Experimental analysis of the effects of aging on impedance dependencies

Impedance-based methods for battery diagnostics are becoming increasingly important as lithium-ion batteries continue to proliferate in mobility applications. While electrochemical impedance spectroscopy (EIS) offers powerful diagnostic capabilities, its practical implementation in battery management systems faces challenges due to complex inter-dependencies between temperature , State of Charge , DC-current offset , and State of Health . This study presents a comprehensive analysis of these dependencies through systematic EIS measurements across different aging stages of lithium-ion batteries subjected to combined cycling and fast-charging protocols. The research employs a three-pronged approach: conducting realistic aging series using standard cycles and fast charging, performing systematic characterization of complex impedance at discrete aging stages, and identifying individual parameter sensitivities through global sensitivity analysis. Our methodology aims to identify optimal frequency ranges for impedance-based state estimation and provide a framework for adaptive parameter tuning in practical applications. The results reveal distinct frequency-dependent behaviors and sensitivity patterns that can improve the development of more robust battery management systems, particularly for applications requiring accurate state estimation during fast charging operations. • Realistic aging series using a combination of standard cycles and fast charging method. • Systematic characterization of complex impedance spectra over battery aging. • Identification and quantification of individual sensitivities of the investigated parameters.