Battery aging is a natural process that contributes to capacity and power fade, resulting in a gradual performance degradation over time and usage. State-of-charge (SOC) and state-of-health (SOH) monitoring of an aging battery poses a challenging task to the battery management system (BMS) due to the lack of direct measurements. Estimation algorithms based on an electrochemical model that considers the impact of aging on physical battery parameters can provide accurate information on lithium concentration and cell capacity over a battery’s usable lifespan. A temperature-dependent electrochemical model, the enhanced single particle model (ESPM), forms the basis for the synthesis of an adaptive interconnected observer that exploits the relationship between capacity and power fade, due to the growth of solid electrolyte interphase layer (SEI), to enable combined estimation of states (lithium concentration in both electrodes and cell capacity) and aging-sensitive transport parameters (anode diffusion coefficient and SEI layer ionic conductivity). The practical stability conditions for the adaptive observer are derived using Lyapunov’s theory. Validation results against experimental data show a bounded capacity estimation error within 2% of its true value. Furthermore, the effectiveness of capacity estimation is tested for two cells at different stages of aging. Robustness of capacity estimates under measurement noise and sensor bias is studied.

中文翻译：

---

通过基于电化学模型的自适应互连观察器在线估计锂离子电池的容量

电池老化是一个自然过程，会导致容量和功率衰减，随着时间的推移和使用情况会导致性能逐渐下降。由于缺乏直接测量，老化电池的荷电状态 (SOC) 和健康状态 (SOH) 监测对电池管理系统 (BMS) 提出了具有挑战性的任务。基于电化学模型的估计算法考虑了老化对物理电池参数的影响，可以提供关于电池可用寿命内锂浓度和电池容量的准确信息。温度相关的电化学模型，即增强型单粒子模型 (ESPM)，构成了自适应互连观测器合成的基础，该观测器利用容量和功率衰减之间的关系，由于固体电解质界面层 (SEI) 的生长，能够对状态（两个电极中的锂浓度和电池容量）和老化敏感的传输参数（阳极扩散系数和 SEI 层离子电导率）进行组合估计。自适应观测器的实际稳定性条件是使用李雅普诺夫理论推导出来的。对实验数据的验证结果表明容量估计误差在其真实值的 2% 以内。此外，还针对处于不同老化阶段的两个电池单元测试了容量估计的有效性。研究了在测量噪声和传感器偏差下容量估计的稳健性。自适应观测器的实际稳定性条件是使用李雅普诺夫理论推导出来的。对实验数据的验证结果表明容量估计误差在其真实值的 2% 以内。此外，还针对处于不同老化阶段的两个电池单元测试了容量估计的有效性。研究了在测量噪声和传感器偏差下容量估计的稳健性。自适应观测器的实际稳定性条件是使用李雅普诺夫理论推导出来的。对实验数据的验证结果表明容量估计误差在其真实值的 2% 以内。此外，还针对处于不同老化阶段的两个电池单元测试了容量估计的有效性。研究了在测量噪声和传感器偏差下容量估计的稳健性。