What are the important functions of the power lithium battery thermal management system?

The function of the power lithium battery thermal management system will directly affect the service life and performance of the power lithium battery due to excessively high or low temperature, and may cause safety problems in the battery system, and the long-term uneven distribution of the temperature field in the battery box It will cause imbalance in the performance of the battery modules and cells. Therefore, the battery thermal management system is necessary for the power lithium battery system of electric vehicles. Reliable and efficient thermal management systems are of great significance to the reliable and safe application of electric vehicles. The battery pack thermal management system has the following five important functions: ①Accurate measurement and monitoring of battery temperature. ② Effective heat dissipation and ventilation when the battery pack temperature is too high. ③Rapid heating under low temperature conditions. ④ Effective ventilation when harmful gases appear. ⑤Ensure the uniform distribution of the temperature field of the battery pack. The basic method of heat transfer in the battery There are three important methods of heat transfer in the battery: heat conduction, convection heat exchange and radiation heat exchange. The heat exchanged between the battery and the environment is also carried out in three ways: radiation, conduction and convection. Thermal radiation mainly occurs on the surface of the battery and is related to the properties of the battery surface material. Heat conduction refers to the heat transfer that occurs when a substance is in direct contact with an object. The electrodes, electrolyte, current collector, etc. inside the battery are all heat-conducting media, and the battery as a whole, the temperature of the interface layer between the battery and the environment and the environmental heat conduction properties determine the heat conduction in the environment. Thermal convection means that the heat on the battery surface exchanges heat through the flow of the environmental medium (usually fluid), and it is also proportional to the temperature difference. Regarding the inside of a single battery, the influence of heat radiation and heat convection is small, and the transfer of heat is importantly determined by heat conduction. The amount of heat absorbed by the battery itself is related to the specific heat capacity of the material. The larger the specific heat capacity, the more heat dissipation, and the smaller the temperature rise of the battery. If the heat dissipation is greater than or equal to the heat that occurs, the battery temperature will not rise. If the heat dissipation is less than the heat generated, the heat will accumulate in the battery body and the battery temperature will rise. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.