Determination of suitable parameters for battery analysis by Electrochemical Impedance Spectroscopy

Abstract

Electrochemical Impedance Spectroscopy (EIS) is one of the most powerful tools for the study of batteries. The applied AC current, range of frequency sweep, points per decade represented, length of the pause time after a change in the state of charge (SOC) and length of the pause time after a change in the ambient temperature must have suitable values to obtain useful results from EIS tests. A method to determine and optimize these parameters is presented in this paper. It is based on the limits imposed by the battery, the tests carried out, the instruments employed and the use of Kramers-Kronig relations. The method has been checked using two kinds of lithium batteries: a lithium iron phosphate (LFP) battery and a lithium cobalt oxide (LCO) battery.

Operational Strategies to Improve the Performance and Long‐Term Cyclability of Intermediate Temperature Sodium‐Sulfur Batteries

“…The electrochemical impedance spectrum (EIS) was recorded after every 5 th charge and discharge, with 5 min of rest before and after the EIS measurements. To avoid drift in the cell potential, EIS spectra were recorded at a constant current mode between 250 kHz–0.1 Hz [65,66] . The applied constant current was 10 % of its respective galvanostatic charge‐discharge current.…”

“…To avoid drift in the cell potential, EIS spectra were recorded at a constant current mode between 250 kHz-0.1 Hz. [65,66] The applied constant current was 10 % of its respective galvanostatic charge-discharge current. In the case of the conductance cell, EIS spectrums were recorded at constant potential mode by applying a small sinusoidal voltage (10 mV) at frequencies between 250 kHz and 1 Hz.…”

Electrochemical Impedance and its Applications in Energy‐Storage Systems

“…The validation test needs to verify if the four conditions are satisfied within the whole frequency range, and to identify the noncompliant data points in the impedance spectrum so they can be removed from the spectrum used for subsequent analysis. Figure shows an example of the residual of different impedance spectra taken from the same battery . Figure A corresponds to the impedance test with large error, while Figure B corresponds to the one with small error and is K–K compliant.…”

State-of-Charge Monitoring by Impedance Spectroscopy during Long-Term Self-Discharge of Supercapacitors and Lithium-Ion Batteries

“…Earlier approaches [30,31] concentrated on the cell resistance. The internal resistance R of a lithium-ion battery was reported to reach an unclear minimum around SoC ≈ 50%.…”