外在多因素作用下锂离子电池性能衰减机理及寿命预测研究

With the rapid popularization of electric vehicles, the performance attenuation and life prediction of lithium-ion traction battery are becoming a problem urgently needs to be solved. This project is about to carry on the fundamental research that includes external multi-factors’ quantitative effects on lithium-ion batteries’ performance attenuation, simplification methods of fading mechanism model with external multi-factors’ coupling effects, the extraction of lithium-ion battery performance attenuation’s trajectory characteristic parameters and simulation method. First, We’ll analyze the impact of multi-factors on the lithium-ion battery’s performance attenuation, uncover the attenuation mechanism of multi-factors on the battery performance attenuation, get the quantitative relationship of the external multi-factors’ coupling characteristics on battery performance attenuation. Second, we’ll explore the identification method of battery performance attenuation, establish the side reaction model with external multi-factors’ effects, put forward model simplification methods with multi-stress conditions, build the linear parameter varying battery performance attenuation model. Third, we’ll mine performance characteristic parameters of lithium-ion battery’s attenuation trajectory with multi-factors’ effects, put forward the battery performance attenuation trend simulation method of multi-stress conditions, build battery life prediction method based on the battery with multi-factors’ effects. This project will provide theory support to lithium-ion battery’s performance attenuation, life prediction and usefulness.

随着电动汽车的迅速推广，锂离子动力电池的性能衰减和寿命估计成为急需解决的难题。本项目针对外在多因素对锂离子电池性能衰减的定量作用、锂离子电池衰减机理模型在外在多因素耦合作用下的降阶简化方法、锂离子电池性能衰减轨迹特征参数提取与模拟方法等内容开展基础研究。解析外在多因素对锂离子电池性能衰减的影响，揭示外在多因素对电池性能衰减的作用机理，得到外在多因素对电池性能衰减耦合特性的定量关系；探究电池性能衰减的辨识方法，建立外在多因素作用的电池电化学副反应模型，提出综合多应力条件的模型简化方法，构建线性变参数结构的电池性能衰减模型；挖掘外在多因素作用的锂离子电池性能衰减轨迹特征参数，提出多应力条件的电池性能衰减趋势模拟方法，构建电池外在多因素作用的电池寿命预测方法；本项目将为锂离子电池性能衰减、寿命预测以及电池的使用提供系统的理论支撑。

课题深入研究电池性能衰减机理、锂离子电池衰减机理模型降阶简化方法以及征参数提取与模拟方法。通过设计老化试验，定量分析老化状态对动力电池基本性能影响，包括动力电池老化对电池开路电压特性、直流内阻特性、电池极化时间的影响；通过容量增量法研究电池的老化机理，分析电池性能衰减的外在因素对内在原因的影响机理；采用comsol软件搭建了锂离子电池的老化机理模型，分别对电池在不同测试工况和不同温度下进行了仿真分析；基于迭代辨识技术研究锂离子电池SOH在线估算方法，采用UDDS城市实时行驶工况测试数据考察算法验证了算法的精度和鲁棒性。