What are the reasons for the basic explosion of lithium batteries?

Due to the internal short-circuit phenomenon, the battery core discharges with high current, a lot of heat occurs, which burns the diaphragm, and causes a greater short-circuit phenomenon, so that the battery core will have a high temperature, causing the electrolyte to decompose into gas, causing excessive internal pressure. When the shell of the battery cell cannot withstand this pressure, the battery cell will explode. During laser welding, heat is conducted to the positive electrode ear through the shell, making the temperature of the positive electrode ear high. If the upper adhesive paper does not separate the positive electrode ear and the diaphragm, the hot positive electrode ear will burn or shrink the diaphragm paper, causing an internal short circuit. And it formed an explosion. 2. When the customer spot welding the negative ear with high-temperature adhesive paper, heat is conducted to the negative ear. If the high-temperature adhesive paper is not attached properly, the heat on the negative ear will burn the diaphragm, causing an internal short circuit and an explosion. 3. If the bottom glue is not completely covered by the bottom, when customers spot welding at the bottom aluminum-nickel composite tape, a lot of heat will appear on the bottom shell wall, which will conduct the bottom of the pole core. If the high temperature adhesive tape does not completely cover the diaphragm, it will burn. The diaphragm is broken, causing an internal short circuit and an explosion. 4. If the moisture content is too high, the moisture can react with the electrolyte in the cell, process gas, and when charging, it can react with the generated lithium to generate lithium oxide, which will cause the loss of the capacity of the cell, and the cell will be overcharged. Generate gas, the decomposition voltage of water is low, and it is easy to decompose to generate gas when charging. When this series of generated gas will increase the internal pressure of the battery, when the outer shell of the battery cannot withstand it, the battery will explode . 5. Insufficient negative electrode capacity. When the negative electrode part opposite the positive part has insufficient capacity or no capacity at all, part or all of the lithium batteries 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. , Forming protruding dendrites, and the next charging, this protruding part is more likely to cause the precipitation of lithium. After tens to hundreds of cycles of charging and discharging, the dendrites will grow up, and finally pierce the diaphragm paper to make the inside There is a short circuit. When the shell of the battery cell cannot withstand this pressure, the battery cell will explode. 6. The battery core is overcharged for a long time. The battery is overcharged for a long time. Overcharge and overcurrent will also cause high temperature and high pressure, which may cause hidden dangers. Lithium batteries may instantaneously discharge under special conditions of temperature, humidity, and poor contact, resulting in a large amount of current, spontaneous combustion or explosion. 7. External short-circuit The external short-circuit may be caused by improper operation or misuse. Due to the external short-circuit, the battery discharge current is large, which will cause the battery core to heat up, and the high temperature will shrink the diaphragm inside the battery cell or completely break it, causing the internal Short circuit and explode. 8. Thermal runaway lithium battery has the risk of explosion because of a process called thermal runaway in the reaction inside the battery. 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 article: What is the reason for the capacity decline of the lithium battery?