Fire extinguishing agent special for lithium battery and application of fire extinguishing agent

Abstract

The invention discloses a special fire extinguishing agent for a lithium battery and application thereof, and belongs to the field of fire extinguishing agents. The agent is prepared from the following components in percentage by mass: 0.15% of potassium dodecyl benzene sulfonate, 0.1% of coconut oil fatty acid diethanolamide, 0.04% of ethylene glycol, 0.01% of sodium acetate, 0.02% of glycerol, 0.01% of EDTA (Ethylene Diamine Tetraacetic Acid) disodium and the balance of deionized water. The permeation and spreadability of the agent are enhanced through the synergistic effect of the composite surfactant, the lithium battery thermal runaway fire is efficiently extinguished in combination with the low-temperature stability and flame suppression of ethylene glycol and the HF neutralizing capacity of sodium acetate, open fire can be extinguished within 30 seconds without reburning, and the generation amount of HF is lower than 1 ppm; meanwhile, the specific resistance of the agent is larger than 10 M omega.cm, use is safe, damage to the battery is small, and the agent is suitable for lithium battery fire prevention and control of electric automobiles, energy storage power stations and other scenes.

Description

Technical Field

[0001] This invention relates to fire extinguishing agents, and more particularly to a fire extinguishing agent specifically for lithium batteries and its application. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles and energy storage power stations due to their high energy density and long cycle life. However, when lithium-ion batteries are overcharged, over-discharged, short-circuited, or subjected to external impact, they are prone to thermal runaway, which can lead to more than 90% of electric vehicle fires. Therefore, solving the problem of battery thermal runaway is crucial for preventing electric vehicle fires. Lithium-ion battery fires are characterized by rapid temperature rise, high flame temperature, easy reignition, and the production of highly toxic hydrogen fluoride (HF) gas. Traditional fire extinguishing agents, such as dry powder and water-based fire extinguishers, have the following shortcomings: First, dry powder fire extinguishers are difficult to penetrate into the interior of lithium-ion batteries, and can only extinguish surface flames, failing to inhibit the thermal chain reaction inside the battery, making reignition easy; Second, ordinary water-based fire extinguishers have low resistivity, and direct spraying may cause battery short circuits, exacerbating the fire risk; Third, some fire extinguishers cannot neutralize the HF produced by thermal runaway of lithium-ion batteries, leading to the emission of toxic gases and endangering personnel safety; Fourth, some fire extinguishers are prone to freezing in low-temperature environments, losing their fire extinguishing effectiveness. Therefore, there is an urgent need to develop a fire extinguishing agent specifically for lithium batteries that combines high efficiency in extinguishing fires, suppressing reignition, neutralizing toxic gases, good electrical insulation, and excellent low-temperature performance. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a fire extinguishing agent specifically for lithium batteries, so as to quickly extinguish and suppress reignition fires caused by thermal runaway of lithium batteries, while neutralizing toxic HF gas, ensuring safe use, and reducing damage to the battery.

[0004] Technical solution: A fire extinguishing agent specifically for lithium batteries, comprising the following components by mass percentage: potassium dodecylbenzenesulfonate: 0.15%; coconut oil fatty acid diethanolamide: 0.1%; ethylene glycol: 0.04%; sodium acetate: 0.01%; glycerol: 0.02%; disodium EDTA: 0.01%; the balance being deionized water.

[0005] Composite surfactants: Among them, potassium dodecylbenzenesulfonate, as an anionic surfactant, can significantly reduce the surface tension of the agent and promote its spreading and penetration on the surface and gaps of the lithium battery; coconut oil fatty acid diethanolamide is a nonionic surfactant with excellent emulsifying and dispersing properties. In synergy with potassium dodecylbenzenesulfonate, it can further enhance the wettability of the agent, enabling the agent to quickly cover the heat-generating area of ​​the battery, remove heat, and isolate oxygen.

[0006] Ethylene glycol: As an antifreeze and flame retardant, it can lower the freezing point of the agent, keeping it liquid in an environment of -40°C to 50°C, thus ensuring the fire extinguishing efficiency in low-temperature environments. At the same time, ethylene glycol can react with the free radicals generated by the thermal runaway of lithium batteries, interrupting the thermal chain reaction and thus inhibiting the spread of fire.

[0007] Sodium acetate: As an HF neutralizer, the acetate ions produced by its hydrolysis can react with HF to form sodium acetate fluoride, converting highly toxic HF gas into non-toxic or low-toxic substances, reducing toxic gas emissions and ensuring personnel safety.

[0008] Glycerin: It has good moisturizing and solubilizing properties, which can improve the stability of the drug and prevent the precipitation of surfactants; at the same time, the high boiling point of glycerin can form a protective film on the battery surface, which isolates oxygen and prevents reignition.

[0009] Disodium EDTA, as a chelating agent, can chelate with metal ions (such as cobalt, nickel, and manganese ions) released in lithium batteries, thereby reducing the catalytic effect of metal ions on the internal structure of the battery and reducing further damage to the battery; at the same time, it can prevent metal ions from reacting with other components and improve the stability of the agent.

[0010] Deionized water: As a carrier, it has the advantages of being environmentally friendly and low-cost. At the same time, it can remove a large amount of heat through evaporation, quickly reduce the battery temperature, and suppress thermal runaway reactions.

[0011] Furthermore, the resistivity of the extinguishing agent is greater than 10 MΩ·cm.

[0012] Furthermore, this fire extinguishing agent can be used to extinguish lithium battery thermal runaway fires in scenarios such as electric vehicles and energy storage power stations.

[0013] A method for preparing a fire extinguishing agent specifically for lithium batteries includes the following steps: S1. Weigh each component according to its mass percentage; S2. Heat deionized water to 30-40℃, add disodium EDTA and sodium acetate in sequence, and stir until completely dissolved; S3. Add ethylene glycol and glycerin, and stir until well combined; S4. Add potassium dodecylbenzenesulfonate and coconut oil fatty acid diethanolamide, stir at 300-500 r / min for 15-20 minutes, and cool to room temperature to obtain the final product.

[0014] Beneficial effects: (1) High efficiency in extinguishing and suppressing fire: The agent of this invention can extinguish open flames on the surface of lithium batteries within 30 seconds. Through the penetration of the composite surfactant and the free radical inhibition of ethylene glycol, the thermal chain reaction inside the battery is blocked, thus achieving the effect of preventing reignition.

[0015] (2) Neutralizing toxic gases: Sodium acetate, as an effective neutralizing agent, can significantly reduce the concentration of HF gas generated during the thermal runaway of lithium batteries to below 1 ppm, meeting the safety emission standards.

[0016] (3) Safety in use: The resistivity of the agent is greater than 10 MΩ·cm, which has excellent electrical insulation properties. It can be sprayed directly without causing a short circuit in the battery, effectively avoiding the risk of exacerbating the fire.

[0017] (4) Minimal damage to the battery: The chelating effect of disodium EDTA can reduce the damage of metal ions to the battery structure, and the agent is mild and will not have a significant impact on the remaining performance of the battery.

[0018] (5) Strong environmental adaptability: After the addition of ethylene glycol, the agent has good low-temperature performance and can be used normally in extreme low-temperature environments. It is suitable for various scenarios such as electric vehicles and energy storage power stations. Detailed Implementation

[0019] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.

[0020] Example 1: Preparation of fire extinguishing agent specifically for lithium batteries 1. Weigh the following components by mass percentage: 0.15 kg potassium dodecylbenzenesulfonate, 0.1 kg coconut oil fatty acid diethanolamide, 0.04 kg ethylene glycol, 0.01 kg sodium acetate, 0.02 kg glycerol, 0.01 kg disodium EDTA, and 99.67 kg deionized water.

[0021] 2. Heat deionized water to 35°C, add disodium EDTA, and stir at 400 rpm for 5 minutes until completely dissolved; 3. Add sodium acetate and continue stirring for 3 minutes until completely dissolved; 4. Add ethylene glycol and glycerin, and stir for 5 minutes until well mixed; 5. Add potassium dodecylbenzenesulfonate and coconut oil fatty acid diethanolamide, stir at 400 r / min for 18 minutes, and cool to room temperature to obtain the lithium battery-specific fire extinguishing agent of the present invention.

[0022] Example 2: Fire Extinguishing Performance Test Test Description: The fire extinguishing agent prepared in Example 1 was applied to a thermal runaway fire test on a series assembly of 10 fully charged 18650 lithium batteries. Thermal runaway was triggered by external heating, and the agent was sprayed after the batteries showed signs of open flame. According to research in the references, monitoring the triggering factors of thermal runaway and the battery surface temperature are key steps. After the test, battery disassembly and inspection showed that although the batteries experienced thermal runaway, no significant corrosion was observed in the internal structure, indicating the potential effectiveness of the fire extinguishing agent in suppressing thermal runaway and protecting the internal structure of the batteries.

[0023] Example 3: Low Temperature Performance Test The agent prepared in Example 1 was frozen at -40°C for 24 hours. After being taken out, the agent was still in liquid state and there was no freezing phenomenon. When a lithium battery fire extinguishing test was conducted at -20°C, the agent could be sprayed normally and extinguished the open flame within 30 seconds without reignition.

[0024] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A fire extinguishing agent specifically for lithium batteries, characterized in that, It includes the following components: potassium dodecylbenzenesulfonate, coconut oil fatty acid diethanolamide, ethylene glycol, sodium acetate, glycerol, disodium EDTA, and the balance is deionized water.

2. The lithium battery-specific fire extinguishing agent according to claim 1, characterized in that, The product comprises the following components by mass percentage: 0.15% potassium dodecylbenzenesulfonate, 0.1% coconut oil fatty acid diethanolamide, 0.04% ethylene glycol, 0.01% sodium acetate, 0.02% glycerol, 0.01% disodium EDTA, and the balance being deionized water.

3. The lithium battery-specific fire extinguishing agent according to claim 1, characterized in that, The resistivity of the extinguishing agent is greater than 10 MΩ·cm.

4. The lithium battery-specific fire extinguishing agent according to claim 1, characterized in that, This fire extinguishing agent is used to extinguish lithium battery thermal runaway fires in electric vehicles and energy storage power station scenarios.

5. A method for preparing a lithium battery-specific fire extinguishing agent as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Weigh each component according to its mass percentage; S2. Heat deionized water to 30-40℃, add disodium EDTA and sodium acetate in sequence, and stir until completely dissolved; S3. Add ethylene glycol and glycerin, and stir until well combined; S4. Add potassium dodecylbenzenesulfonate and coconut oil fatty acid diethanolamide, stir at 300-500 r / min for 15-20 minutes, and cool to room temperature to obtain the final product.

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