Hello Takwa Chouki

As you are working in solution, you should be able to access the resistance of the solution (real part of the impedance in the high frequencies).

You should find this link interesting:

https://www.gamry.com/application-notes/instrumentation/understanding-ir-compensation/

This method uses a simplified form of EIS and assumes that the cell impedance at high frequencies is identical to Ru.

Best regards,

Marie B.

yes, you can do it manually. actually sometimes, that is more convincing than the automatically calibration.

Hello,

Of course, you can use the electrolyte resistance Rs measured by EIS to compensate the ohmic drop. What you have to do is to measure Rs by EIS, make your LSV and afterward you correct your plot with E-Rs x i.

Best Regards

Thomas

Hello,

The electrolyte resistance Rs measured by EIS can only be used to compensate the ohmic drop for hydrodynamic/steady-state LSV, on a RDE for example, not for classical LSV in unstirred electrolyte.

Have a look at

https://www.bio-logic.net/wp-content/uploads/20131128-Application_note_41-2.pdf

or

https://demonstrations.wolfram.com/CyclicVoltammetryCorruptedByOhmicDrop/

Regards.

jpd

Hello,

you can make a manual IR corrections, that is just shifting the potential afterwards, for steady-state or close to steady-states experiments. Examples are staircase voltammetry, very slow LSV or CV, and galvanostatic experiments.

The problem is connected with the fact that the presence of the uncompensated resistance not only changes the real interfacial potential but also the rate at which it changes compared to the applied bias. This affect the mass transport, so if your voltammetry shows a diffusion peak you cannot use this simple correction.

There are ways to drastically reduce the uncompensated resistance by changing the cell arrangement.

Thank you all for your answers.

Read module 2

IR-compensation during a measurement is always better than mathematical IR-correction after the measurement. But a IR-correction is always better than nothing.

Here are some issues you should be aware of.

The measured current is the sum of capacitive currents, current from surface reaction and faradaic current. All currents are depending on the potential, but in addition, the two first currents scales with the scan rate(v).

As you are using voltage sweeping techniques, due to the IR-drop, the real potential and scan rate at the interface are affected. In fact, the real applied scan rates can vary quite a lot. Post IR correction often disregards the effects of the scan rates. As an effect, the current peaks in a CV would never as high enough.

So, based on this, you can never make a perfect post measurement correction, which would be as good as making a IR-compensation

Gustav Karl Henrik Wiberg Thanks a lot.

Agreed with the answer above. This paper explains the iR drop, best practices and common mistakes are highlighted and practical examples are given . Enjoy ;)