What are the important reasons for the burning and explosion of lithium batteries?

The most important thing for everyone now is to worry about the burning and explosion of lithium batteries. As far as the current lithium battery industry is concerned, the explosion caused by the main cause of the battery itself has been very, very low. After all, the factory has undergone tests such as aging and capacity separation. Unless it is a very low-level factory, the products of regular companies will not appear, so There is no need to discriminate against the types of batteries. However, the incentives caused by changes in external conditions are important, such as overcharging, overdischarging, external impact, high temperature, etc., so the current prevention method is to do a good job in line protection design, reasonable structure and other preventive measures. The purpose of posting is to tell everyone that when choosing a lithium battery, you must be cautious. First, you must have a full knowledge of the lithium battery you are about to use, and use it rationally. 1. When the lithium battery is heated, the reactions inside the battery are like a reaction chain, and each reaction promotes each other and proceeds in sequence. The first is that the SEI film releases heat to heat the lithium battery, which promotes the reaction between the negative electrode and the solvent to release more heat, leading to the reaction between the negative electrode and the binder and solvent decomposition, and then the positive electrode begins to undergo thermal decomposition reaction, releasing a large amount of heat and The gas eventually causes the lithium battery to burn or explode. 2. In the initial stage of lithium battery charging, part of the electric energy is converted into heat when the current passes through the battery, and part of the heat also appears in ohmic polarization, but the surface temperature of the lithium battery rises very slowly; when the battery reaches a fully charged state, the lithium ions continue to be inserted The reaction becomes the deposition of lithium metal on the surface of the negative electrode, and the solvent is oxidized (the heat released by the oxidation reaction of the solvent caused by overcharge is much higher than the heat released by the reaction between lithium ions and the solvent in the reversible state), and the heat released heats the battery; As the temperature of the lithium battery increases, the reaction of metallic lithium with the solvent and the reaction of the lithium-intercalated carbon with the solvent occur successively, and the heat is out of control. At the same time, the decomposition of the solvent and the reaction between the binder and the lithium metal occur. 3. The harm caused by short circuit, needle stick and impact to lithium battery is roughly the same. When a short circuit occurs, a large amount of heat occurs when the current passes through the battery, which heats the battery and raises the temperature of the battery to the temperature at which the positive electrode decomposes. The thermal decomposition of the positive electrode causes the battery heat to run out of control. A short circuit and a large amount of heat increase the internal temperature of the lithium battery to the temperature at which the positive electrode is thermally decomposed; when the lithium battery is impacted, the overvoltage loss on the electrode will cause heat to promote the reaction between the solvent and the negative electrode, and the heat released will further heat the battery , Which promotes the thermal decomposition reaction of the positive electrode to occur, causing the heat to run out of control. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.