Heating Detection and Temperature Control Method of Power Lithium Battery in Pure Electric Vehicle

For the power battery of electric vehicles, especially pure electric vehicles, there is no perfect and comprehensive detection system and management system in the production and use links. By analyzing the working principle, structure and electrochemical characteristics of lithium-ion battery, the heat generation mechanism of lithium-ion battery was studied. In this paper, the factors that affect the temperature characteristics of Li ion battery are described, and the corresponding relationship between the temperature rise of the battery and the ambient temperature is established. At the same time, the optimal temperature range of the battery pack discharge efficiency is determined. In this paper, the thermal effect model and heat generation rate model of lithium-ion battery are established, and then the thermal conductivity, specific heat capacity, density and other parameters of the thermal model are calculated. Finally, the initial and boundary conditions of the thermal model are determined, the simulation of heat generation temperature field is realized, and the temperature distribution of the battery after heat generation is obtained. In this paper, the flow mode of air is analyzed, and the fluid structure coupling model of battery air is established. Finally, the thermal field of the battery pack is simulated by setting the solver mode and boundary conditions, which makes a theoretical analysis for the preliminary design of the temperature control battery box. The test results show that the method proposed in this paper can meet the technical requirements of power lithium battery heating management of pure electric vehicles..