AA Carbon battery.The source of spontaneous combustion in new energy vehicles is mostly lithium batteries, and there is still room for upgrading technical standards.

　　As one of the most influential new energy vehicle brands in the world, Tesla has been regarded as a target for learning and catching up by many car brands. Nowadays, with the frequent occurrence of spontaneous combustion incidents, whether Tesla cars and even electric cars are safe has become a topic of concern to many people. Although no one doubts that "electrification" has become an irresistible trend in the development of the global automobile industry. However, the recent frequent spontaneous combustion accidents have once again pushed new energy vehicles to the forefront of public opinion. On April 21, a Tesla Model S spontaneously ignited in Shanghai. According to on-site surveillance video, the Tesla Model S parked in the underground garage suddenly caught fire and ignited several vehicles nearby. Users of the building were also arranged to evacuate, causing heavy losses. On May 12, a Tesla Model S spontaneously ignited half an hour after it was parked in San Po Kong Plaza, Hong Kong. There were three explosions during the combustion process. It took firefighters 45 minutes to extinguish the fire. According to reporters, in just two months, four spontaneous combustion incidents have occurred in Tesla’s electric vehicles around the world. As one of the most influential new energy vehicle brands in the world, Tesla has been regarded as a target for learning and catching up by many car brands. Nowadays, with the frequent occurrence of spontaneous combustion incidents, whether Tesla cars and even electric cars are safe has become a topic of concern to many people. Recently, reporters interviewed a number of industry experts and scholars on whether new energy vehicles are safe, how to deal with spontaneous combustion accidents, and what improvements and upgrades are needed in the development of new energy vehicles to find the problems and solutions behind the spontaneous combustion of electric vehicles. . The source of spontaneous combustion is mostly lithium battery. The technical standards of new energy vehicles still have room for upgrading. "After dismantling, I saw that of the entire Tesla battery module (a total of 16 groups), only four modules near the front of the car had been burned. The remaining 12 None of the modules have been affected. If the fire is extinguished later, more lithium battery modules (the source of powerful deflagration) may be affected and deflagrate..." After the spontaneous combustion of Tesla Model S, the owner of the car, Mr. Dong, has I haven't slept for more than 30 hours. In addition to fear and anger, the biggest question in his mind is: "Why did a vehicle bought at a high price spontaneously ignite under static conditions?" "The incident is currently under investigation, and no preliminary judgment or conclusion has been formed. We will actively cooperate with the investigation. , announce the investigation results in a timely manner, and please do not spread or believe rumors." Three days after the spontaneous combustion of Tesla Model S, Tesla announced on its official Weibo. Although Tesla has not yet given an official investigation conclusion, after the Tesla Model S spontaneously ignited, Shanghai fire scene experts, judicial experts, and automobile experts rushed to the scene for investigation as soon as possible. Tao Wei, an expert on vehicle defect investigation and identification and recall from the General Administration of Quality Supervision, Inspection and Quarantine, said that at present, the cause of the Tesla Model S fire is a battery short circuit, and identification will continue in the future. In fact, this is not the first time that new energy vehicles, especially pure electric vehicles, have spontaneously ignited. According to incomplete statistics, there were more than 40 electric vehicle fire incidents across the country in 2018, and the vehicles covered different models such as passenger cars, buses, and logistics vehicles. In Shenzhen alone, eight spontaneous combustion accidents of new energy logistics vehicles occurred. According to Liu Zhichao, an analyst in the automotive industry, there are many and complex reasons for spontaneous combustion of electric vehicles, but the main problem is the battery. For example, an internal short circuit in the battery is one of the common causes. "For example, when the car is vibrating, the material coating the positive and negative electrodes of the battery plate falls off, and a short circuit occurs in the battery. This kind of internal short circuit in the battery is difficult to control and may induce spontaneous combustion." In addition, Liu Zhichao pointed out that the battery's internal short circuit is difficult to control. Loose connections resulting in poor external contact, or overcharging or over-discharging the battery may cause the internal temperature of the battery to rise and cause spontaneous combustion. "Because there is a process for the temperature to rise to spontaneous combustion, it will catch on fire when it is parked in the basement, just like Tesla's car this time. It is neither charging nor driving." Big data confirms The view that "most sources of spontaneous combustion of new energy vehicles are batteries". The Qianzhan Industry Research Institute analyzed and counted the fire accidents of new energy vehicles since 2017 and found that among the causes of fire accidents, spontaneous combustion of power batteries accounted for 31%, mainly due to the short-term internal or external short circuit of the lithium battery. The internal battery releases a large amount of heat and the temperature rises sharply, causing thermal runaway. "Unscientific cost requirements have increased safety risks. In recent years, popular practices in the battery industry such as simplified system design and increased capacity of single cells have increased battery safety risks." Liu Zhichao said bluntly, "Take Tesla as an example. In order to reduce weight and cost, Tesla eliminated the outermost insulation layer of the battery, further intensifying the risk." It is not just car companies that need help from many parties to ensure the safe development of electric vehicles. "The batteries of new energy vehicles have very high technical requirements. High." Ouyang Minggao, academician of the Chinese Academy of Sciences and director of the State Key Laboratory of Automotive Safety and Energy Conservation, said that the power battery will generate heat during operation, which is controllable under normal circumstances, but when the battery temperature is too high or the charging voltage is too high, the battery will Internal chemical reactions will occur one after another, resulting in a chain reaction, causing the internal pressure and temperature of the battery to rise sharply, causing thermal runaway of the battery, causing combustion or explosion. Regardless of changes in external use and environmental issues, the cause of heating is also closely related to its own manufacturing materials and processes. Problems such as excessive battery use, uneven battery pack temperature, short circuit, etc. may lead to thermal runaway. "If you want to reduce or even avoid the occurrence of spontaneous combustion incidents in new energy vehicles, you must first carry out strict controls at the technical level." Sun Fengchun, an academician of the Chinese Academy of Engineering and an expert on new energy vehicles, said that from a technical perspective, there are two ways to solve the problem of electric vehicle fires. The first route is to use pure solid electrolytes, but it is difficult to achieve in the short term; the second is to "develop an absolutely safe control system." "my country's new energy vehicle policy orientation has always encouraged high energy density in the past. In order to meet the requirements, car companies received more subsidies and rapidly improved this indicator. But now many car companies will also pay attention to safety factors, such as re-selecting lithium iron phosphate batteries. "He introduced. In addition to strictly controlling the production process and making technological breakthroughs, mastering certain escape methods is also an important means to protect safety in the event of vehicle spontaneous combustion. "If you are around the vehicle when it spontaneously ignites, you must stay away from the spontaneously igniting vehicle as soon as possible. Pure electric vehicles spontaneously ignite very quickly, especially when the battery pack is short-circuited, and a deflagration may occur within tens of seconds. and other phenomena." Tao Wei reminded, "On the premise of ensuring that you are in a safe environment, call the police as soon as possible, and then contact the insurance company and relevant brand 4S stores to assist on-site. In general, safety is the first priority One person." The frequent spontaneous combustion accidents of electric vehicles have not only attracted public attention to the safety issues of new energy vehicles, but the distribution of accident liability and compensation have also become hot topics in the industry. "Take the Shanghai Tesla Model S spontaneous combustion accident as an example. The cause of the Tesla Model S spontaneous combustion accident has been initially determined to be caused by a battery short circuit problem, which can basically be characterized as spontaneous combustion. If Tesla owners do not purchase spontaneous combustion insurance, the insurance company will Will refuse compensation." Yang Liang, a lawyer at Dacheng Law Firm, told reporters, "Car owners can only insure vehicle spontaneous combustion insurance on the basis of motor vehicle loss insurance." Therefore, Yang Liang suggested that owners of Tesla Model S spontaneous combustion accidents If you do not purchase spontaneous combustion insurance, you can defend your rights against the seller on the grounds that the new energy vehicle has quality defects. "The seller should be responsible for repairing, replacing or returning goods and compensating for losses. If it is the manufacturer's responsibility, the seller will recover from the manufacturer and supplier." In fact, compared with the fuel vehicles that have been developed for more than 100 years, new energy vehicles The short development time and rapid development speed have also caused the problem that relevant laws and regulations are not yet complete to a certain extent. Feng Jun, secretary-general of the Accident Vehicle Repair Committee of the China Automobile Maintenance Industry Association, said in an interview that my country's new energy vehicle insurance clauses have not yet been introduced, and most companies use traditional fuel vehicle insurance clauses to insure electric vehicles. He appealed: "Nowadays, the production, sales and ownership of electric vehicles are growing rapidly. We must accelerate the promotion of exclusive insurance for electric vehicles and introduce it as soon as possible."

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