3 major causes of fire in lithium-ion batteries

Due to the abuse of the battery, such as the branch crystal caused by overcharge and overdischarge, the impurities and dust in the battery processing, etc., it will deteriorate to pierce the diaphragm, cause a micro short circuit, and the release of electric energy will cause temperature rise, and the material chemistry caused by the temperature rise The reaction expands the short-circuit path and forms a larger short-circuit current. This mutual accumulation of mutually reinforcing damage leads to thermal runaway. 2. Take electric vehicles as an example for external short circuits. The probability of danger in actual vehicle operation is very low. One is that the vehicle system is equipped with fuses and a battery management system BMS, and the other is that the battery can withstand a short-term high current impact. In the extreme case, the short-circuit point crosses the vehicle fuse, and the BMS fails. A long-term external short-circuit will generally cause the weak points in the circuit to be burned, and rarely cause thermal runaway events in the battery. Now, more PACK companies have adopted the method of adding fuses in the loop, which can more effectively prevent the hazards caused by external short circuits. 3. Due to the characteristics of the structure of the lithium ion battery, the SEI film, electrolyte, EC, etc. will undergo decomposition reactions at high temperatures. The decomposition products of the electrolyte will also react with the positive and negative electrodes, and the battery diaphragm will melt and decompose. The reaction causes a lot of heat to appear. The melting of the diaphragm causes an internal short circuit, and the release of electrical energy increases the heat processing. This cumulative and mutually reinforcing destructive uses will result in the explosion of the explosion-proof membrane of the battery cell, the ejection of the electrolyte, and the occurrence of combustion and fire. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: How to maintain the power lithium-ion battery in winter?