Five major causes of explosions and fires of lithium-ion batteries

1. Insufficient capacity of the negative electrode of the lithium ion battery When the capacity of the negative electrode of the lithium ion battery is insufficient, the lithium ion atoms appearing during charging cannot be inserted into the interlayer structure of the negative electrode graphite, and will precipitate on the surface of the negative electrode and form crystals. Long-term formation of crystals in lithium-ion batteries can cause short circuits. At this time, the battery cells are discharged rapidly, and a lot of heat will appear, which will burn the diaphragm. High temperature will decompose the electrolyte into gas, and when the pressure is too high, the cell will explode. 2. The water content is too high. When the lithium ion battery is charged, the water can react with the lithium ions to generate lithium oxide ions, causing the capacity loss of the battery cell, and it is easy to cause the battery cell to be overcharged and generate gas, and the water is decomposed The voltage is low, and it is easy to decompose and generate gas when charging. These gases will increase the internal pressure of the battery. When the outer shell of the battery cannot withstand it, the battery will explode. 3. Internal short circuit The short circuit of the internal battery cell causes a large current discharge, a large amount of heat occurs, which burns the diaphragm, and causes a greater short circuit phenomenon, which will cause the electrolyte to decompose into gas, and the internal pressure is too high, and the battery cell will explode. Fourth, when the lithium ion battery is overcharged, the lithium ion of the positive electrode is excessively released, which will change the structure of the positive electrode. If the lithium ion is too much, it is easy to be unable to be inserted into the negative electrode, and it is also easy to cause lithium ions on the negative electrode surface. , When the voltage reaches 4.5V or more, the electrolyte will decompose and process a large amount of gas. All of the above may cause an explosion. 5. External short circuit The external short circuit may be caused by the wrong connection of the positive and negative electrodes. Due to 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 or completely destroy the diaphragm inside the battery core, causing an internal short circuit. , Which exploded. 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: What are the advantages and disadvantages of energy storage lithium-ion battery electric vehicles