Patent-based technological developments and surfactants application of lithium-ion batteries fire-extinguishing agent

While newer,more efficient Lithium-ion batteries(LIBs)and extinguishing agents have been developed to reduce the occurrence of thermal runaway accidents,there is still a scarcity of research focused on the application of surfactants in different LIBs extinguishing agents,particularly in terms of patented technologies.The aim of this review paper is to provide an overview of the technological progress of LIBs and LIBs extinguishing agents in terms of patents in Korea,Japan,Europe,the United States,China,etc.The initial part of this review paper is sort out LIBs technology development in different regions.In addition,to compare LIBs extinguishing agent progress and challenges of liquid,solid,combination of multiple,and microencapsulated.The subsequent section of this review focuses on an in-depth analysis dedicated to the efficiency and challenges faced by the surfactants corresponding design principles of LIBs extinguishing agents,such as nonionic and anionic surfactants.A total of 451,760 LIBs-related patent and 20 LIBs-fire-extinguishing agent-related patent were included in the analyses.The extinguishing effect,cooling performance,and anti-recombustion on different agents have been highlighted.After a comprehensive comparison of these agents,this review suggests that temperature-sensitive hydrogel extinguishing agent is ideal for the effective control of LIBs fire.The progress and challenges of surfactants have been extensively examined,focusing on key factors such as surface activity,thermal stability,foaming properties,environmental friendliness,and electrical conductivity.Moreover,it is crucial to emphasize that the selection of a suitable surfactant must align with the extinguishing strategy of the extinguishing agent for optimal firefighting effectiveness.

A review of fire-extinguishing agent on suppressing lithium-ion batteries fire

Safety issue of lithium-ion batteries(LIBs)such as fires and explosions is a significant challenge for their large scale applications.Considering the continuously increased battery energy density and wider large-scale battery pack applications,the possibility of LIBs fire significantly increases.Because of the fast burning and the easy re-ignition characteristics of LIBs,achieving an efficient and prompt LIBs fire suppression is critical for minimizing the fire hazards.Different from conventional fire hazards,the LIBs fire shows complicated and comprehensive characteristics,and an effective and suitable fire-extinguishing agent particularly designed for LIBs is highly desirable.Considerable efforts have been devoted to this topic,to the best of our knowledge,a comprehensive review on this regard is still rare.Moreover,in practice,a guidance for the design and selections of a proper fire-extinguishing agent for LIBs is urgently needed.Herein,the special mechanisms and characteristics for LIBs fire and the corresponding design principles for LIBs fire-extinguishing agent were introduced.It is revealed that a fire-extinguishing agent developed for LIBs fire will most likely need a high heat capacity,high wetting,low viscosity and low electrical conductivity.After a comprehensive comparison of these agents in terms of these performances,water-based fire-extinguishing agents show best.Several typical fire-extinguishing agents such as gaseous agents,dry powders,water-based and aerosol fire-extinguishing agents were then introduced,and their fire extinguishment mechanisms were presented.Finally,their effectiveness in suppressing the fire were summarized.Water-based fire-extinguishing agents possess high cooling capacity and excellent anti-reflash performance for the fire.We believe this review could shed light on developing an efficient fire-extinguishing agent particularly designed for LIBs.

FIRE-EXTINGUISHING MECHANISM AND ENERGY PROCEDURE BY HIGH VELOCITY AIRFLOW

Based on the testing restult of character of forest fire, with the aid mold of flameextinguishing and mathematical method, the combustion of the forest fuels and the energy transtfer under the convention condition were studied and the mechanism and interrelated elements of flameextinguishing with high velocity airflow were given. The energy formulae is given:Nz =Ka0 L0 (15)GH/102η through combustion calculation and test revision This formula was checked through simulated testing for extinguishing low, medial and high intensity fires with high velocity airflow.

超细干粉灭火剂

首先简介了干粉灭火剂的种类、特点、性能,讨论了燃烧机理、传统干粉灭火剂及其灭火原理,重点探讨了灭火剂粒径与灭火效能之间的关系,发现灭火效能随粒径减少而急剧增加。最后,探讨了超细粒径干粉灭火剂的性能、研制和生产情况、优势及前景,并分析了纳米干粉灭火剂的性能和应用前景。

氢氧化镁对磷酸二氢铵灭火剂性能的影响

在市售以磷酸二氢铵为灭火基料的ABC干粉灭火剂中加入氢氧化镁,利用自制实验装置对干粉灭火剂进行灭火性能、灭火温降实验测试。实验结果表明:氢氧化镁含量低于10%时,灭火剂灭火性能没有改善;氢氧化镁含量为20%时,干粉灭火效率、灭火后温降速率明显提高。

Modification of ADP extinguishing powder by siliconization in spray drying

Superfine spherical fire-extinguishing powder, ammonium dihydrogen phosphate （ADP, NH4 H2 PO4）, was prepared by spray drying and modified in situ with methyl hydrogen silicone oil （MHSO） emulsion and the fluorinated surfactant FK-510. The influences of the MHSO mass ratio on the hydrophobicity, sur- face composition, surface morphology, dispersion and particle-size distribution of the NH4H2PO4 were studied, and the influence of the drying air temperature on the decomposition of the NH4H2PO4 was also researched. The results indicate that the MHSO and FK-510 congregate on the particle surfaces and then form a hydrophobic shell. This shell improves the particle hydrophobicity and leads to a fine dispersion of the particles. During the process of preparing the precursor solution, 3 wt% （based on the weight of NH4H2 PO4 ） was chosen as the optimum value of the MHSO mass ratio. During the spray drying, a low abso- lute humidity of the air should be maintained, and it is very important to keep the exit-air temperature below 100℃ to avoid decomposition.