Electrochemical impedance spectroscopy of Li-ion cells

Impedance measurements of li-ion accumulators and supercapacitors are performed to define the most sensitive ones to the state of charge parameters of a chemical power source. The measurements are conducted by potentiostat-galvanostat PARSTAT 4000 in the frequency range 0.1 to 2000 Hz for different states. An increase in impedance with a decrease in the state of charge of the studied elements is observed for all studied power sources. Equivalent circuit parameters are calculated for the sinusoidal current signal response of the power source. The results obtained can be used for diagnostics of chemical power sources.