Iron battery that would rather die

On the morning of August 3, the Shenzhen Institute of Metrology Quality Inspection informed the “5.26” traffic accident quality assessment of the pure electric taxi. The form and severity of the 5.26 traffic accident was extremely rare; the e6 taxi battery did not explode, and the entire vehicle was designed for safety. No defects, not only through the national tests, but also in line with the United States FMVSS standards. BYD Co., Ltd. subsequently issued an announcement on the results of the assessment.

No defect: the most severe identification of 13 experts

The appraisal was organized by Shenzhen Metrology and Quality Inspection Research Institute, and invited domestic electric vehicles for complete vehicles and power systems, component safety, structural safety, collision safety, electrical and electronic safety, electric vehicle battery, automobile traffic accident identification, fire investigation, and materials 13 experts in the field of combustion characteristics and other experts form a group of experts, among which there are 3 experts from Guangdong Province and 10 experts from other provinces. Experts came from the China Automotive Technology and Research Center, the Ministry of Transport Highway Research Institute, the Ministry of Public Security Tianjin Fire Research Institute, the Guangdong Provincial Fire Corps, the Northern Vehicle Research Institute, Shenzhen Metrology and Quality Inspection Institute and other technical agencies. Among them, the head of the quality assessment expert group is deputy director of China Automotive Technology and Research Center, chairman of the National Automobile Standardization Technical Committee Electric Vehicle Sub-Technical Committee, and Wu Zhixin, general expert of the “Energy-saving and New Energy Vehicle” major project of the Ministry of Science and Technology 863 Program. Served as The expert group carried out special quality appraisal on five aspects such as the entire vehicle, vehicle collision, power battery, fire and traffic accident identification. The entire appraisal work lasted for about two months.

The results of the appraisal showed that the sports car at the time of driving was about 242km/h, and after braking, the e6 pure electric taxi with a speed of about 183km/h and the same direction in front, and a speed of about 81km/h, collided and crashed. When the two vehicles relative speed exceeds 100km/h. After the collision, the e6 pure electric taxi lost control and slipped to the right front. There was a serious "column collision" between the tail and the roadside trees. The incursion amounted to 1050mm, causing damage to the e6 pure electric taxi, three deaths, and the vehicle caught fire. Severity is extremely rare. In two serious collisions, the three passengers in the electric taxi suffered mechanical injuries that exceeded the limit of the human body and caused fatal injuries to three passengers.

Due to the impact of two serious collisions, the rear part of the e6 body and the battery tray were severely deformed, and a short circuit between the high voltage circuit in the high voltage distribution box and the vehicle body resulted in arcing, ignition of interior materials and some of the battery and other combustible substances. However, the e6 taxi battery did not explode in the entire accident, and 72 single cell batteries (75% of all 96 power cells) did not burn. The installation layout, insulation protection and high-voltage electrical system design of the power battery system in the vehicle are reasonable. There is no defect in the safety design of the vehicle.

Ning does not die: BYD "iron battery" is safe and reliable

Experts said that in extremely rare collisions, with 30 minutes of fire, half an hour of flooding (fire and rescue), and sun drying at the depot, there are still 72 single cell batteries (accounting for 75% of all batteries) in the e6. Undamaged and still usable. The 24 single cell batteries (25% of all batteries) involved in the combustion, the aluminum alloy case and the battery plate were partially burned, but the battery plate remained neat, well structured, and there was no popping phenomenon. Explain that BYD battery technology has high security and stability.

BYD e6 taxi uses BYD's self-developed "iron battery," namely, lithium iron phosphate battery. According to relevant data, this kind of battery has better performance in energy storage, high power, and over-charge and over-heat, and it is not easy to burn, and it will not explode. And it will not cause any pollution to the environment. In addition to BYD, GM also said that it plans to use lithium iron phosphate batteries for electric vehicles. The accident once caused the media to be skeptical about lithium iron phosphate batteries, but the results showed that the lithium iron phosphate battery has good safety and stability. BYD also said that in the research and development process, it has repeatedly burned “iron batteries”. Extreme tests such as squeezing, acupuncture and other tests have shown that iron batteries perform well. In an interview with the media, Prince Dongdong, director of the National 863 Electric Vehicle Major Special Power Battery Test Center, confirmed: “We had done a squeeze test on the battery module of the e6 electric vehicle. The test was equivalent to a 50-km-per-speed collision. E6 did not catch fire."

A foreign-brand executive who is very active in this field also expressed "goodwill" for BYD's iron battery project. He even suggested that BYD can separate the battery business to support it when it is difficult to rapidly popularize domestic electric vehicles in the short term. Whether this proposal is feasible or not, it at least shows BYD's technological leadership in the field of new energy vehicle batteries.

Doubt doubts: China's new energy should take a big step forward

The authoritative report given by the experts affirmed the safety and stability of BYD's battery technology, eliminating the doubts of all walks of life regarding the technology and development prospects of BYD electric vehicles and Chinese new energy vehicles. As a strategic product of leading brands for new energy vehicles, BYD e6 is the purest electric vehicle with the longest driving range in the world. The e6 single charge can travel up to 300 kilometers under comprehensive conditions, which is much higher than similar products in the world. As of the end of July, the cumulative total mileage of the 300 pure electric e6 taxis that have been put into operation in Shenzhen has approached 25 million kilometers, and the maximum mileage of bicycles has exceeded 220,000 kilometers, which is equivalent to the 10-year mileage of ordinary private cars. Its advanced performance and product stability are obvious.

The advanced nature of e6 is also reflected in the safety aspect. The expert group stated that the power battery cells, battery modules, and battery systems used in BYD's e6 electric vehicles all adopt the necessary safety design and multiple safety protection measures, and the system insulation protection and high voltage circuits System design is reasonable. It also confirmed that the e6 pure electric taxi was the product of the National Automobile New Product Announcement, and passed the tests of the vehicle collision safety, system electrical safety, and battery safety of the relevant national testing agencies, and the safety satisfies the “occupant protection for frontal collision of passenger vehicles”. , "Crew Protection for Side Impacts", "Safety Requirements for Electric Vehicles", "Li-ion Battery for Electric Vehicles" and other national standards. What is more worth mentioning is that the e6 pure electric vehicle has also been verified according to the US FMVSS standard, US-NCAP and IHSS test conditions of the American Insurance Association, and also meets the requirements of ECE R100. It can be said that e6 has "double insurance" in China and the United States in terms of security.

BYD said that it will further strengthen its R&D and promotion of electric vehicles based on its existing advantages, so that new products will have better performance and higher safety. Industry insiders also believe that we should believe that China has world-leading technology in the field of pure electric vehicles, and should not be held back by individual extreme events and misunderstandings of new energy vehicles, which will affect the development of the entire industry.