Tutorial 3-How to calculate capacitance of a supercapacitor
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- Опубликовано: 18 сен 2024
- This video shows how to calculate the capacitance of a single capacitive electrode in a 3-electrode device.
The title video of the EChem Channel is credited to: Bilen Akuzum and Simge Uzun.
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We are trying to better, always. So, for any other potential issue, please let us know. Thanks!
Thanks from Pakistan
Also teach to calculate capacitance from GCD curves and to compare values of capacitance from CV and GCD data. Thanks for the efforts
It is similar to CV method: integral it.
What us Cv formula for finding cap for 3 electrode ?
Very helpful. Thank you!
So glad!
how you calculated the capacity of the battery-like device at 3.4 to 3.0 V (from the GCD curve)1866 F/g??
Really thanks for these videos, could you please tell me how do you calculate the 1019 Wh/kg?
Please watch tutorial 14 for your question. I don't think 1019wh/kg is mentioned in the video, and it seems such high energy density is not yet achieved in supercapacitor as far as I know.
Obviously she did mentioned 1019wh/kg in this video. The idea she want to convey in the last few minutes in the video is "For battery-like materials, we can't treat the faradaic specific capacity of the material as its specific capacitance throughout the whole voltage range". That means the 1019 Wh/kg is calculated in a wrong way as "E=0.5*C*V^2". For example, you use 1866 F/g as its specific capacitance and 2V as the voltage range (2.0 - 4.0 V vs Li/Li+), the E = (0.5 * 1866 * 2^2) / 3.6 = 1037 Wh/kg.
How is 1/2CV^2 energy density? In what units are we measuring C here?
C is capacitance, whose unit is Farad or coulombs per volt. Energy = integration of capacity over potential. For a battery that has a flat potential vs capacity, E = QV. For supercaps that have a slopping potential vs capacity, E = 1/2QV (triangle shape) and because Q = CV, we have E = 1/2CV^2. You may understand this better by checking out Figure 2 in Fleischmann, et al. Chemical Reviews, 2020, 120, 6738-6782.
Nice video. Why we can't select potential range from -ve to +ve in two electrode symmetric supercapacitors? Can you please elaborate reason for this?
Thanks. That is because if the cell is charge from +V to 0 then to -V, the polarization of the two electrode is simply switched (no extra energy is actually stored/released).
支持老乡。
Thanks!
Hi, when using the formula for capacitance in non-linear GCD, the integral 1/V(t) goes to infinity as you approach 0. So, if your potential window goes from +v to -v you will get very large capacitances. Is there any other way to calculate capacitance from non-linear GCD? Thanks!
Hi Andres, we usually approximate the capacitance of non-linear GCD with the linear regression of the most linear part of the GCD curve.
I have another question. If I have material that work from 0 to +1 V, and also from 0 to -1V. In case of doing symmetric device what potential should I use? is it from 0 to 2V?? and what law should I use to calculate the capacitance? is it the same law from GCD but divided with 2?
Hi! Did you find the answer to your question? And are you working with SCs now?
Hi, when calculating the capacitance from your CV curves do you not have to take into account both the charge and discharge step. Which means you may have to divide everything by 2? Cp=Area/(2×(S.R)×∆V) Quite curious to know more on this, thanks!
Hi. We usually calculate the discharge capacitance. However, it depend on how you define a charge and discharge process. Just make sure the Coulombic efficiency cannot be larger than 100%.
@@EChem_Channel so wouldnt the area under the curve be composed of both the CV's charging and discharging voltage steps? Once again resulting in it being divided by 2 if you were only considering the discharge step?
respected sir pleas GCD AND Eis b explain krn
please use these laws
i = a(v) power b
i(V) = Kv + k2v power 1∕2
calculate capacitve and non capacitive charge by these equation and complete mathematically step how can do in origin or any other App to solve this problem. im beginner in this field please help me in this regards
We will find the chance to talk about b value in the future video.
How to get 1019 Wh/kg?