As shown in this note, galvanostatic mode and potentiostatic mode are both usually valid for general EIS studies. We recommend galvanostatic control for EIS measurements on batteries with low internal resistances, and potentiostatic mode for high-impedance systems such as coatings or corrosion-resistant materials.

Source: https://www.gamry.com/application-notes/EIS/eis-potentiostatic-galvanostatic-mode/#:~:text=As%20shown%20in%20this%20note,coatings%20or%20corrosion%2Dresistant%20materials.

Thank you, Paul Akinyemi

Dear Kiran Donthula , some additional answers can be found in this article and the application notes that are referenced in the article. https://www.biologic.net/topics/peis-or-geis-that-is-the-question/

In summary, both techniques are equally accurate but GEIS (where the current is controlled) can be more suitable than PEIS in specific cases:

. if you are measuring low impedance systems (as said earlier)

. if you want to measure EIS while discharging a battery

. if you want to measure EIS on a corroding sample

The main drawback of GEIS is that it is not easy to know which amplitude is suitable, whereas in PEIS 5-10 mV is generally acceptable. This is why we offer the GEIS-AA technique, where you can set the amplitude in V while performing GEIS.

I hope this helps,

Best regards,

Nicolas