Hi,
I have performed CV measurement of an assambled EDLC by Gamry Interface 5000 Instrument. I used both "regular" and PWR cyclic voltammetry technique. I obtained different results. In the case of "regular" CV, the shape of voltammograms significantly differs from a typical rectangle at low voltage sweep rates. In comparsion, a box-type shape with an excellent charge propagation is observed in voltammograms from PWR CV (for the same capacitor device). Could someone please explain me how this happened?
The upper graph shows a typical response using a starircase, discrete step, approximation of a linear voltage sweep. This has to do with the time constant of the circuit; at lower scan rates, the current spike that results from the applied discrete step in the potential is discarded, since the current is sampled at the end of the step.
I assume that this PWR mode is trying to oversample the resulting transient, taking more intermediate readings and averaging them along the way.
Dear Tuomas,
I kindly thank you for the helpful reply.
Best regards,
Dawid