There is not enough information to give advice on interpretation. We need to know the electrochemical system your are investigating.. Also plots of your data (Nyquist or Bode) would be helpful.
Kind regards
Peter
Asking twice, answering twice...
Hi Vivek,
You've got more than 2 semi-circles there. Depending on the quality of the measurement (assuming that the data is real, stable and causal and the system you are using to measure is capable of making accurate measurements of these impedances) there are at least 4 processes/aspects that can be resolved there. I'm guessing what you would indicate as the first semi-circle is actually two that overlap a fair amount. The second has some lead in which may be something like a porous bound diffustion but could be...more complex. The third is the long tail which also looks like it may have two parts, but that could easily be due to something like drift or some other non-[linear, stable, causal] behavior.
But, so far as analysis, there still isn't enough information to go on here. Is this 2-electrode or 3-electrode? If the former you should run a 3 electrode measurement if possible. In either case the structure of the working electrode the nature of transport to the surface, whether there are other structures, or layers or membranes....for species to move through, would need to be known to start. Then to isolate between different processes you would need to run different experiments with variations in the components to see what is what.
On the other hand, if this is more QC then maybe you can get away with making a rough model that mostly fits the data, and then looking at "good" and "bad" cells to see if there is some way to distinguish?
In either case, you will likely run into a common issue with EIS analysis: the only person that can really tell you what is happening in your case is someone who has done the same research and figured it out already.
Thank you all for your opinions. Internet glitch that resulted twice posting, once there is a comment i can't delete the post.
Hi Prof. Jacob,
Even I was thinking that the semi circle consists overlapping regions. If that is the case, how would we deconvolute it?
Dear Vivek Tiwari,
show, 2 more, plots, apart the instant from the shown 20th cycle, as we can see on the title (of the shown plot). So, show, please, 2 more data plots (Nyquist and/or Bode), e.g. from the :
a) 1st cycle and another intermediate cycle,
b) say, near the 10th cycle.
Dear Satish,
You would use a fitting algorithm. EIS analysis software all makes use of this. To fit a region with two overlapping time constants (to simplify from above) you would construct or select an equivalent circuit with two time constants and then fit that to your data. It may also be possible to isolate the two time constants (e.g. going from 2 electrode to 3 electrode measurement) but since you can have multiple processes at a single electrode isolation is sometimes not possible. (Also, I'm not a professor--Dr. yes, but not a prof.)
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