Dunn Method Clarification Step by Step

[@santoshsharma8989]

I was struggling for a clear instructions, and you just did. Thankyou. It was very helpful.

[@jabirshahbaz-v2l]

hi I am stuck at a point time 9:11 where we find the K value after finding the oxidation and reduction current .. scan rate square is fine but next two steps..?

[@ArunKumar-bm6he]

Thank you for sharing your knowledge. It was very helpful for me to calculate the contribution values. However i have a doubt in your video, where inthe Dunn real sheet you have took different voltage values. But at 0.4 V in the Dunn real sheet the oxidation and redution values are different, as you have fixed at 1 mv/s the vaules should be same as mentioned in the Dunns R2 and K value sheet. But the values are different in Dunn real sheet. Can you help to me clarify this one ? Thank you

[@ThuTran-cj3uh]

Thank you so much. Your video is really helpful. I completely understand the calculation

[@jumpingdude766]

Thank you very much for the clear explanation of how you made the plot of the capacitive contribution, you are the only video I have found that actually shows this. One question: Is there a reference from which you took this method? Or did you invent it yourself?

[@DrHaffeast]

The method is already well established. I just improvise a bit to make it easier to understand.

[@김밍밍-j4y]

Thank you for your useful and good educational materials. May I ask you a few questions? Q1. As far as I understand, even the same potential will show different capacitive and diffusion % in reduction and oxidation, but I wonder why the 12:05 Excel chart multiplied by the same ratio.. Q2. And when plotting a chart showing the capacitive and diffusion rate by scan rate in step 5 (11:47) as a bar, the value will vary for each potential. I wonder if you plot only the value based on a specific potential or average it by calculating the ratio at multiple points.

[@김밍밍-j4y]

I would appreciate it if you could give me an answer. And once again, thank you very much for the high quality lecture

[@DrHaffeast]

Hi. Thank you for your interest. Q1 The capacitive and diffusion contribution is determined by the K1 and K2 value. Yes. If you determine the value of K1 and K2 at different voltages, then the percentage of both contributions and diffusion will be different. That is why we declare at what potential we run the analysis. In short, that is why I multiply the contribution of CV at different scan rates using the same K1 and K2 value. Q2. I used specific the potential, which is the same potential used to determine K1 and K2 value.

[@anjumhussain6316]

Respected Sir! A.O.A, hope you are fine and doing well. Thank you very much for your video. Kindly clarify about the stacking area of curves (16:23).

[@DrHaffeast]

The stacking area is based on the CV of 2 different contribution diffusion (Pseudo/battery type) and diffusion limiting (EDLC).

[@muhammadazim8046]

Thank you for this easy step be step guide. please let me know where i can find the further literature and detailed version from book as i constantly looking for that

[@shamsaabdulshukkur9225]

I appreciate your effort. This video was really helpful!!Please do more video

[@ahm460]

You are doing great job, mashaAllah. Please just take one curve at specific scan rate and complete the whole calculation process. If possible for you

[@DrHaffeast]

Later I will make video regarding your question.

[@shoeb321]

Thank you very much for your video. It is extremely helpful for understanding Dunn's analysis. If you could kindly share your Origin and Excel sheets, it would be immensely helpful for us. Thank you once again for your assistance.

[@DrHaffeast]

If I share the Origin and Excel sheet, then you will not learn. Try give some effort by plotting yourselves. Thank you.

[@komalrao4919]

Plz clarify whic option is used for plot at the end of dunn plot ....how we find inner curve filled

[@sairasarwar7959]

We get k1 and k2 values seperaterly for anode ic and cathodoc current. So which one have you used for contribution %??oxidation or reduction?

[@DrHaffeast]

based on anode or oxidation.

[@shamsaabdulshukkur9225]

Please make a video how to calculate retention rate

[@thbajantri2397]

Thank you sir.very informative and helpful video

[@rajabhussain5061]

AOA... Sir pl guide me which type of Ag/AgCl electrode is best? Also other necessary items for the supercapacitor testing like electrodes, connections, connecting wires, electrode assembly?

[@DrHaffeast]

normally we bought reference from BASi. Wire and connector all supplied by the potenstiostat. It can be Autolab, Versastat, Gamry, CHI or etc

[@gurunathank5743]

If I calculate K value based on cathodic current the slope values becomes negative, does it can be taken as positive or k value has to be found only using anodic current?

[@DrHaffeast]

Most of the case I used the anodic current. Try repeat the calculation using anodic current.

[@rajabhussain5061]

respected HAtts off. here is one question to you. if we have b=0.56 and in contribution we get capacitive controlled means 60 cap, 40 diff @20mvs. is this ok for the pseudocapacitive device?here i have used Reduction current? ongoing diffusion contribution is decreased.

[@DrHaffeast]

@@rajabhussain5061 at high scan rate like 20mV/s you will likely to observe high capacitive contribution instead of diffusion. Further increasing the scan rate the diffusion normally will reduce because electrolyte ion is only capable of fully utilising the surface of electrode materials instead of bulk material. In my opinion it is okay for your pseudocapacitive device.

[@rajabhussain5061]

@@DrHaffeast Thank you so dear.. I really appreciate your prompt response.

[@jabirshahbaz-v2l]

Hi How can I draw a CV graph between Potential and Current density (mA/cm^2) ? I have a current in (A) and my CV shows EDL behavior.

[@DrHaffeast]

Area divided by mass loading of your active material.

[@jabirshahbaz-v2l]

@@DrHaffeast my active material is 2mg and Area is 2.4^-3.. please briefly explain

[@SwathyN-fr9ch]

Hello, at different scan rates, you should get different contributions from capacitive and diffusion but you are putting the same contribution for all the rates. How is it possible? Can you explain?

[@DrHaffeast]

The K value is the same. contribution is different. K1V and K2Vpower1/2. V is scan rate. how come the contribution is the same if V is changing.

[@SmSuraj31]

Hello Sir Thank you for this great video I have concern regarding k value calculation.... Is the V in volt or Mili volt? And same for the current ampere or milliampere?

[@SmSuraj31]

If I have changed a unit.. the k value also changes and affect the charge contribution ratio

[@DrHaffeast]

If you are using V, you must also use A.

[@DrHaffeast]

Yes. Thats why you meed to fix the either to use A/V or mA/mV in your calculation.

[@SmSuraj31]

Thank you

[@sadafsiddique2048]

Aoa! I appreciate your efforts, 3rd video on same method. thanks for sharing the knowledge however, a little confusion i encountered while doing my calculation. if you can answer, if my intercept value comes negative, it means diffusion contribution current (K2V^(0.5)) is negative and while adding both contributions (i capacitive +(-i diffusive) should i subtract it according to substraction maths rule or ignoring the negative I should add both contributions instead of substracting??

[@DrHaffeast]

Yeah Sometimes I also encountered that problem. I think we should ignore the negative. If you consider the negative then capacitive and diffusion contribution will not equal to 100%. This is my honest opinion you should consult other experts to get more accurate answers.

[@sadafsiddique2048]

@@DrHaffeast Sure! thanks for your kind reply.

[@osamazahid8861]

​@sadafsiddique2048 i have the same issue. Can you find out suitable answar or suitable method to find capacitive and diffusive with -ve sign?

[@osamazahid8861]

During calculation of b value is it necessary that we took only peak current or we can fix any point in oxidation curve?

[@DrHaffeast]

any point also can

[@rutuparnasamal8630]

Thank you very much sir for sharing knowledge with us.

[@DrHaffeast]

Thanks and welcome.

[@sairasarwar7959]

how do find R-value? what is the formula or fit to get it? you just show the Excel sheet for R value please show the calculations too.

[@DrHaffeast]

You can use origin linear fit to get the R-value

[@sairasarwar7959]

Thanks but please make a video to show how to plot bar chat for percentage capacitive and diffusive contribution​@@DrHaffeast

[@sakaraymadhuri9302]

Hello Sir, In step 8 after plotting log scan rate vs log current, after linear fitting which value did you take as b value, Could you please clarify

[@DrHaffeast]

b value is the value of slope. Plot log current vs log scan rate. Then obtained the b-value.

[@sakaraymadhuri9302]

Thank you sir@@DrHaffeast

[@arvindkumarmishra6993]

Sir, kindly tell me i how plot in origin , because as per ur work we have 4 y' and 1 x axis ,but when we plot i got cv curve but four different line in cv,i didn't fill the area , where i did wrong kindly help

[@NgutorAkiiga-ry1cv]

Thank you for the video. Please can you send me a rough sheet on how to plot & calculate the percentage retention & limit of detection in a CV/Amperometry measurements?

[@DrHaffeast]

Sorry I don't give fish. I just help you fishing.

[@NgutorAkiiga-ry1cv]

Okay. It's fine, thank you

[@asifamumtaz2723]

It is very helpful video but i have tried my best but couldnt get what is R after (current responce after reduction) i mean how did u calculate it. Kindly clarify

[@DrHaffeast]

Later I will make video regarding your question.

[@safaak4884]

Thank you doctor, I have totally understand the issue :)

[@lintree1061]

Thank you for your video. Previously, I watched different videos to find the b value, they used log (ipa) and log (scan rate) and the way they estimated "ipa" = i(peak)-i(base line) is different with you.They doesn't fix the potential value. So I'm a bit confused that their method is corrent or not?

[@DrHaffeast]

For obtaining the current response, this method is correct. Normally they use this method in sensor. If your CV has distinct redox peak, then this method can be used. However, in determining the capacitive and diffusion contribution, we often need to fix the potential. This is because by increasing the scan rates the maximum redox peaks tend to be shifted to right. Thus, it is more practical to fix the voltage value. However if your graph have no shifting then you can use ipa method.

[@NgutorAkiiga-ry1cv]

Hello, sir. I need to know more about the ipa method. I am working on a biosensor & I wish to know what method to follow to get my sensitivity and Limit of detection

[@lintree1061]

@@DrHaffeast Thank you very much for your response.

[@തൂലികപ്രണയം]

Thank you sir for this video.

[@DrHaffeast]

Welcome

[@SahebBag-t6y]

Nice video sir.

[@attiyanawaz5621]

A.O.A sir how you are finding different values of k1 and k2

[@attiyanawaz5621]

And in graph for finding values of k1 and k2 which parameters you are plotting on x axis and y axis

[@DrHaffeast]

Based on y intercept and gradient.

[@DrHaffeast]

@@attiyanawaz5621 kzbin.info/www/bejne/rKPEZHuAp6ymeNE for details and for your reference.

[@attiyanawaz5621]

Thanks sir

[@R0SE2628]

Thank you Thank you Thank you Thank you Thank you ♾️

[@DrHaffeast]

You are welcome 🙂.