Study On Thermal Characteristics Of Aircraft Lithium-ion Battery

With the continuous improvement of aircraft technology,the onboard electronic load has increased significantly,and the importance of aircraft power systems has increased to new heights.The aircraft battery as the last energy source needs provide power for aircraft’s important equipment to ensure flight safety in an emergency state,the performance of the battery directly affects the flight safety.Temperature is one important factors affecting the performance of the battery,massive heat is generated in the power supply process,if effective thermal management measures are not taken,the battery will be at a high temperature,which not only affect the battery performance and service life,but also affect the flight safety.Therefore,it is important to study the thermal characteristics of the battery and optimize the heat dissipation of the battery pack.Based on the analysis of the aircraft lithium-ion battery system and the working principle,working characteristics of lithium-ion battery,the lithium cobaltate battery with model ICP45 is selected as the research object,and the thermoelectric coupling model of the battery is established for the study of thermal characteristics.Firstly,the Thevenin equivalent circuit model is established,and the battery charge and discharge model is also built in Matlab/Simulink in order to explore the charge and discharge performance of the battery at different temperatures and the optimum working temperature range of the battery.Secondly,the thermal model of the single-cell lithium-ion battery and battery pack are built in SolidWorks,the parameters are determined,such as battery density,specific heat capacity,heat source and thermal conductivity.After coupling the equivalent circuit model parameters and thermal model parameters in UDF,the thermal characteristics of the battery are studied in Fluent.In view of the phenomenon that the temperature of the monomer and module exceeded the optimum temperature range,the phase change cooling method is adopted to heat the battery pack in order to reduce the maximum temperature and the temperature difference.Finally,the temperature of the battery is controlled in the optimum working temperature range.