Research On Heat Dissipation Characteristics Of Lithium-ion Power Battery Based On Heat Pipe

New energy has gradually become an emerging pillar of the automotive industry,of which electrification is a major branch.As the power component of electric vehicles,the performance and safety of power batteries directly affect the overall performance and safety of electric vehicles.For power batteries,the thermal management system has a crucial impact on its working performance and safety.If a large amount of heat generated by the power battery during the work process cannot be efficiently dissipated timely,the temperature of the battery will rise rapidly.Excessive temperature will not only affect the performance and cycle life of the battery,but may also cause the power battery to ignite or even explode.In order to improve the safety of the power battery at work,it is necessary to perform effective thermal management on the power battery.At present,the methods of battery thermal management for electric vehicles are mainly air-cooling and liquid-cooling systems.Phase change material cooling and heat pipe cooling rely on the high thermal conductivity of the phase change material and the excellent isothermal properties of the heat pipe to effectively improve the temperature consistency of the battery pack.They are efficient heat dissipation methods that can become a new generation of battery thermal management system in the future.Based on theory,this paper uses a method combined of simulation and experiment to research the temperature characteristic of the lithium-ion battery.Starting from the structure,heat generation mechanism,and heat transfer characteristics of lithium-ion batteries,a one-dimensional layered finite-difference thermal mathematical model for lithium-ion power batteries was established,and the temperature characteristics of the battery cells were simulated and verified by experiments.Then heat transfer and heat dissipation problems of the heat pipe cooling system are explained and analyzed,the corresponding heat transfer and heat dissipation models are established,and then a battery pack-flat heat pipes-fin thermal management system is constructed.The effects of natural air cooling and heat pipe cooling system on the heat dissipation characteristics and temperature uniformity of the battery module under different discharge rates and different ambient temperatures are studied through simulation.It shows,when the battery module is discharged at different rates and different ambient temperatures,the flat heat pipe cooling system can make the wall temperature of the power battery not higher than 45 ° C;The maximum temperature difference of the cell wall is 3.81 ℃,and the temperature difference between the battery cells is not higher than 4 ℃.The heat pipe used for the thermal management of lithium-ion power battery module,can not only greatly reduce the maximum temperature of the battery pack,but also improve the temperature uniformity between the battery cell and the cell itself,providing a reference for the heat pipe cooling system used in the electric vehicle power battery thermal management system.