Electrochemical Impedance Spectroscopy Measurement of Lithium-Ion Batteries Based on a Dual-Domain Multi-Frequency Excitation

Résumé fourni par la source

With the rapid proliferation of electric vehicles, battery-related safety accidents have become increasingly frequent, which highlights the growing importance of state estimation and health diagnosis. Electrochemical Impedance Spectroscopy (EIS) is an effective approach for analyzing internal battery states, owing to its strong mechanism-oriented diagnostic capability. However, conventional EIS measurement relies on expensive electrochemical workstations and suffers from long testing time in the low-frequency region, making it difficult to meet the requirements of rapid measurement and online deployment. To address this issue, this paper proposes a dual-domain multi-frequency excitation scheme. Multi-sine excitation is introduced in the low-frequency region to improve the signal-to-noise ratio, while BMFS is adopted in the mid-tohigh frequency region to guarantee sufficient excitation energy density. In this way, the proposed method significantly enhances the low-frequency accuracy while preserving the fast multifrequency measurement capability. Experimental validation is conducted on both LCO and NMC cells. The results show that, compared with conventional EIS, the proposed method achieves only 0.82% magnitude error and 0.65° phase error, and enables wide-band high-accuracy impedance characterization under a single short excitation. This work provides a new pathway for low-cost, rapid, and highly generalizable EIS measurement, and offers potential engineering value for online battery health monitoring and deployment on the application side.

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