In this publication we extend a state-of-the-art electrode open circuit potential model for blend electrodes and inhomogeneous lithiation. We introduce a bi-level optimization algorithm to estimate the open parameters of the electrode model using measurements conducted on the full-cell level with state-of-the-art testing equipment. As input for the optimization algorithm, we use data from a pseudo open-circuit voltage aging study to estimate the electrode potential curves, the electrode capacities, and the capacity of cyclable lithium over lifetime without opening the cell. We validate our method against measurements on commercial lithium-ion cells with the electrode materials LFP-C, NMC-SiC and NCA-SiC, and compare the estimated electrode pseudo open-circuit potential curves to measurements conducted on harvested half-cells. We conclude that the presented non-destructive method of half-cell open-circuit potential modeling offers an alternative to complex cell disassembly and electrode material harvesting for degradation mode analysis.

中文翻译：

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锂离子电池无损电极电位和开路电压老化评估

在本出版物中，我们扩展了用于混合电极和不均匀锂化的最先进的电极开路电位模型。我们引入了双层优化算法，使用最先进的测试设备在全电池水平上进行测量来估计电极模型的开放参数。作为优化算法的输入，我们使用伪开路电压老化研究的数据来估计电极电位曲线、电极容量以及可循环锂在整个生命周期内的容量，而无需打开电池。我们根据使用电极材料 LFP-C、NMC-SiC 和 NCA-SiC 的商用锂离子电池的测量来验证我们的方法，并将估计的电极伪开路电位曲线与对收获的半电池进行的测量进行比较。我们得出的结论是，所提出的半电池开路电位建模的非破坏性方法为复杂的电池拆卸和电极材料收集以进行降解模式分析提供了替代方案。