锂离子电池材料准静态压缩本构模型  

Quasi-static constitutive modeling of lithium-ion battery materials under compression

作　　者：邱宇超 陈佰爽 陈诚 钱瑞鹏 QIU Yuchao;CHEN Baishuang;CHEN Cheng;QIAN Ruipeng(Pylon Technologies,Co.,Ltd.,Shanghai 200120,China;State Key Laboratory of Hydroscience and Engineering-Tsinghua University,Beijing 100084,China)

机构地区：[1]上海派能能源科技股份有限公司,上海200120 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《储能科学与技术》2024年第10期3518-3522,共5页Energy Storage Science and Technology

基　　金：国家自然科学基金青年基金项目(52304094);国家重点研发计划课题(2023YFB4005505)。

摘　　要：锂离子电池储能系统在长循环过程中,电芯受力波动上升,这会影响电芯寿命及系统可靠性。数值模拟方法是预测电芯受力状态的有效方法,建立符合电芯力学特性的本构模型,并应用于数值模拟模型当中,可较准确地预测电芯受力状态,为工程设计提供参考。通过对电芯进行单轴压缩试验测试发现,电芯在加载过程中,表现有明显的非线性塑性行为;在卸载过程中,又表现有明显的非线性弹性行为,无法使用单一本构模型,对其加卸载力学响应行为进行表征。本工作使用两种类型的本构模型对电芯进行耦合建模,采用PE(porous elasticity)本构模型表征电芯的非线性弹性行为,采用CFP(crushable foam plasticity)本构模型表征电芯的非线性塑性及应变硬化行为。使用上述两种本构模型,对测试应力-应变数据进行材料参数反演,并将电芯视为层叠复合材料,分层交替赋予上述本构模型及材料参数,对电芯数值建模。针对电芯的单轴压缩试验测试工况,建立了仿真模型并数值求解,对比数值模拟结果与实际测试结果的应力-应变曲线数据,结果证明该建模方法可较准确表征电芯在加卸载过程中的力学行为,且吻合程度可满足工程仿真应用需求。In the lithium-ion battery energy storage systems,the cell experiences increased force fluctuations over prolonged cycles,which can impact cell lifespan and system reliability.Numerical simulation is an effective tool for predicting the stress state of the cell.By developing a constitutive model that accurately reflects the mechanical properties of the cell and applying it to numerical simulations,we can precisely predict the cell's stress state and provide valuable insights for engineering design.Uniaxial compression tests of the battery reveal distinct nonlinear plastic behavior during loading and nonlinear elastic behavior during unloading.This indicates that a single constitutive model is insufficient to accurately characterize the mechanical response of the cell during both loading and unloading processes.This paper employs two types of constitutive models to accurately represent the cell's behavior,the PE(porous elasticity)model for nonlinear elastic behavior and the CFP(crushable foam plasticity)model for nonlinear plasticity and strain hardening.By using these models,the material parameters from the stress-strain curve obtained from testing are inversed.The core of the cell is treated as a laminated composite,and the PE and CFP models,along with their respective material parameters,are alternately applied to develop the numerical model of the cell.A simulation model is established and numerically solved to match the conditions of the uniaxial compression test of the battery.The stress-strain curve data from the numerical simulation results are compared with the actual test results.The findings indicate that the modeling method accurately characterizes the mechanical behavior of the cell during both loading and unloading processes,with a degree of agreement that meets the requirements for engineering simulation applications.

关 键 词：锂离子电池 本构模型 数值模拟 单轴压缩 膨胀力 

分 类 号：TM912[电气工程—电力电子与电力传动]