The frequent fire accidents of electric vehicles have exposed some new problems in the field of power batteries.In early August, an electric car-hailing spontaneous combustion accident occurred in Dalian. According to local media reports, it was initially understood that the accident was a battery fire.In July, there were 14 electric vehicle fire accidents that can be counted in the country, and 12 of them have clear time and place information.
Fire accidents occur frequently, revealing some different situations from previous years, which are worthy of industry attention.
According to the analysis of the cause of the recent fire accident by the National New Energy Vehicle Accident Investigation Expert Group, there are mainly two categories:
One category is obvious product design flaws. The other type is non-product design defects, which are mainly concentrated in the short product verification cycle, incomplete safety verification system, insufficient product safety boundary setting, use and charging process.
In the tracking of fire accidents, there are fewer and fewer reasons for product design defects in the first category, and more and more reasons in the second category, especially the problems in the specific use process, which are often ignored.
Charging safety is also an important aspect of active safety control.
At present, the proportion of accidents in charging is relatively high. From the perspective of mechanism, thermal runaway is most likely to occur during fast charge, full charge, or overcharge, especially when the problem of lithium evolution during charging causes thermal runaway. Because charging is not only about batteries, but also related to cars, chargers, and charging stations. In the next few years, charging control will gradually develop into subdivided industries to attract attention.
In addition, there is safety throughout the life cycle, the premise of which is an accurate estimation of the state of health.
Many people in the industry, including Ouyang Minggao, believe that artificial intelligence, big data, and cloud platforms can be introduced in active safety to improve the technical level of battery management, battery early warning, battery charging control, and battery life prediction and evaluation. If these are implemented well, the life cycle safety of the high nickel ternary battery of 300Wh/Kg battery is expected to be solved within two years.
Post time: Sep-07-2020