Explain the culprit that caused the explosion of lithium-ion batteries

Refers to the outside of the battery cell, including short circuits caused by a series of factors such as poor internal insulation design of the forklift group. It may also be caused by improper operation. If a short circuit occurs on the outside of the battery cell and the electronic components do not cut off the circuit, the battery's discharge at this time will cause the battery temperature to rise, and the excessively high temperature will cause damage or direct damage to the diaphragm inside the battery cell. It leads to the shortness of the inside and the explosion we fear most! Internal short circuit: Once the internal short circuit occurs, a large amount of current will be discharged from the lithium ion battery pack of the forklift, a large amount of heat will be generated, and a large amount of gas will be formed inside, which will cause the internal pressure to be excessive, and when this pressure reaches the cell shell It will explode when it can't bear it! Overcharge: When the battery cell is overcharged, it may cause the positive lithium ions to be excessively released, which will cause the battery structure to change. If the negative lithium ions are not inserted into the negative electrode, it will also cause the surface of lithium ions to evolve. When the voltage reaches 4.5V or more, The electrolyte will decompose and process a large amount of gas. Overcharge may cause various dangerous situations such as leakage, deformation, fire, etc., and in serious cases, it may cause explosion! At present, for the problem of flammability of electrolyte, I have analyzed some solutions in previous articles, such as using solid electrolyte and developing solid-state lithium-ion battery, but its cost is relatively high. In addition, there is the use of new energy supply methods, such as the use of human kinetic energy to supply energy to electronic devices, which is still in the laboratory stage. Another very straightforward method is to add flame retardants to the existing electrolyte. However, in order to achieve flame retardancy, a large amount of flame retardant must be added to the electrolyte, which will correspondingly reduce the ionic conductivity of the electrolyte and significantly affect the electrochemical performance and energy density of the lithium ion battery. Innovation Recently, researchers at Stanford University in the United States have created a new type of intelligent electrostatic spinning separator, which has a heat trigger mechanism and contains a flame retardant inside that can be used to prevent the burning of lithium-ion batteries. In this structure, the flame retardant is packaged inside the polymer protective shell to prevent the flame retardant from directly dissolving into the electrolyte, thereby negatively affecting the battery performance. When the heat inside the lithium-ion battery is too high, the polymer protective shell will dissolve due to the high temperature and release the flame retardant, thereby effectively inhibiting the burning of the highly flammable electrolyte. 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: Explain the repair method and principle of 18650 lithium ion battery