I am studying the need of Electrochemical Impedance spectroscopy in Lithium ion battery testing for Electic vehicles.
I understand each AC potential signal with a fixed frequency will create a AC current response in time domain and then can be studied in frequency domain. Can anyone explain a bit on the role of AC frequency in the frequency analysis of the response current in Frequency domain??
Dear Deepak Raut,
an initial AC test is applied at a single frequency (typically at f1=1kHz). The Z(f) is measured over a preset-range of frequencies (typ. range : 10mHz - 100kHz, for a Lithium ion battery).
Some introd. Refs on Electrochemical Impedance Spectroscopy (EIS):
https://www.jlab.org/conferences/tfsrf/Thursday/Th2_1-EIS%20intro%20Reece.pdf
http://pirg.ch.pw.edu.pl/instrukcje/eis_extensive_introduction.pdf
http://zahner.de/pdf/EIS.pdf, https://www.gamry.com/assets/Uploads/Basics-of-Electrochemical-Impedance-Spectroscopy.pdf
https://itunes.apple.com/us/book/electrochemical-impedance/id473539902?mt=11
Dear Deepak Raut,
an initial AC test is applied at a single frequency (typically at f1=1kHz). The Z(f) is measured over a preset-range of frequencies (typ. range : 10mHz - 100kHz, for a Lithium ion battery).
Some introd. Refs on Electrochemical Impedance Spectroscopy (EIS):
https://www.jlab.org/conferences/tfsrf/Thursday/Th2_1-EIS%20intro%20Reece.pdf
http://pirg.ch.pw.edu.pl/instrukcje/eis_extensive_introduction.pdf
http://zahner.de/pdf/EIS.pdf, https://www.gamry.com/assets/Uploads/Basics-of-Electrochemical-Impedance-Spectroscopy.pdf
https://itunes.apple.com/us/book/electrochemical-impedance/id473539902?mt=11
Addding to Ioannis,
impedance spectroscopy is a plot of the impedance of a device with frequency. The impedance is a complex quantity having magnitude and phase or real and imaginary part. In case of the Battery one measure the small signal inexpedience of a battery by operating the battery at a specific voltage and current , say during the discharging.
The impedance is measured by applying ab AC voltage with specific frequency from a sinewave generator, and measure the AC current . Then calculates the magnitude of the impedance by dividing Vp/Ip the pea voltage over the pea current. The phase difference between the the sinewaves of the voltage and current is phase of the impedance. In case of batteries the the reactive part is negligible compared to the resistive part and the phase of the impedance is more or less equal to zero.
If you use single frequency sine wave you will have only one impedance point at the specified frequency. However one can apply multiple tones simultaneously having frequencies covering the hole spectrum range. In this case the the response current will be also of multitone and one can analyse this current in the frequency domain by using the discrete fourier transform or fast fourier transform.It is a signal converter from the time domain to frequency domain where one analyse the signal into its frequency components in the frequency domain where one obtains the amplitudes of the all frequency component in the signal.
wish you success
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