液冷锂电池热管理系统性能与电池热物性特征耦合分析

Coupled analysis of performance and battery thermal properties of liq‐uid cooled lithium ion battery thermal management syst

温度是影响锂离子电池安全性及电化学性能的重要因素。设计高效的电池热管理系统对锂离子电池进行温度控制,是确保电池安全性、提升电化学性能的关键。构建了基于液冷的圆柱形锂离子电池组热管理模型,采用数值模拟的方法分析了冷却工质入口流速、电池冷却面积等系统参数以及电池径向热阻等电池自身参数对系统冷却性能的影响。结果表明:冷却工质流速增大,在提高电池冷却性能的同时也会导致系统压降大幅提高而降低系统经济性;通过增加冷却块数目或者冷却块高度的方式均可以提高电池冷却面积,前者效果更优;在相同冷却面积下,采用高度较小而数量较多的冷却块,能够实现多点冷却,从而提高电池模组温度均匀性;锂离子电池散热性能由电池内部导热热阻主导,提高电池径向热导率能够显著降低电池最高温度并提高其温度均匀性。因此,电池热管理系统的设计,必须综合考虑冷却系统参数、电池热物性参数以及电池运行情况,以确保电池组及热管理系统安全、高效、稳定运行。

Temperature is an important factor that affects the safety and electrochemical performance of lithium ion batteries.Designing an efficient battery thermal management system for temperature control is crucial for ensuring battery safety and improving electrochemical performance.In this paper,a thermal management model for cylindrical lithium-ion battery packs based on liquid cooling was constructed.Numerical simulation was used to analyze the effects of system parameters such as coolant inlet flow rate,battery cooling area,and battery radial thermal resistance,as well as battery specific parameters on the cooling performance of the system.The results show that increasing the coolant flow rate can improve the battery cooling performance,but it can also lead to a significant increase in system pressure drop and reduce system economy.Increasing the number of cooling blocks or the height of cooling blocks can improve the battery cooling area,with the former being more effective.Additionally,under the same cooling area,using cooling blocks with smaller height and larger quantity can achieve multi-point cooling and improve the temperature uniformity of the battery module.The heat dissipation performance of lithium-ion batteries is mainly affected by the internal thermal resistance,and increasing the radial thermal conductivity of the battery can significantly reduce the maximum temperature of the battery and improve its temperature uniformity.Therefore,when designing a battery thermal management system,it is necessary to consider cooling system parameters,battery thermal properties,and battery operating conditions to ensure the safe,efficient,and stable operation of the battery pack and the thermal management system.