Know the reason for the explosion of lithium batteries

1. Overcharge causes too much lithium to be released, and the negative electrode capacity is insufficient. The lithium appearing during charging cannot be inserted into the interlayer structure of the negative electrode graphite, and metallic lithium will be formed on the surface of the negative electrode. For a long time, lithium molecules will grow a net-like crystal structure from the negative surface layer to the lithium battery. This lithium metal crystal will pass through the diaphragm, causing a positive and negative short circuit failure. Sometimes the rechargeable battery explodes before the short circuit failure occurs, because the lithium battery electrolyte and other raw materials will destroy the steam, causing the battery sleeve or pressure valve to burst, allowing the carbon dioxide to react with the lithium atoms deposited on the negative surface layer, and then explode. 2. When the battery is charging, current limit is also necessary. When the current is too large, the lithium battery cannot catch up with the interlayer structure and will concentrate on the surface layer of the cathode material. This kind of lithium battery will have lithium ion crystals on the surface of the raw material, just like overcharging, which can lead to dangerous factors. Therefore, generally in the lithium battery pack, in addition to the lithium battery, there is also a lithium battery protection board, commonly known as bms (battery management system), and the Chinese name is rechargeable battery intelligent management system. It can test the lithium power supply in the event of interference based on the operating voltage, current and temperature information content of the lithium power supply. Regardless of whether it is a pure electric vehicle or an electric vehicle, lithium-ion safety accidents are not fresh. In the old national standard period, the electric vehicle industry has used a small amount of lithium ion, and many safety accidents have occurred. The key reason is that the lithium battery cell is unstable, the packaging and production technology is immature, and little is known about the use of lithium ion. With the increase in the amount of lithium ion used during the national standard period, if some countermeasures are not taken, the possibility of safety accidents is very high. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: What to pay attention to when using, storing and transporting polymer lithium batteries