Produced by Sanyan Finance
Author｜Dapeng
Recently, artist Lin Zhiying suffered a car accident, which attracted widespread attention.
According to media reports, the car accident occurred around 10:50 a.m. At that time, Lin Zhiying took his son out together and drove a white Tesla. However, the vehicle suddenly hit a separation island while driving, causing serious damage to the vehicle and starting to burn.
It is worth mentioning that the car in this accident was an electric car and it caught fire again.
Before this, electric vehicle fire accidents occurred frequently. This begs the question, why do electric cars always catch fire?
Electric vehicle fire accidents occur frequently
Some car companies are recalling vehicles due to fire risks
Here, Sanyan Finance will first take stock of the electric vehicle fire accidents since last year.
On April 14, 2021, a Xpeng G3 car caught fire outside the parking lot of the Mayor's Building in Guangzhou.
According to live video, the vehicle fire was relatively large, and a large number of property management, security and other personnel were on site trying to put out the fire. Later, firefighters arrived and put out the fire.
On the evening of April 17, 2021, local time, a traffic accident occurred in Texas, USA. A Tesla Model S hit a tree while driving and caught fire. The accident resulted in the death of two men in the car.
At about 9 pm on April 17, 2021, a Tesla car was seriously burned after a collision on Dongjiang Avenue North in Zengcheng, Guangzhou.
On the morning of May 19, 2021, a Tesla Model 3 spontaneously ignited after hitting a tree on Xinghai Avenue, Lanhe Town, Nansha District, Guangzhou City. After the incident, the suspected car owner stated in his fan group that the vehicle was traveling too fast and lost control before hitting a tree. The vehicle started to catch fire about 15 minutes later.
In July 2021, the automotive media conducted a collision experiment between BYD Han EV and Jihu Alpha S. The two vehicles collided at a speed of 64 kilometers per hour with a 50% bias. After the two vehicles collided at high speed, the battery was completely powered off and no smoke appeared. However, 48 hours after the collision test, the BYD Han EV caught fire when the entire vehicle was powered off and all weak batteries were powered off.
On July 30, 2021, some media released a video of a NIO EC6 colliding and catching fire. In the video, a NIO EC6 electric vehicle collided and caught fire in Pudong, Shanghai, killing the driver.
In November 2021, a Weibo big V forwarded the news to a netizen who said that on November 11, an Ideal ONE caught fire after rear-ending a Weilai EC6 on the highway.
Judging from the exposed pictures, both cars suffered varying degrees of damage after the collision. Among them, the rear of the Weilai EC6 was seriously damaged and deformed. The rear trunk glass was broken, one side of the bumper was dented, and the taillights were cracked.
There was a fire in the front engine room of Ideal ONE.
On the evening of November 22, 2021, a BYD Qin Pro EV caught fire and exploded in the underground garage of Zhongguancun No. 1 Park in Beijing.
According to screenshots posted on WeChat Moments by the owner of the vehicle involved, the owner picked up his child and got out of the car when he heard something was wrong in the car. Then the vehicle exploded, causing no casualties.
On January 12 this year, a Tesla Model Y caught fire in a surface parking lot. Tesla responded that the accident was caused by a new energy online ride-hailing car that caught fire during charging and ignited the Tesla Model Y next to it. The accident had nothing to do with Tesla.
It is worth noting that although Tesla claimed that it had nothing to do with it, the fire was also caused by a new energy vehicle.
In February this year, some netizens broke the news that an Ideal ONE car caught fire in the parking lot.
According to the photos, the fire was suspected to have started in the front cabin of the vehicle, and the fire was so fierce that the entire vehicle had been burned into an empty shell.
In June this year, some netizens broke the news that a Lantu FREE with a dark green body caught fire near a charging pile. Thick smoke was everywhere, flames were constantly spraying out of the vehicle's chassis, and the vehicle's engine hood, body and trunk door were all Opened.
From the photos taken at the scene, it can be seen that there are no obvious burn marks on the paint around the car body, and the tires and the bottom structure of the car body are relatively complete.
This month, some netizens claimed that on July 8, a fire broke out at a Tesla spray-painting center in Suzhou. From the photos circulated on the Internet, it can be seen that many Tesla cars were severely burned in the fire, and only the parts of the entire car were left. frame.
According to the "Daily Economic News" report, the cause of the fire at Tesla's Suzhou injection molding center may have been caused by a Tesla accident vehicle that was waiting to be repaired.
In addition, some car companies have recalled some models due to the risk of fire in hybrid vehicles.
According to CCTV Finance citing a Reuters report on April 3, a spokesperson for the German automaker Volkswagen Group stated that it will recall more than 100,000 plug-in hybrid vehicles globally due to the risk of fire.
The 100,000 vehicles recalled this time include not only Volkswagen brand models, but also Skoda, Audi and other models. Among them, the Volkswagen brand will recall 42,300 vehicles worldwide, and Audi will recall 24,400 vehicles.
On July 8, Ford announced that it would recall a new batch of 100,000 hybrid vehicles in the U.S. market due to the risk of fire. The new recalled models cover some models from 2020 to 2022, including Ford Escape, Maverick and Lincoln Corsair, all of which are equipped with 2.5-liter hybrid/plug-in hybrid engines.
According to Ford, if an engine fails, large amounts of engine oil and fuel vapors may be released and may accumulate near ignition sources, causing a fire.
So what is the reason why electric cars frequently catch fire?
Cause of fire:
The battery itself catches fire
High voltage module catches fire
Sanyan Finance consulted an industry insider, who said that there are two reasons why electric vehicles often catch fire. One is that the battery itself catches fire, and the other is that the high-voltage module catches fire.
According to an industry insider, unprovoked battery fires are generally caused by quality control problems, but now battery quality control is becoming more and more stringent, so unprovoked fires are rare and more often caused by chassis collisions.
Ternary lithium batteries will cause thermal runaway due to collision and extrusion, and then release oxygen. This is unsolvable, and the instantaneous temperature will reach more than five or six hundred degrees; while lithium iron phosphate blade batteries have low activity and better structural design, generally It will only smoke, not explode.
When a high-voltage module catches fire, the industry insider gave an example, just like sparks will be generated when high-voltage electricity hits iron. The same is true for high-voltage modules. As long as arcing occurs, it will catch fire when it comes into contact with flammable materials.
It seems that it will take time to perfectly solve the problem of electric vehicles easily catching fire.
But for now, even if it is easy to catch fire, in the event of an accident, can current electric vehicles leave enough time for the occupants to escape from danger?
There have been regulations for a long time: batteries must not catch fire within 5 minutes of thermal runaway.
But the ideal is full and the reality is skinny
In fact, relevant departments have also issued relevant regulations regarding the fact that electric vehicles are prone to catching fire.
On May 12, 2020, the Ministry of Industry and Information Technology issued three mandatory national standards for electric vehicles, which will be implemented from January 1, 2021.
Among them, the third "Safety Requirements for Power Batteries for Electric Vehicles" proposes that after a thermal runaway occurs in a battery cell, the battery system must not catch fire or explode within 5 minutes, leaving time for safe escape for the occupants.
When this regulation was introduced, CATL confidently stated that "the national standard is only the basic threshold, and CATL has higher requirements."
Zeng Yuqun, chairman of CATL, said that in terms of materials, the R&D team has developed highly stable cathode materials and highly safe electrolytes through atomic-level innovation. The high-temperature resistance limit of the battery has been increased by 40°C, and the thermal stability has been greatly improved.
As for the cell structure, a highly integrated and robust anti-internal short-circuit electrode is designed. The cell will not catch fire or smoke when subjected to various abuse tests.
In terms of battery pack design, we quantitatively analyze the damage to the battery core when the shell undergoes different elastic deformations and plastic deformations under the action of external forces, and optimize the structural strength of the battery pack.
Designs have been made in battery thermal management and system heat dissipation, claiming to reduce the risk of fire.
Regarding the new national standard for power batteries, which requires the system heat diffusion time to be no less than 5 minutes, Zeng Yuqun said that this is crucial to improving safety and ensuring the escape of personnel. However, the national standard is only the basic threshold, and the Ningde era has higher requirements.
As a domestic power battery giant, CATL’s customers naturally include Tesla, as well as traditional car giants such as SAIC, GAC, Geely, and Changan, as well as new entrants such as NIO, Ideal, Xpeng, WM, and Hezon Energy vehicle companies.
Considering Lin Zhiying’s accident, was the car owner given enough escape time to avoid catching fire after 5 minutes?
According to media reports, at about 10:51 a.m. on July 22, Lin Zhiying was driving a Tesla Model X toward Taoyuan on the Zhongzheng Bridge in Luzhu District, Taoyuan City, Taiwan Province of China when he hit the ramp isolation strip and the vehicle immediately caught fire.
The worker who rescued Lin Zhiying and his son recalled hearing a "bang" while working. He ran out within a minute or two and saw that the vehicle was already on fire. It may take less than 5 seconds to pull the person out, and the entire fire spread to the cab.
If what the workers who rescued Lin Zhiying and his son said is true, it is obvious that Tesla did not meet the national standards.
Although it cannot be concluded that all Tesla batteries are supplied by CATL, this also reflects the problems that some new energy car companies still have.
It is reported that Tesla vehicles are equipped with AEB (automatic emergency braking) function, which means that regardless of whether automatic driving is turned on or not, as long as the system detects that there is an obstacle ahead that is about to cause a collision, it will automatically brake to avoid danger. .
At the 2022 World Power Battery Conference, Sun Jinhua, an academician of the European Academy of Sciences and a professor at the University of Science and Technology of China, focused on the statistics of new energy vehicle fires.
It is reported that the data comes from the Fire and Rescue Bureau of the Ministry of Emergency Management.
In 2021, more than 3,000 electric vehicle fire accidents occurred across the country. Calculated based on the nearly 8 million pure electric vehicles in stock, the probability of catching fire is about 3 in 10,000; the annual fire accident rate of traditional fuel vehicles is about 1 in 10,000 One to two ten thousandths, lower than electric cars.
Judging from the battery types in fire accidents in 2019, 60% were ternary lithium batteries, 5% were lithium iron phosphate batteries, and 35% were unknown.
In general, whether it is a ternary lithium battery or a lithium iron phosphate battery, there is currently a risk of fire.
While major new energy vehicle companies are promoting how environmentally friendly electric vehicles are, should they also think about how to solve the problem of easy fires?
