What are the common causes of fire in lithium batteries?

The common causes of fires in lithium batteries are mainly as follows. Insufficient capacity of the negative electrode When the capacity of the negative electrode opposite to the positive electrode is insufficient or has no capacity at all, part or all of the lithium generated during charging cannot be inserted into the interlayer structure of the negative electrode graphite, and will be deposited on the surface of the negative electrode to form protrusions. In the next charge, this protrusion is easier to form lithium precipitation. After tens to hundreds of cycles of charging and discharging, the dendrites will grow up and eventually pierce the barrier paper, causing internal short circuits. The battery core discharges rapidly, and a lot of heat occurs, which burns the barrier and forms a larger short circuit. High temperature will cause the electrolyte to split into gas, and the negative carbon and barrier paper are burned, resulting in excessive internal pressure. When receiving this pressure, the battery cell will burst. If the moisture content is too high, the moisture can react with the electrolyte in the battery cell and produce gas. When charging, it can react with the generated lithium to generate lithium oxide, which will cause the capacity of the battery cell to be lost, and it is easy to overcharge the battery to generate gas. The differentiation voltage of water is low, and it is easy to differentiate into gas when charging. When this series of generated gas will increase the internal pressure of the cell, when the shell of the cell is unacceptable, the cell will burst. Internal short circuit occurs because of the internal short circuit phenomenon, the battery core discharges with a large current, a lot of heat occurs, the barrier is burned, and a larger short circuit phenomenon is formed, so that the battery core will have a high temperature, which will cause the electrolyte to split into gas and form an internal pressure. When the outer shell of the battery cell cannot accept this pressure, the battery cell will burst. 4 When the overcharge core is overcharged, the excessive release of lithium in the positive electrode will change the structure of the positive electrode, and the released lithium will simply not be inserted into the negative electrode, and it will also simply form the surface of the negative electrode to precipitate lithium, and when the voltage reaches 4.5V or more At this time, the electrolyte will differentiate and produce a lot of gas. All of the above may form a blast. 5 External short-circuit The external short-circuit may be caused by improper operation or misuse. Because of the external short-circuit, the battery discharge current is very large, which will cause the battery core to heat up, and the high temperature will shrink the internal barrier of the battery cell or completely destroy it, forming an internal Short circuit, so blasting. 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 are the differences between UPS power batteries and UPS lithium batteries?