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What are the main aspects of the safety of lithium batteries for electric vehicles?

What are the main aspects of the safety of lithium batteries for electric vehicles?


From the perspective of fuel vehicles, the safety performance of vehicles mainly includes active safety configuration and passive safety configuration. The so-called active safety configuration is to prevent accidents, and the passive safety configuration is to effectively protect passengers after an accident. From the perspective of pure electric vehicles, there are still many differences in the structure of fuel vehicles, so there will be many differences in safety configuration. So when choosing a pure electric vehicle, which safety configuration should be mainly considered?



First, the material of the battery.


Although most electric vehicles currently use lithium batteries, different models are equipped with different lithium batteries. From the point of view of battery materials, current electric vehicles are mainly based on ternary lithium batteries and lithium iron phosphate batteries. The safety performance of the two batteries in use is different. Lithium iron phosphate batteries can withstand punctures, short circuits, and will not ignite spontaneously after a collision. This is mainly because the electrode material of the ternary lithium battery has a high decomposition temperature. The electrode material of the ternary lithium battery will only decompose at 600 degrees Celsius, and it will not produce oxygen during decomposition, so it is relatively safe. better.



Second, battery thermal management


The role of power batteries in electric vehicles is crucial, but the current power batteries are more "precious" and sensitive to temperature. Like the current ternary lithium battery, the normal operating temperature is directly from 0 to 60 degrees Celsius, and it works best when the temperature is 10 to 35 degrees Celsius. If the battery temperature is too high, it is easy to cause battery thermal failure and battery spontaneous combustion, so how to control the battery temperature is very important. Like the current thermal management methods for batteries, there are mainly air-cooled, water-cooled, and direct-cooled methods, and the water-cooled technology is currently relatively mature.



Third, the battery protection configuration


Most of the current power batteries are installed on the chassis of the car, and they are more likely to collide in later use. Therefore, how to increase the safety performance of the power battery under collision is also very important. And this kind of protection configuration generally includes two kinds, one is to increase the hardness of the battery casing and add some mechanical protection measures. Another aspect is to increase the battery's control of the circuit after a collision. For example, Bosch has previously developed a power cable that can directly explode in the event of a collision, which can cut off the power battery during a collision to prevent short-circuit and spontaneous combustion of the power battery.


Summarize


In fact, whether it is a fuel car or an electric car, when choosing, in fact, we must pay more attention to the active safety configuration of the vehicle, which can effectively prevent accidents and increase the safety of the vehicle. The power battery of an electric vehicle is the most important unstable factor for an electric vehicle, so the safety of the power battery needs to be paid more attention when choosing an electric vehicle.