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According to wikipedia, commercially available super-capacitors in 2010 can store 30Wh/kg, with 85Wh/kg achieved in a lab in 2011.

Have any theoretical calculations been done to show what can be achieved as an upper limit to super-capacitors?

Qmechanic
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Mozibur Ullah
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1 Answers1

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Working on this problem myself. Limiting factor is specific surface area (dissociated ion attachment sites) and breakdown of the dielectric (general capacitors use dielectric that have high voltage breakdown levels, supercapacitors have low voltage breakdown levels). As far as the surface area limitation, supercapacitors use ion chemical potential, the more ions that it has surface area for, the more potential energy it can store on each electrode.

Inputs to calculation: -total surface area of electrode -average surface area taken up by each dissociated ion (changes depending on the ion) -charge of the ion (assuming there are inexhaustible numbers of ions in electrolyte)

Output: -divide total surface area by average surface area taken up by each ion. This gives number of attachment sites, multiply by charge of the ion. This should give specific energy for a given ionic solution (electrolyte).

As far as specific power, I'm guessing it depends on 1. electric potential between electrodes 2. distance between electrodes 3. pore size of separator (and/or electrode porous coating pore size)

Source - an educated guess

Nolan
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