低温条件下锂离子电池电、热性能研究

Study on Electrical and Thermal Properties of Lithium-ion Batteries at Low Temperature

锂离子动力电池系统在低温条件下能量密度和功率密度降低,影响车辆的动力性能和续航里程。针对此问题,文章选定电池供应商提供的锂离子电池模块,根据目前国标和实际工况对电池系统的要求,采用试验的方法得到了电池模块表面温度随不同环境温度、不同充放电状态以及行驶工况下的变化规律。结果表明,随着环境温度的下降,放电平台、放电容量都会变小,而温升会变大;在低温状态下放电平台会经历一个"波谷"阶段;为了保证低温下电池的正常使用,必须对电池进行热管理设计。本文研究结果可为动力电池系统结构设计和热管理设计提供技术支撑。

Under low temperature conditions the energy density and power density of the lithium-ion power battery system will be reduced,which affects the vehicle's dynamic performance and cruising range.In response to this problem,a lithium-ion battery module provided by the battery supplier is selected in this study.According to the current national standard and actual working conditions for the battery system,the surface temperature of the battery module is obtained for different ambient temperature,different discharge state and driving conditions.The results show that as the ambient temperature decreases,the discharge platform and discharge capacity will become smaller,and the temperature rise will become larger;in the low temperature state,the discharge platform will experience a "valley" stage.In order to ensure the normal use of the battery at low temperatures,thermal management of the battery is necessary.The research results in this paper can provide technical support for structural design and thermal management design of power battery systems.