# How do you calculate a charging current during a square wave potential pulse?

Details I have are the pulse length, pulse amplitude, electrode surface area, distance between electrodes.

Details I have are the pulse length, pulse amplitude, electrode surface area, distance between electrodes.

- Do you mean that charging current is a peak current response of voltammogram?
- No, I mean, if I were to apply a square potential pulse of say 5 V to a 1mm sq electrode for 10 ns how would I calculate the charging current, i.e. the current response for charging the surface rather than the faradaic current.
- I would suggest you to model an equivalent electrical circuit for the electrode-electrolyte interface for your system.

This can be done by using EIS techniques. I am sure you would be knowing such techniques.

Once you have modeled an equivalent electrical circuit, you can solve and do Feed-Response analysis as you require. Square wave will give the response similar to the fig. 1 in the attachment: "Figures.PNG".

As an example, the equation for the equivalent electrical circuit for the electrode-electrolyte interface can be of similar to the fig. 2 in the attachment: "Figures.PNG"

I hope this was useful!

Just to end, please compare the experimental and theoretical responses as they may not match sometimes because of errors in the modeling. - One thing to note here is the polarization should be of small signal around OCP! Large magnitude signals may give surprising results if above method is followed!

In such cases, mathematical equations as like Tafel's and similar others for Kinetics of electrode-electrolyte interface should be used to find current voltage relationships.

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