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I've been researching into the development of electrical power units for Automotives (motorsports in particular, as I participate in my Uni's Formula Student team) and have started by looking into the applications of supercapacitors for energy storage purposes. I'm seeing a pattern, were all supercapacitors currently on the market are rated at max, 2.7V (with some pushing close to 3.0V) without any real reason why.

Compared to standard electrolytic capacitors (which I've viewed types that can withstand 1000V comfortably) I understand that the construction is different however I'm not exactly sure why this has such a drastic effect on the max voltage. Would there be anything on the quantum level that stops a supercapacitor having a rated voltage greater?

My suggestion is that maybe the Helmholtz regions that hold the capacitance has an effect on the maximum voltage that can be but I'm not entirely sure (just an educated guess)

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    \$\begingroup\$ The dielectric layer is thinner, and can't be made thicker with the current technology of "super capacitors". \$\endgroup\$
    – Olin Lathrop
    Commented Dec 20, 2015 at 16:42
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    \$\begingroup\$ @OlinLathrop do you happen to have sort of resources or recommended material that goes into detail in the making of a supercapacitor? Specifically the effects the dielectric layer has to voltage as you've brought up the relation. \$\endgroup\$
    – Kristopher Rahim
    Commented Dec 20, 2015 at 16:47
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    \$\begingroup\$ you can't use supercaps in EF1 anyway, they are meant to have an high energy density but low max output power... And you need high output power, and "medium" energy density \$\endgroup\$
    – Vladimir Cravero
    Commented Dec 20, 2015 at 17:01
  • \$\begingroup\$ @VladimirCravero can you elaborate on 'EF1' for me, please? If that's formula student related, I checked the UK regulations and it's acceptable design for energy storages. \$\endgroup\$
    – Kristopher Rahim
    Commented Dec 20, 2015 at 17:06
  • \$\begingroup\$ EF1 is electronic formula 1, not sure if it's widely used. I'm sure you can use supercaps but I am not sure they would be any good. They have a pretty high series resistance and that's not good. LiPo batteries are specifically built to sustain high current discharges instead. \$\endgroup\$
    – Vladimir Cravero
    Commented Dec 20, 2015 at 17:09

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Super Capacitors are a sort of cross between electrolytic capacitors and batteries.

see wikipedia article

Unlike in electrolytics, where you can build the insulating film up to an arbitrary thickness by applying a high voltage, in supercaps the insulating film has more to do with the polarisation layer of a battery, so has a hard upper voltage limit.

The lifetime of the system is also somewhere between batteries and electrolytics.

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  • \$\begingroup\$ So this doesn't seem likely to change in the near future then? Is there a way you, that I can simulate what happens when I draw more than the rated voltage and see what that does to the lifecycle? \$\endgroup\$
    – Kristopher Rahim
    Commented Dec 21, 2015 at 6:56
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If you google it, they do make 10v 2200F supercaps... beasts! Afrotechmods on YouTube got ahold of a few of these and they sure do let the sparks fly.

I only put this as an answer because I do not yet have 50 rep so I cannot comment.

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  • \$\begingroup\$ Though I've a feeling that supercap is in fact, just 4 supercaps rated at 2.5V connected in series \$\endgroup\$
    – Kristopher Rahim
    Commented Dec 21, 2015 at 7:01
  • \$\begingroup\$ They still exist, don't they? :) \$\endgroup\$
    – nkeck72
    Commented Dec 21, 2015 at 16:43
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Similar to batteries, you can have whatever voltage you want by having someone put "cells" in series with a balancing system, most commonly you can get "18 volt" ones to sort of simulate a 12 volt battery.

Each cell is limited for in voltage for reasons similar to battery cells, as involves chemical reactions helping to simulate a conventional capacitor.

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Super capacitors are mainly used for Real time application monitoring solutions. means wherever you need RTD, you can use super capacitors to get long lasting energy.

Mostly RTD application uses microcontroller and microcontrollers are fairly rated for 3V applications. I feel that's why most of the available mass super capacitors are rated for 3V applications.

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