Development of future battery generations and quality control of current lithium-ion battery (LIB) systems require reliable techniques for the characterization of the complex dynamic processes in batteries. Electrochemical impedance spectroscopy (EIS) is an established tool for the electrochemical characterization of LIBs and the related ageing processes. Nevertheless, ensuring a reliable interpretation and validation of the impedance data remains challenging. Here we show how EIS complemented by microscopy data can be successfully used to follow battery ageing. We connect data from both methods in an electrochemical finite element model (FEM) to extract changes of intrinsic battery parameters, such as double layer capacitance, film resistance, exchange current density, and particle radii. Ageing mechanisms induced by cycling and temperature are investigated by EIS on commercial cells. Postmortem analysis of the anode and cathode electrodes is carried out to determine their initial micrometric and nanometric structure and to independently investigate morphological and electrical changes induced by ageing. While the obtained initial structural dimensions reduce drastically the number of adjustable parameters in the FEM model, which enables us to follow battery ageing processes noninvasively through the EIS spectra, the microscopy results of the aged cells prove independently the validity of the here presented approach.

未来电池世代的发展和当前锂离子电池 (LIB) 系统的质量控制需要可靠的技术来表征电池中的复杂动态过程。电化学阻抗谱 (EIS) 是用于 LIB 电化学表征和相关老化过程的成熟工具。然而，确保阻抗数据的可靠解释和验证仍然具有挑战性。在这里，我们展示了 EIS 辅以显微镜数据如何成功地用于跟踪电池老化。我们在电化学有限元模型 (FEM) 中连接两种方法的数据，以提取电池固有参数的变化，例如双层电容、薄膜电阻、交换电流密度和粒子半径。通过 EIS 在商业电池上研究由循环和温度引起的老化机制。对阳极和阴极电极进行死后分析，以确定它们的初始微米和纳米结构，并独立研究老化引起的形态和电学变化。虽然获得的初始结构尺寸大大减少了 FEM 模型中可调参数的数量，这使我们能够通过 EIS 光谱无创地跟踪电池老化过程，但老化电池的显微镜结果独立地证明了此处提出的方法的有效性。对阳极和阴极电极进行死后分析，以确定它们的初始微米和纳米结构，并独立研究老化引起的形态和电学变化。虽然获得的初始结构尺寸大大减少了 FEM 模型中可调参数的数量，这使我们能够通过 EIS 光谱无创地跟踪电池老化过程，但老化电池的显微镜结果独立地证明了此处提出的方法的有效性。对阳极和阴极电极进行死后分析，以确定它们的初始微米和纳米结构，并独立研究老化引起的形态和电学变化。虽然获得的初始结构尺寸大大减少了 FEM 模型中可调参数的数量，这使我们能够通过 EIS 光谱无创地跟踪电池老化过程，但老化电池的显微镜结果独立地证明了此处提出的方法的有效性。