How to Ensure Battery Safety in Extreme Collisions

The May 26th accident in Shenzhen severely affected the reputation of the domestic electric vehicle brand, BYD, as their battery safety became deeply questioned. The incident involved a red GTR sports car colliding with two taxis on the Binhai Avenue. One of the taxis caught fire, killing the driver and two passengers. The burning taxi was a pure electric vehicle, BYD's E6, which caused BYD's stock price to drop and lost over 5.7 billion yuan in market value.

A review of events: When BYD launched the E6 model last year, the company publicly demonstrated the battery factory and a series of safety tests performed on their battery, including extreme conditions such as compression, piercing, collisions, and fire. At the time, BYD claimed that after 50 vehicles underwent 24-hour road tests in their test facility under extreme environments, the safety of the E6 was well ensured. However, the incident involving the first domestic pure electric car fire, resulting in passenger deaths, once again raised questions about the safety of lithium batteries.

Impact on the Electric Vehicle Industry in Dongguan

Dongguan, which is also promoting the demonstration application of pure electric vehicles, planned to launch 320 new energy vehicles this year, including 50 pure electric vehicles (40 pure electric minibuses and 10 pure electric sedans). Will this accident slow down Dongguan’s electric vehicle industry? Wang Zhaohong, spokesperson and deputy director of the Dongguan Development and Reform Bureau, stated, “The cause of the BYD accident has not been officially determined and announced, but Dongguan will continue to develop the electric vehicle industry according to the industrial route, while paying more attention to the safety of electric vehicles.”

Among the 10 pure electric sedans planned for launch in Dongguan, 5 are developed and manufactured by the Dongguan Zhongshan University Research Institute, a technology platform for electric vehicle lightweight and overall R&D established in Songshan Lake.

Zong Zhijian, vice president of the Zhongshan University Dongguan Research Institute, stated that the "526 car accident" had prompted reflection within the industry. "Undoubtedly, BYD's accident has had a huge impact on the entire electric vehicle industry and R&D, but we are striving to learn from this and avoid such tragedies in the future." Zong acknowledged that under current technology conditions, the safety performance of electric vehicle batteries in extreme conditions like crashes is still a challenge.

Ensuring Battery Safety in Extreme Collisions

Zong Zhijian explained that lithium batteries are inherently one of the safest options. Electric vehicle lithium batteries must undergo abuse testing to simulate various extreme environments, such as water immersion, fire, insertion of foreign objects, compression, etc., and lithium batteries can remain stable under these tests. According to the Ministry of Industry and Information Technology’s 203rd batch of the “Announcement on Vehicle Manufacturers and Products,” the BYD E6 model’s battery has passed compression tests by national authoritative agencies. After 50% deformation of the battery module, there was no fire.

However, why did the battery ignite in this accident? Zong explained, "Compression at a certain speed is still very different from a high-speed crash at over 100 km/h. In a short period, most of the battery and the car body are compressed together due to the high-speed collision, leading to a short circuit and other issues. Honestly, we haven’t overcome this in our experiments."

How to Ensure Battery Safety in Extreme Impact Situations

"When the fuel tank of a gasoline-powered car is compressed, it also generates similar dangers, like igniting gasoline, which can cause an explosion. But there is a clear difference: gasoline will not ignite unless exposed to fire, whereas in electric vehicles, after being impacted, the circuit may short-circuit. Once a short circuit causes a spark, it is highly likely to trigger an explosion of the battery," Zong Zhijian explained. This is a global issue that is currently unsolved.