What is the cause of thermal runaway caused by power lithium-ion battery

As the energy source of pure electric vehicles, the important reason for the fire of lithium-ion batteries is the thermal runaway caused by overheating of the battery. This overheating is most likely to occur during the charging and discharging of the battery. Because the lithium-ion battery has a certain internal resistance, a certain amount of heat will appear while outputting electric energy to supply power for pure electric power, making its own temperature higher. When its own temperature exceeds its normal operating temperature range, it will damage the entire battery. Longevity and safety. Causes of thermal runaway: The first category is external factors of the battery. If the ambient temperature of the battery is too high, the battery heat dissipation is not good, or the internal winding is not good, resulting in poor heat dissipation of the battery. In addition, there is another situation that the company should pay special attention to, that is, the battery spine can sometimes introduce heat. The metal spine of the battery has copper and aluminum, and the thermal conductivity is relatively good. There are some components with high heat sources in the circuit. , Be sure to stay away from the battery spine to let the heat fully play. Qiu Xinping added. The second category is the internal factors of the battery. One is micro short circuit. There are two cases of micro short circuit. One is short circuit in battery technology, including burrs; the other is short circuit during use. These will cause micro short circuit and cause the local temperature of the battery to be higher than the thermal runaway temperature. As a result, thermal runaway occurs. The third is that the battery is overcharged, which will reduce the thermal runaway temperature of the material after overcharge. For example, the capacity of the battery has decayed in the middle and late stages of use. At this time, the battery itself is already in an overcharged state, and the thermal runaway temperature will naturally drop. Qiu Xinping pointed out. The fourth is the amount of electrolyte. If the amount is too much, the explosion will be very harmful, and the flame will spray very high and far, so the amount of electrolyte must be strictly controlled. 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: What are the characteristics of the retired power lithium battery?