguishing gel to spread rapidly on the battery surface.

[0009] This invention constructs a highly effective synergistic functional system by compounding JFC-type surfactants and hydroxypropyl chitosan at a mass ratio of 1:1 to 1.5. Within this specific dosage range, the two achieve optimal coupling of rheological regulation and permeability, overcoming the bottlenecks of excessive viscosity and insufficient permeability and spreading ability of traditional hydrogels. It achieves a smart response of low viscosity and high fluidity at room temperature and gelation upon contact with the surface of high-temperature lithium batteries, enabling rapid penetration of tiny gaps less than 2 mm in the battery module and complete coverage of the core area of ​​internal thermal runaway. Simultaneously, through continuous cooling, a dense three-dimensional network structure is formed to cover the fire source, achieving efficient suppression and thermal insulation of the flame, effectively interrupting the combustion chain reaction, efficiently extinguishing lithium battery fires and inhibiting reignition.

[0010] Furthermore, the fire extinguishing gel comprises the following components in parts by weight: Hydroxypropyl cellulose (HPC) 1 to 3 parts, hydroxypropyl chitosan 3 to 4.5 parts, JFC type surfactant 2 to 3 parts, crosslinking agent 2 to 5 parts, flame retardant 2 to 6 parts, antifreeze 3 to 5 parts.

[0011] The fire extinguishing gel of this invention uses the above-mentioned amount of hydroxypropyl cellulose, the concentration of which takes into account both room temperature fluidity and high temperature insulation and cooling effect. Through the synergistic effect of the above-mentioned material components, the fire extinguishing gel has high penetration and rapid spreading characteristics, rapid response capability, excellent high temperature stability and long-lasting cooling effect. It is a fire extinguishing gel for lithium battery thermal runaway, used for rapid extinguishing and continuous thermal runaway suppression and control of fires caused by thermal runaway of lithium-ion battery cells, modules and battery packs.

[0012] Furthermore, the JFC-type surfactant is a JFC-3 type surfactant.

[0013] Furthermore, the crosslinking agent is selected from one or both of magnesium chloride and magnesium nitrate.

[0014] This invention uses magnesium chloride and magnesium nitrate as crosslinking agents, which can assist in crosslinking to enhance the high-temperature structural strength of hydrogels and synergistically improve pH response sensitivity.

[0015] Furthermore, the flame retardant is selected from diammonium hydrogen phosphate (DAP).

[0016] This invention uses diammonium hydrogen phosphate as a flame retardant to interrupt the combustion chain reaction and, in conjunction with physical barrier effects, inhibit the reignition of lithium batteries.

[0017] Furthermore, the antifreeze is composed of propylene glycol (PG) and glycerin in a mass ratio of 1 to 2:1.

[0018] This invention employs a composite antifreeze system made by compounding propylene glycol (PG) and glycerin in a specific mass ratio, significantly expanding the product's low-temperature application range. It ensures normal operation within a wide temperature range of -20℃ to 60℃, adapting to different regional climate conditions. It can be widely applied in various complex working conditions and locations, such as new energy vehicle power battery packs, electrochemical energy storage power stations, large energy storage containers, power battery dismantling workshops, and portable electronic device warehouses, for emergency handling and thermal runaway prevention of lithium battery fires.

[0019] Furthermore, the fire extinguishing gel also includes 1 to 3 parts of a moisturizing rheology modifier, preferably dipropylene glycol (DPG).

[0020] This invention uses dipropylene glycol (DPG) as a moisturizing rheology modifier to improve the moisturizing performance of the gel system, optimize its rheological properties, and help lower the freezing point of the system.

[0021] Preferably, the fire extinguishing gel is composed of the following components by mass percentage: The composition includes 1.5%-2% hydroxypropyl cellulose, 3%-4.5% hydroxypropyl chitosan, 3.0%-3.5% magnesium chloride or magnesium nitrate, 1.5%-2% dipropylene glycol, 1.5%-3% JFC-type surfactant, 4%-5% diammonium hydrogen phosphate, 3.5%-4% composite antifreeze, with the balance being deionized water; the composite antifreeze is composed of propylene glycol and glycerin in a mass ratio of 1-1.5:1.

[0022] The present invention also provides a method for preparing the above-mentioned fire extinguishing gel, comprising the following steps: (1) Dissolve hydroxypropyl cellulose and hydroxypropyl chitosan in deionized water respectively, let stand to defoam, and obtain hydroxypropyl cellulose solution and hydroxypropyl chitosan solution; (2) The hydroxypropyl cellulose solution, hydroxypropyl chitosan solution and crosslinking agent are stirred and mixed to obtain a mixed solution; (3) The moisturizing rheology modifier, surfactant, flame retardant, and antifreeze are stirred and mixed with the mixed solution, allowed to stand to defoam, dried into block solid, and then crushed to obtain powdered fire extinguishing gel.

[0023] The fire extinguishing gel prepared by this invention is in powder form, possessing good storage stability and convenient transportation, with a shelf life of over 2 years. This significantly expands its application possibilities in various scenarios such as new energy vehicles and electrochemical energy storage power stations.

[0024] Preferably, the hydroxypropyl cellulose and the hydroxypropyl chitosan are placed in an oven at 65-75°C and dried for 1-2 hours, then removed and cooled to room temperature in a vacuum drying oven for later use.

[0025] Further, in step (1), the hydroxypropyl cellulose is dissolved in deionized water at a temperature of 55-65°C and a rotation speed of 300-500 r / min for 1-2 hours, and then left to stand for 20-24 hours.

[0026] Further, in step (2), the hydroxypropyl chitosan is dissolved in deionized water at a temperature of 60-70°C and a rotation speed of 400-600 r / min for 1-2 hours, and then left to stand for 20-24 hours.

[0027] Furthermore, in steps (3) and (4), the stirring speed is 500-700 r / min and the stirring time is 1-2 h; in step (4), the settling time is 12-24 h.

[0028] Furthermore, in step (4), the drying is carried out under vacuum conditions at 60-70°C; preferably, the powder is sieved through a 100-mesh sieve after pulverization.

[0029] The present invention also provides a hydrogel fire extinguishing agent, comprising the above-mentioned fire extinguishing gel; preferably, the fire extinguishing gel is 2% to 5% of the mass of the hydrogel fire extinguishing agent.

[0030] When using the fire extinguishing gel of this invention, 2% to 5% by mass of the above-mentioned powdered fire extinguishing gel is added to deionized water and stirred evenly to obtain a fire extinguishing agent specifically for lithium-ion batteries that can be used directly. The functional components in the formula work synergistically, and the fire extinguishing gel can form a fire extinguishing colloid at a mass concentration of 2% to 5%, significantly improving water-based fire extinguishing capabilities. It eliminates the need for complex on-site preparation equipment, simplifies on-site operation procedures, and greatly improves emergency response efficiency.

[0031] Compared with the prior art, the present invention has the following significant advantages: This invention uses hydroxypropyl cellulose (HPC) as a temperature-responsive gelling agent, combined with hydroxypropyl chitosan and magnesium salt crosslinking agent to construct a response system, forming an intelligent response mechanism. Compared with traditional temperature-sensitive gels, the gel of this invention can quickly intervene in the early stage of lithium battery thermal runaway, and can still maintain structural integrity in extreme high temperature environments above 1000℃, ensuring the durability and reliability of fire extinguishing effect and effectively inhibiting heat spread.

[0032] This invention introduces JFC-type high-penetration surfactant and hydroxypropyl chitosan rheology regulation technology to achieve a smart response with low viscosity and high fluidity at room temperature and gelation upon contact with the surface of a high-temperature lithium battery, thus solving the problem that traditional fire extinguishing agents have difficulty reaching the internal fire source and are incomplete in extinguishing fires.

[0033] The three-dimensional network structure of the fire extinguishing gel of this invention can lock in a large amount of water, and use the high latent heat of vaporization of water to achieve continuous and deep cooling of lithium batteries, fundamentally interrupting the chain exothermic reaction inside the battery; at the same time, in combination with the chemical inhibition effect of diammonium hydrogen phosphate (DAP) flame retardant, the dual mechanism works synergistically to significantly reduce the battery temperature and reduce the reignition rate to below 10%, which is far superior to traditional fire extinguishing agents.

[0034] The raw materials used in this invention are all low-toxicity or non-toxic, biodegradable materials. Hydroxypropyl cellulose and hydroxypropyl chitosan are both natural modified polymer materials, diammonium hydrogen phosphate (DAP) is a low-toxicity and environmentally friendly flame retardant, and propylene glycol and glycerin are both food-grade safety additives. The formula does not contain perfluorinated compounds, heavy metals, or other harmful substances, avoiding the problem of traditional fire extinguishing agents decomposing and releasing toxic and harmful gases at high temperatures. This significantly reduces the harm to the environment and human health, and leaves no residue after extinguishing the fire, making it easy to clean and preventing secondary damage to batteries and surrounding equipment. Furthermore, the raw materials used are all industrial-grade and readily available products, the preparation process is simple, and it has good economic efficiency and promotional value. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0036] Figure 1 This is the fire-fighting experiment temperature curve of Example 1 of the present invention; Figure 2 This is the temperature curve of the fire-fighting experiment applied in Comparative Example 1 of this invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] The terms "preferred," "further preferred," and "more preferred" used in this invention, followed by technical features, constitute preferred embodiments of the invention in a specific aspect, but should not be construed as limiting the scope of protection. When the preferred definitions at each level are combined in a progressive relationship, the degree of preference increases progressively.

[0039] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0040] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0041] The technical solution of the present invention will be described in detail below through embodiments and comparative examples. It should be noted that the following embodiments are only used to help understand the technical solution of the present invention and do not constitute any limitation on the scope of protection of the present invention.

[0042] Unless otherwise specified, specific techniques or conditions in the embodiments of this invention shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Devices, instruments, reagents, etc., whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels. All raw materials used in this invention are readily available in the domestic market.

[0043] Example 1 This embodiment provides a fire extinguishing gel and its preparation method. The fire extinguishing gel is composed of the following components by mass percentage: The composition includes 2% hydroxypropyl cellulose (HPC), 3% hydroxypropyl chitosan, 3.5% magnesium chloride (crosslinking agent), 2% dipropylene glycol (DPG), 2% JFC-3 type surfactant, 4% diammonium hydrogen phosphate (DAP) (flame retardant), 4% composite antifreeze, and the balance being deionized water; the composite antifreeze is composed of propylene glycol and glycerol in a mass ratio of 1.5:1.

[0044] The steps of the preparation method of the fire extinguishing gel in this embodiment are as follows: (1) Place hydroxypropyl cellulose and hydroxypropyl chitosan in an oven at 70°C and dry for 1.5 hours. After drying, place them in a vacuum drying oven and cool to room temperature for later use. (2) Hydroxypropyl cellulose was added to deionized water at 60°C and stirred at 400 r / min for 1.5 hours to dissolve it. The solution was then allowed to stand at room temperature for 24 hours to remove bubbles and obtain a hydroxypropyl cellulose solution. (3) Add hydroxypropyl chitosan to deionized water and stir at 500 r / min for 1.5 hours in a 65°C water bath until completely dissolved. Let stand at room temperature for 24 hours to remove bubbles and obtain hydroxypropyl chitosan solution. (4) Mix the hydroxypropyl cellulose solution and the hydroxypropyl chitosan solution, add the crosslinking agent, and stir at 600 r / min for 1.5 hours to form a mixed solution one; (5) Add dipropylene glycol, JFC-3 type surfactant, flame retardant and composite antifreeze to the mixed solution in sequence, continue stirring for 1.5 hours until uniform, let stand at room temperature for 18 hours to remove bubbles, and obtain mixed solution two; (6) Place the mixed solution 2 in a vacuum drying oven at 70°C to dry into a block solid, crush it and pass it through a 100-mesh sieve to obtain a powdered fire extinguishing gel.

[0045] Example 2 This embodiment provides a fire extinguishing gel and its preparation method. The fire extinguishing gel is composed of the following components by mass percentage: The composition includes 1.5% hydroxypropyl cellulose (HPC), 3% hydroxypropyl chitosan, 3% magnesium nitrate (crosslinking agent), 1.5% dipropylene glycol (DPG), 2% JFC-3 type surfactant, 5% diammonium hydrogen phosphate (DAP) (flame retardant), 3.5% composite antifreeze, and the balance being deionized water; the composite antifreeze is composed of propylene glycol and glycerin in a mass ratio of 1:1.

[0046] The preparation method of the fire extinguishing gel in this embodiment is the same as that in Example 1, and will not be repeated here.

[0047] Example 3 This embodiment provides a fire extinguishing gel and its preparation method. The fire extinguishing gel is composed of the following components by mass percentage: The composition includes 3% hydroxypropyl cellulose (HPC), 4.5% hydroxypropyl chitosan, 5% magnesium nitrate (crosslinking agent), 3% dipropylene glycol (DPG), 3% JFC-3 type surfactant, 6% diammonium hydrogen phosphate (DAP) (flame retardant), 5% composite antifreeze, and the balance being deionized water; the composite antifreeze is composed of propylene glycol and glycerin in a mass ratio of 2:1.

[0048] The preparation method of the fire extinguishing gel in this embodiment is the same as that in Example 1, and will not be repeated here.

[0049] Example 4 This embodiment provides a fire extinguishing gel and its preparation method. The fire extinguishing gel is composed of the following components by mass percentage: The composition includes 1% hydroxypropyl cellulose (HPC), 3% hydroxypropyl chitosan, 2% crosslinking agent magnesium nitrate, 3% dipropylene glycol (DPG), 2% JFC-3 type surfactant, 2% flame retardant diammonium hydrogen phosphate (DAP), 3% composite antifreeze, and the balance being deionized water; the composite antifreeze is composed of propylene glycol and glycerin in a mass ratio of 2:1.

[0050] The preparation method of the fire extinguishing gel in this embodiment is the same as that in Example 1, and will not be repeated here.

[0051] Comparative Example 1 This comparative example provides a fire extinguishing gel and its preparation method, wherein the fire extinguishing gel is composed of the following components by mass percentage: The composition includes 1% hydroxypropyl cellulose (HPC), 3% hydroxypropyl chitosan, 5% a mixture of magnesium chloride and magnesium nitrate as crosslinking agents, 3% dipropylene glycol (DPG), 1% JFC-type surfactant, 6% diammonium hydrogen phosphate (DAP) as flame retardant, and 5% composite antifreeze agent. The mass ratio of magnesium chloride to magnesium nitrate is 1:1, the mass ratio of propylene glycol to glycerol is 2:1, and the balance is deionized water.

[0052] The preparation method of the fire extinguishing gel in this comparative example is the same as that in Example 1, and will not be repeated here.

[0053] Comparative Example 2 This comparative example provides a fire extinguishing gel and its preparation method, wherein the fire extinguishing gel is composed of the following components by mass percentage: The composition includes 5% hydroxypropyl cellulose (HPC), 3% hydroxypropyl chitosan, 3.5% magnesium chloride (crosslinking agent), 2% dipropylene glycol (DPG), 2% JFC-3 type surfactant, 4% diammonium hydrogen phosphate (DAP) (flame retardant), 4% composite antifreeze, and the balance being deionized water; the composite antifreeze is composed of propylene glycol and glycerol in a mass ratio of 1.5:1.

[0054] The preparation method of the fire extinguishing gel in this comparative example is the same as that in Example 1, and will not be repeated here.

[0055] Comparative Example 3 This comparative example provides a fire extinguishing gel and its preparation method, wherein the fire extinguishing gel is composed of the following components by mass percentage: The composition includes 2% hydroxypropyl cellulose (HPC), 3% hydroxypropyl chitosan, 3.5% magnesium chloride (crosslinking agent), 2% dipropylene glycol (DPG), 2% JFC-6 type surfactant, 4% diammonium hydrogen phosphate (DAP) flame retardant, and 4% composite antifreeze agent, with the balance being deionized water. The composite antifreeze agent is composed of propylene glycol and glycerin in a mass ratio of 1.5:1. The preparation method of the fire extinguishing gel in this comparative example is the same as in Example 1, and will not be repeated here.

[0056] The application of the fire extinguishing gel of the present invention is described in detail through the following examples.

[0057] Application Example 1 This application example provides a fire extinguishing agent. The powdered fire extinguishing gel prepared in Example 1 is added to water and stirred evenly to obtain a fire extinguishing agent with a mass concentration of 3%.

[0058] Application Example 2 This application example provides a fire extinguishing agent. The powdered fire extinguishing gel prepared in Example 2 is added to water and stirred evenly to obtain a fire extinguishing agent with a mass concentration of 4%.

[0059] Application Comparative Example 1 This application provides a fire extinguishing agent by adding the powdered fire extinguishing gel prepared in Comparative Example 1 to water and stirring until homogeneous, resulting in a fire extinguishing agent with a mass concentration of 3%.

[0060] The performance of the fire extinguishing agents obtained from the application examples and the application comparison examples was tested.

[0061] Viscosity: According to GB / T 10247, Brookfield rotational viscometer RV rotor, 25±0.5℃, shear rate 100s. -1 ; Surface tension: 25±1℃, according to GB / T 22237-2008 Platinum Plate Method; pH: According to GB / T 9724 glass electrode method, 25℃; Electrical conductivity: According to ISO 7888, DJS-1 platinum black electrode, 25℃, electrode constant K = 1.0 cm⁻¹. -1 ; Temperature curve of cooling experiment: K-type thermocouple ( The sample is placed in the middle of the battery casing and on the tabs (≤1mm), with a sampling frequency of 1Hz. After the heating triggers the thermal runaway spray valve, the fire extinguishing agent is sprayed, and the temperature-time curve is continuously recorded for ≥30min.

[0062] Table 1

[0063] As can be seen from the data in Table 1, the viscosity and surface tension of the examples and application examples are both lower than those of the comparative example, which can effectively solve the problem of insufficient penetration and spreading ability in existing lithium-ion battery fire extinguishing applications. The pH levels are all neutral, which reduces the requirements for the storage environment and expands the application range. The electrical conductivity is also at a low level, avoiding reignition and a series of secondary hazards caused by short circuits during fire extinguishing.

[0064] Figure 1 and Figure 2 The fire-fighting experimental data from Application Example 1 and Application Comparative Example 1 for the dual-cell thermal runaway condition show that the extinguishing agent is released when the thermal runaway temperature of the adjacent cells reaches 600°C, and the release time is 180 seconds. Specifically, the largest surface of cell 1 is adjacent to the heating plate, and the largest surface of cell 2 is adjacent to cell 1. In Application Example 1, after releasing the extinguishing agent, a significant temperature drop occurs, and the second cell does not experience thermal runaway; the propagation of thermal runaway is effectively suppressed. In Application Comparative Example 1, after releasing the extinguishing agent, the temperature continues to rise, the second cell experiences thermal runaway, and the spread of heat is not effectively suppressed.

[0065] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A highly penetrating, rapidly spreading fire extinguishing gel, characterized in that, The raw materials include gelling agents, thickeners, surfactants, crosslinking agents, flame retardants, and antifreeze agents; The gelling agent is hydroxypropyl cellulose, the thickener is hydroxypropyl chitosan, and the surfactant is a JFC-type surfactant; the mass ratio of the JFC-type surfactant to the hydroxypropyl chitosan is 1:1 to 1.

5.

2. The fire extinguishing gel according to claim 1, characterized in that, The raw materials include the following components by weight: Hydroxypropyl cellulose 1 to 3 parts, hydroxypropyl chitosan 3 to 4.5 parts, JFC type surfactant 2 to 3 parts, crosslinking agent 2 to 5 parts, flame retardant 2 to 6 parts, antifreeze agent 3 to 5 parts.

3. The fire extinguishing gel according to claim 1 or 2, characterized in that, The JFC-type surfactant is the JFC-3 type surfactant.

4. The fire extinguishing gel according to claim 1 or 2, characterized in that, The crosslinking agent is selected from one or two of magnesium chloride and magnesium nitrate.

5. The fire extinguishing gel according to claim 3, characterized in that, The flame retardant is selected from diammonium hydrogen phosphate.

6. The fire extinguishing gel according to claim 4, characterized in that, The antifreeze is composed of propylene glycol and glycerin in a mass ratio of 1 to 2:

1.

7. The fire extinguishing gel according to any one of claims 1-6, characterized in that, The raw materials also include 1 to 3 parts of a moisturizing rheology modifier, preferably dipropylene glycol.

8. The fire extinguishing gel according to claim 7, characterized in that, The raw material consists of the following components by mass percentage: The composition includes 1.5%-2% hydroxypropyl cellulose, 3%-4.5% hydroxypropyl chitosan, 3.0%-3.5% magnesium chloride or magnesium nitrate, 1.5%-2% dipropylene glycol, 1.5%-3% JFC-type surfactant, 4%-5% diammonium hydrogen phosphate, 3.5%-4% composite antifreeze, with the balance being deionized water; the composite antifreeze is composed of propylene glycol and glycerin in a mass ratio of 1-1.5:

1.

9. A method for preparing a fire extinguishing gel as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Dissolve hydroxypropyl cellulose and hydroxypropyl chitosan in deionized water respectively, let stand to defoam, and obtain hydroxypropyl cellulose solution and hydroxypropyl chitosan solution; (2) The hydroxypropyl cellulose solution, hydroxypropyl chitosan solution and crosslinking agent are stirred and mixed to obtain a mixed solution; (3) The moisturizing rheology modifier, surfactant, flame retardant, and antifreeze are stirred and mixed with the mixed solution, allowed to stand to defoam, dried into block solid, and then crushed to obtain powdered fire extinguishing gel.

10. A hydrogel fire extinguishing agent, characterized in that, The fire extinguishing gel includes the fire extinguishing gel prepared by any one of claims 1 to 6 or any one of claims 7 to 9; preferably, the fire extinguishing gel is 2% to 5% of the mass of the hydrogel fire extinguishing agent.

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