动态工况下锂电池组多物理场仿真与退化分析  

Multi-physical Simulation and Degradation Analysis of Lithium-ion Battery Pack under Dynamic Conditions

作　　者：夏权 任羿[1] 孙博[1] 杨德真[1] XIA Quan;REN Yi;SUN Bo;YANG De-zhen(Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学,北京100191

出　　处：《装备环境工程》2023年第6期108-116,共9页Equipment Environmental Engineering

基　　金：国家自然科学基金(52075028);中国博士后科学基金(2021M690298)。

摘　　要：目的提高锂电池组SOH评估的准确性,提出面向实际复杂动态工况的锂电池组退化仿真分析方法。方法通过耦合多个电池单体P2D电化学–热模型和电池组串并联等效电路–热–流体模型,建立锂电池组多物理场耦合仿真模型,分析电池系统实际使用过程中电流、温度等工况的动态特性,构建锂电池组广义动态工作载荷谱。开展模型验证和典型3并5串锂电池组多物理场仿真分析,并耦合基于SEI膜生成机理的容量退化模型,分析在动态工况下内部各电池单体的容量及SOH退化情况,并给出该型电池组寿命的薄弱环节。结果动态工况下,锂电池退化轨迹呈高度非线性,环境温度为25~60℃时,随着温度的升高,电池组退化较快,但电池组内部最大温差反而减小。结论提出的方法能够很好地量化实际复杂动态工况对锂电池组退化的影响,为其可靠性设计和运行管理提供了技术支撑。The work aims to propose a simulation analysis method for capacity degradation under actual complex dynamic conditions to improve the accuracy of SOH evaluation of the lithium-ion battery pack.A multi-physical coupling simulation model of the lithium-ion battery pack was established by coupling the P2D electrochemical and thermal model of multiple bat-tery cells and the series parallel equivalent circuit,thermal and fluid dynamic model of the battery pack.A generalized dynamic load spectrum of the lithium-ion battery pack was constructed by analyzing the dynamic characteristics of current,temperature and other operating conditions in the actual use of the battery system.The model validation and the multi-physical simulation analysis of a typical 3 parallel-5 series lithium-ion battery pack were carried out.Then the capacity degradation model based on the SEI film formation mechanism was coupled to analyze the capacity and SoH degradation of each cell in the battery pack under dynamic conditions.The life weak links of the battery pack were obtained.The results showed that the degradation trajectory of the lithium-ion battery was highly nonlinear under dynamic conditions.The battery pack degraded rapidly with the increase of ambient temperature from 25℃to 60℃,but the maximum temperature difference inside the battery pack decreased.The proposed method can well quantify the impact of actual complex dynamic conditions on degradation of the lithium-ion battery pack,and provide technical support for its reliability design and operation management.

关 键 词：锂电池组 多物理场 动态工况 耦合仿真 SEI膜生成 容量退化 

分 类 号：N945.17[自然科学总论—系统科学]