基于电化学老化衰退模型的锂离子动力电池外特性

External characteristics of lithium-ion power battery based on electrochemical aging decay model

当前锂离子动力电池电化学模型存在模型复杂、建模难度大、计算效率低、老化评估效果差的问题,本文提出一种考虑电池衰退老化的机理模型(ADME).本文首先通过有限差分法对伪二维(P2D)电化学模型进行离散降阶处理,得到简化伪二维(SP2D)模型.在SP2D模型的基础上,基于阴阳两极发生的副反应导致的衰退老化现象,提出一种考虑电池衰退老化的机理模型.其次,使用多变量偏差补偿最小二乘法实现模型参数辨识.最后通过动力电池衰退老化性能循环实验,对比分析了恒流、脉冲工况下SP2D模型和ADME模型的终端电压输出.结果表明:ADME模型较为简单、计算效率和估算精度高,可以有效评估电池容量老化衰退,得到理想的锂离子动力电池外特性曲线.

The current electrochemical models of lithium-ion power batteries have many problems,such as complex models,difficult modeling,low computational efficiency and poor aging evaluation effect.In this paper,a mechanism model(ADME)considering battery decay and aging is proposed.In this paper,the pseudo-two-dimensions(P2D)electrochemical model is first reduced by finite difference method to obtain a simplified P2D(SP2D).On the basis of SP2D model,a mechanism model considering battery decay and aging is proposed,which is based on the degradation and aging phenomenon caused by the side reactions between positive and negative electrodes.Secondly,the multivariate deviation compensation least square method is used to identify the model parameters.Finally,the terminal voltage output of SP2D model is compared with that of ADME model and the outputs from the two models are also analyzed through the cycle experiment on power battery aging performance,constant current and pulse condition.The results show that the ADME model is relatively simple,has high computational efficiency and estimation accuracy,and can effectively evaluate the aging decline of battery capacity,and obtain the ideal external characteristic curve of lithium ion power battery.