From this 2018
paper:
... F-500 micro capsule’s material technology, which is a new high efficiency fire extinguishing, explosion prevention and environmental technology developed by the American dangerous goods Control Arts Inc (HCT). In 2009, Bosch tested the extinguishing effect of water, foam, powder and F-500 on lithium battery fires. The tests found that F-500 is the first choice of lithium battery fire extinguishing agent.
In April 2013, German motor vehicle inspection association (DEKRA) selected three kinds of fire extinguishing agent, and studied the extinguishing effect on power lithium battery fire of electric vehicle [9]. According to the structure of electric vehicle’s lithium battery, DEKRA used n-heptane to ignite lithium battery and set up fire model. They compared F-500 fire extinguishing agent’s effect with water and powder fire extinguishing agent’s effect on extinguishing lithium battery fire. Firefighters began to fight fire after n-heptane combustion’s time at about 20min. Through simulation experiments, DEKRA found that water can successfully extinguish the lithium battery fire of electric vehicles.
But there are many other problems, such as large water consumption and long extinguishing time. F-500 fire extinguishing agent can improve the efficiency of extinguishing lithium battery fires. The extinguishing time of extinguishing agent containing 1% F-500 is only fourteen seconds. The water consumption is greatly reduced. As a kind of micro cellular agent, F-500 can effectively inhibit class D (metal) fire in which no explosion exists. When the water is applied to class D (metal) fire, high temperature can make water into hydrogen and oxygen. The after-combustion and explosion will occur easily. Powder extinguishing agent can not cool the fire, and the fire will happen again. F-500 can reduce the surface tension of water. The formation of smaller droplets can make them penetrate into the internal of lithium battery. They quickly extinguished the fire and the fire will not happen again. F-500 forms a layer of protective film on the surface of the water forming a spherical micro capsule "chemical cocoon". The fuel Wei-tao LUO et al. / Procedia Engineering 211 (2018) 531–537 535 Wei-tao LUO et al./ Procedia Engineering 00 (2017) 000–000 and Purple-K, were sprayed by a hand-held bottle. After the fire was over, the heater was closed and data was recorded for about 20 minutes.The results showed that all thermal runaway of lithium battery occurred and spread in the absence of fire extinguishing agents, and only 500ml liquid fire extinguishing agents can effectively inhibit the spread of lithium-ion battery fire. Non-liquid fire extinguishing agents had no effect on lithium-ion battery. Through the research of this project, FAA found that the experimental results of fire extinguishing agents’ cooling effect are similar to the experimental results of lithium battery fire extinguishing. It further testified that the cooling ability of fire extinguishing agents is the key factor to prevent the spread of lithium battery fire. Water based fire extinguishing agents had the best effect on the suppression of lithium battery fires, while gas extinguishing agents and dry powder extinguishing agents are ineffective in suppressing lithium battery fires. 3.2. The study on fire extinguishing of lithium battery in China In order to reduce the risk of lithium battery fires, Wuhan Institute of China Classification Society [7] carried out the research on the effectiveness of extinguishing agent of fighting power lithium battery fire. They analyzed the effectiveness of carbon dioxide, dry powder and heptafluoropropane which inhibit lithium battery fire. They evaluated its effectiveness from three aspects such as the fire extinguishing time, the recrudescence rate and smoke effect synthetically.The experiment found that the carbon dioxide’s extinguishing effect is poor and the resurgence of fire occurred. Dry powder extinguishing agent has little effect on the lithium battery, and explosion occurred even during the experiment. The best effect on extinguishing lithium battery fires is heptafluoropropane. University of Science and Technology of China [8] carried out the research on the effectiveness of dry powder, carbon dioxide and heptafluoropropane of extinguishing lithium battery fires. It was found that heptafluoropropane has good effect, but also the resurgence of fire occurred. Tianjin fire station of Ministry of public security [3] conducted the experiment of extinguishing lithium battery fires with the powder, carbon dioxide and AFFF fire extinguishing agent and water mist technology. The results showed that the carbon dioxide, dry powder, 3% AFFF can extinguish the open fire of 18650# lithium-ion batteries. Due to the thermal runaway of lithium-ion batteries, it continued to release heat, combustible gas and oxygen. It can not extinguish the fire completely. All of them appeared resurgence phenomenon. With the fire extinguishing agent’s cooling ability increasing, the time of appearing resurgence prolonged. For completely extinguishing 18650# lithium-ion battery fires, it needs to improve the fire extinguishing agent’s ability of cooling and absorbing heat. Water mist fire extinguishing technology can not inhibit the 18650# lithium-ion battery fires effectively. Some studies showed that [4,5] water mist containing surface active agent is an efficient and environmental fire extinguishing technology. The utility of lithium battery fire needs further study. 3.3. Application of F-500 micro capsule technology and water mist containing additives system in the lithium battery fire extinguishing There are few studies on the micro capsule technology of explosive hydrocarbons in the literature, and the results of existing research are concentrated mainly in developed countries. The existing advanced technology is F-500 micro capsule’s material technology, which is a new high efficiency fire extinguishing, explosion prevention and environmental technology developed by the American dangerous goods Control Arts Inc (HCT).