Electric vehicles catch fire instantly after hitting the toll booth, why are new energy vehicles prone to fire after collision?
At about 5:43 this morning, an electric vehicle with Zhejiang A license plates drove out of the Hangzhou toll station along the S2 Shanghai-Hangzhou Expressway when it collided with the toll station facilities and caught fire, killing four people on board.
It can be seen from the video that the electric car did not seem to slow down when entering the toll booth, directly smashed the water horse on the safety island next to the toll channel, and then collided violently with the cement pier of the safety island, and the vehicle instantly caught fire, and the thick smoke accompanied by the flames engulfed the entire car.
After many inquiries, Orange Persimmon Interactive learned that the vehicle involved in the incident had not been driving on the highway for a long time before the incident, and the vehicle was suspected to have no signs of slowing down at the time of the incident. Whether it is the driver's physical cause, or the accelerator as a brake or the performance of the vehicle that caused the accident, still needs to be further investigated by the police.
The electric car that caused the accident was a SAIC Volkswagen new energy vehicle ID.4X. The car is the first pure electric SUV launched by Volkswagen, which will be launched in 2021, when the guidance price range after subsidies was 199,888-272,888 yuan.
The ID.4X is derived from the Volkswagen ID.4, which won the 2021 World Car of the Year Award, and forms a two-car strategy with the FAW-Volkswagen I.D 4 CROZZ.
Orange Persimmon Interactive noticed that in the crash test of the China Insurance Research Institute in October 2021, the car achieved excellent results in all four categories, including a 25% offset collision.
In this traffic accident, why did the ID.4X catch fire immediately after the collision?
It is reported that this car is equipped with NCM811 system ternary lithium battery, the internal battery cells are provided by CATL and assembled by SAIC Volkswagen itself. According to the publicity of the publicity, the battery has passed 338 brand standard battery safety certifications, covering K13 temperature shock, chemical corrosion, extreme collision, etc., more than more than 200 national safety standards.
Ternary lithium battery refers to a lithium battery that uses nickel-cobalt manganate ternary cathode material for cathode materials. Compared with lithium iron phosphate batteries, ternary lithium batteries have a higher energy density, and the same weight of battery pack has a larger battery capacity, and the car runs farther. However, compared with other types of batteries, its stability performance is slightly worse, and it is more likely to fire and explode due to thermal runaway.
Song Jian, a professor at the School of Vehicles and Vehicles at Tsinghua University, once said: "Easy fire after collision is a characteristic of new energy electric vehicles, the battery does not need to be broken, only need to have a large enough impact to catch fire." ”
Of course, the specific cause of this accident has yet to be investigated by the relevant departments.
In fact, not only ternary lithium batteries, but also other types of batteries can cause vehicle fires in the event of similar traffic accidents:
On April 5, 2023, Qingming Day, a BYD Han collided and caught fire at the Cen Xi East exit of Baomao Expressway, and the people in the car failed to escape in time.
On September 5, 2022, a Porsche Taycan crashed into a guardrail and caused a fire, and passers-by wanted to rescue but could not open the door from the outside, causing the people in the car to be unable to escape and escape.
On July 22, 2022, Lin Zhiying drove a Tesla to hit a bridge pier on Zhongzhengbei Road in Taoyuan, and Tesla instantly ignited a violent fire, and Lin Zhiying's father and son were rescued by the public and sent to the hospital.
On November 11, 2021, an ideal ONE caught fire after rear-end a NIO EC6 on the highway, but fortunately both drivers and occupants were fine.
The power battery of new energy vehicles is generally installed on the chassis, which is not easy to be detected after the collision, and the fire is fast, which is more difficult to extinguish, so the danger is higher. In May 2020, the Ministry of Industry and Information Technology issued three mandatory national standards, including "Electric Vehicle Safety Requirements", "Electric Bus Safety Requirements" and "Electric Vehicle Power Battery Safety Requirements", which were officially approved, and began to be implemented on January 1, 2021.
These three strong standards not only propose to improve the safety standard requirements of electric vehicles, strengthen the accuracy of test and detection, but also stipulate that electric vehicles need to add battery system thermal event alarm signals and other technical details. It is also required that after the thermal runaway of the battery cell, the battery system will not catch fire and not explode within 5 minutes.
In March last year, the Ministry of Industry and Information Technology issued the "2022 Automotive Standardization Points" clearly stated that the revision of electric vehicle power battery safety related standards should be initiated to further improve the thermal runaway alarm and safety protection level of power batteries.
In order to avoid spontaneous combustion of batteries and fires after collisions, new energy vehicle companies are also strengthening corresponding safety design and research. Some automotive industry experts said, "The current product should be able to ensure normal use, some minor failures, collisions and scratches will not have any problems." ”
With the rapid popularization of new energy vehicles, from power battery materials to power battery processes to power battery management systems (BMS), whether it is OEMs or power battery manufacturers, the importance of new energy vehicle safety is increasing.
People in the power battery industry said, "The reasons for the safety of new energy vehicles are complex, there are internal factors and external factors. From the perspective of the battery itself, from the thermal stability of the material, the high voltage resistance of the single battery, the overcharge resistance technology to make a breakthrough, and at the same time from the aspect of system integration to focus on the prevention of thermal diffusion of the system, the internal short circuit caused by the manufacture of the single battery is difficult to completely avoid at present. We can reduce the probability of accidents through the improvement of technology. "In this regard, everyone does not have to worry too much, and even dare not use new energy vehicles." As long as the owner understands the battery characteristics of the new energy vehicle while using it, and pays attention to the safety of the use process, such as not overcharging, not using fast charging for a long time, etc., it will not have greater risks than fuel vehicles.