Galvanostatic EIS Purpose
The Electrochemical Energy Galvanostatic EIS technique is used to characterize the electrochemical interfaces within an energy device or cell. It is especially useful when the potential of the interface is changing with time. A small-signal AC-current excitation is applied to an electrochemical cell. The phase-sensitive AC voltage response of the interface is measured while the frequency of the excitation signal is varied.
Galvanostatic EIS can be useful in many areas of electrochemistry, including research in batteries, fuel cells, supercapacitors, electrode kinetics, and industrial electrolysis. It can be used to measure the EIS spectrum of a battery while the battery is being discharged or cycled.
The output of an EIS experiment is a complex impedance spectrum. The term complex is used in its mathematical sense: containing both real and imaginary terms. An EIS spectrum is usually graphed as either a Bode plot (impedance magnitude and phase plotted versus frequency) or a Nyquist plot (imaginary impedance plotted versus real impedance). Analysis of the impedance spectrum can give you the following information:
- Polarization resistance
- Double-layer capacitance
- Solution resistance
- Mechanistic and kinetic information
This is a half-cell, full-cell, stack, or dual-electrometer experiment. Dual-electrometer mode is only available with the Interface 5000.
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