After obtaining EIS results, I have used an equivalent electrical circuit to fit the spectrum. It is comprised of Rs (CPE II Rct and W). Charge transfer resistance and Warburg impedance elements are in parallel with a Constant Phase Element. Solution resistance is in series with this arrangement. Following are the units I have used. I am struck with the units of W. What should be the units for W?? Thank you.
Rs: Ω cm2
CPE: µΩ-1 cm-2 sn
Rct: Ω cm2
W: ....................................???????
n: Unitless
Goodness of Fit (Chi-squared): Unitless
I would think that the units for all elements must be same : Ohm
otherwise there is no dimensional coherence
Hello,
I agree with the units you mention, here the units I use:
- Rs and Rtc : Ω . cm-2
- CPE: Ω-1. cm-2 . sn
- W : Ω-1. cm-2 . s1/2
Warburg is just a CPE with a constant phase of 45°, so n =1/2.
Best Regards
- Badges
- Science topic