Dynamic electrochemical impedance spectroscopy reconstructed from continuous impedance measurement of single frequency during charging/discharging

In this study, a novel implementation of dynamic electrochemical impedance spectroscopy (DEIS) is proposed. The method first measures the impedance continuously at a single frequency during one charging/discharging cycle, then repeats the measurement at a number of other selected frequencies. The impedance spectrum at a specific SOC is obtained by interpolating and collecting the impedance at all of the selected frequencies. The charge transfer resistance, R-ct, from the DEIS is smaller than that from the steady EIS in a wide state-of-charge (SOC) range from 0.4 to 1.0, the R-ct during charging is generally smaller than that during discharging for the battery chemistry used in this study. (C) 2014 Published by Elsevier B.V.