On-Load Impedance Measurements on Automotive Lithium-Ionn Cells

The contribution presents examples for electrochemical impedance spectroscopy data taken on automotive lithium-ion battery cells. Discharge was done with the help of an external load. The measurements were done with an initial state of charge of about 97 %, at 23 degrees C and from 5000-0.1 Hz. Spectra were fitted with an equivalent circuit containing two RC elements and an inductance. For load currents up to 20 A and in certain regions of the used frequency range, it is possible to measure impedance spectra also under load that almost coincide with load-free spectra.

Automated summary

This study presents examples of electrochemical impedance spectroscopy data taken on automotive lithium-ion battery cells, showing that impedance spectra can be measured under load almost coinciding with load-free spectra under certain conditions.