Calculation of Specific capacitance | Cyclic Voltammetry Part-2 |

[@amr_elgendy4018]

Hi, could you please let me know when we must divide by 2 is it in the three electrodes cell or in the two-electrodes cell? what is the situation in case of the symmetric device and asymmetric device?

[@sharafpc786]

yes please explain

[@yhana8836]

Hi there. If I am not mistaken, there is no 2 at your previous derivation. Could you please verify this one how we ended up having 2 on the equation. Thank you

[@PHYSICSINSIGHT]

Ohh sorry... Its my bad... Actually the cv data is taken for 3 electrode system and capacitance is calculated for two electrode system and in 2 electrode system current is half of that in 3 electrode system, so taking this into consideration this half factor came in the capacitance expression. Hope you got it. So both expression are correct.

[@mohammedftouni6209]

@@PHYSICSINSIGHT it's just because you calculated the area between charge and discharge curves instead of the area between one of them with the x-axis. That's why you had to divide by 2.

[@salmaakhtarakhanam3519]

Sir.. could you please make a video on how to calculate Cdl value and ECSA value from CV plot.

[@federicadeluca8502]

Formula in part 1 is Cp=A/(mkΔV), why now is Cp=A/(2mkΔV), what is change? Thanks!

[@shoeb321]

Please help me regarding trasatti b value and deconvolution of CV and how to plot the diffusion area plot of cyclic voltammetry. Thank You

[@dr.ashishgupta4240]

can we use the integral option in origin to calculate the area?

[@saranyasankar6399]

Yes, we can

[@randomthoughts8782]

ur video is nice but i am facing problem that current at y=axis is in 10exp-7 range and mostly in vidos and reported data it is in 10exp-4 range as is in ur case, m i doing mistake in some conversion or what? please guide

[@suhagmittal762]

Very easy to unterstand... Thanks

[@tisascience388]

also i'm working on calculating electrochemical active surface area. its = Cdl/Cs i believe you are aware that the slope of I vs scan rate in the non-faradaic region of CV gives Cdl while for Cs i can follow your tutorial but does Cs in the formula means finding specific capacitance at different scan rates and averaging it. or just one Cs is sufficient? Kindly reply @physics insight and i also welcome other viewers/aspirants watching this video to kindly join the forum for discussion in clearing my doubt thanks in advance

[@AsimKhan-gn2dt]

I think first convert current into current density then measure the area??

[@tisascience388]

as you mentioned active mass = 1mg. does active mass is the amount of material that we coat over the electrode say, glassy carbon electrode.

[@PHYSICSINSIGHT]

Mass of coated material that is inside the solvent

[@tisascience388]

@@PHYSICSINSIGHT okay thanks

[@mitali-445]

Nice 👍👏

[@mdsaifurrahman5376]

Thanks for your nice tutorial. Is it possible to replace the active mass with an exposed area of the working electrode (WE)? Because I can't measure the mass of the deposited polymer on the WE. For example, I have made a WE and taken a picture of the exposed area before starting the cyclic voltammetry measurement. Later, I have measured the area of that exposed area by using ImageJ. Finally, I would like to use that area from the ImageJ analysis in the same equation that you showed just replacing the mass with the exposed area of the WE. In this case, the final result will appear as F/cm2. What do you think is it possible?

[@PHYSICSINSIGHT]

I think it will not be a good way to show your result... Because with exposed area you can't say how much amount of sample is active afterall it is the amount which is storing energy... So it is better to show your result in F/gm. Can you calculate the width of sample deposited on WE?

[@mdsaifurrahman5376]

@@PHYSICSINSIGHT yes we can measure the thickness of sample on WE by surface profiler

[@PHYSICSINSIGHT]

Ok then... Then you can find the volume of sample on electrode... Then multiply with concentration of polymer you will get the active mass... Do you know concentration of polymer?

[@mdsaifurrahman5376]

@@PHYSICSINSIGHT Yes, I know the concentration of the polymer solution that I used to make a free-standing electrode

[@ZeMakerpen]

Hi there, I was wondering how do I calculate the area without using origin? I want to use trapezoid method and from what I understood it's A = ((v2-v1)*(i1+i2))/2 could you verify that?

[@PHYSICSINSIGHT]

Why do you want to that? Any specific reason? And if you want to use trapezoid method then you cant just take a big trapezoid... You have to take small small trapezoid and have to add their area to get overall area(based on numerical method) which i dont suggest for this. And sorry for the late reply

[@PHYSICSINSIGHT]

Answered you to your previous comment

[@rameshkumar-cs4dn]

Good

[@Samouraimoh]

your calculation does not add up. Explain the conversion units used for each parameter to obtain 138.33 F/g.

[@p.asisters5446]

Thanks

[@rabbiashafique4504]

How u get answer as 138.33 g as when I am doing I get answer 0.13833 plz clarify

[@PHYSICSINSIGHT]

Are you sure about units? May be unit are not same... Do unit conversion

[@rabbiashafique4504]

@@PHYSICSINSIGHT how plz help.I am unable to do it plz help plz

[@rabbiashafique4504]

@@PHYSICSINSIGHT can u share screenshot of calculation of same measurement?plz

[@almanaratan]

@@rabbiashafique4504 well convert millivolt in scanrate to volts and milligram to grams in active mass

[@kavin884]

Thankyou sir

[@simamkhan81]

Sir plzzz cn u share your watasp....