Optimization of the Heat Dissipation Structure for Lithium-Ion Battery Packs Based on Thermodynamic Analyses

The battery thermal management system plays an important role in electric vehicles, and determines the performance and the lifespan of electric vehicles. In this paper, optimization of the heat dissipation structure of lithium-ion battery pack is investigated based on thermodynamic analyses to optimize discharge performance and ensure lithium-ion battery pack safety. First, the heat generation and heat transfer model of the lithium-ion battery cell are derived based on thermodynamic theory. Then, the thermodynamic governing equations of battery are established based on Fluent, and the model is verified by comparing simulation data and experimental data. Afterwards, the simulation model of pure electric vehicles and the model of the heat generation rate are established using ADVISOR to analyze the dynamic performance of the battery pack. Finally, the air-cooling structure of the battery pack is designed according to the temperature field distribution obtained from the Fluent simulation, which is optimized using a back propagation neural network combined with genetic algorithms for the air flow rate, air flow channel spacing between cells, and air inlet angle. Based on the results of the optimized structure, the optimized structure effectively increases the heat dissipation performance and eliminates temperature inconsistency between the cells.