Superconductor, superinsulator and supercapacitor

[Aghanim]

Superconductor is something that can conduct electricity perfectly, and superinsulator is something that cannot conduct electricity perfectly, and capacitor can be build from conductor - insulator - conductor , so if we use superconductor - superinsulator - superconductor, can it store energy near-infinitely, at least until one of them reverts to normal? How much it can store? What properties will this 'supercapacitor' have?

And yes, superinsulator does exist: http://en.wikipedia.org/wiki/Superinsulator

And supercapacitor name is already taken by double layer capacitor, but I don't have better name for this

Edited January 1, 2015 by Aghanim

[YNM]

A capacitor doesn't have flowing currents in it ; it merely just storing it, then appearing as if it have a capacity - superconductor would give the same result with usual conductors. You'd just need to get the superinsulator maybe so there's no way a shortcut could happen. Then give it a really high potential difference - I don't know what for through !

[Nuke]

i dont think using super conductors/insulators in capacitor design would be of much use.

super insulators may decrease self discharge rates of the device, meaning that it would not have a tendency to loose charge when not being discharged. however there will still be self discharge at the terminals. insulators used in wiring in the circuit, pcb substrate, even the air, all will allow a self discharge path (all be it a slow one). it might help out-of-circuit energy storage, but almost nobody uses capacitors in this way. doing so would also raise safety concerns because capacitors like to discharge themselves as fast as they can, so dont lick the terminals (damn it jeb) or you might die.

super conductors might increase discharge rate and reduce heat generated from rapid discharge. this might help high energy applications like capacitor banks for rail guns and fusion reactors. you might use super insulators for this application as well, since caps, switching circuits, etc, may all be held at cryogenic temperatures anyway. but then again its not going to cost you a whole lot of extra power to keep those banks topped off. its a similar problem to boiloff in lox tanks, its going to need to be constantly topped off to keep up them full, but this is drops in the bucket when compared to filling the tank.

so either way, its not a revolution in capacitor design. not so much as nanomaterials has been. denser packing of the layers in a capacitor helps to improve capacity vs size at a given voltage. so you can get more out of smaller devices.

Edited January 1, 2015 by Nuke

[K^2]

Superinsulators have pretty low critical voltage. Actual capacitance of your "supercapacitor" will not be at all super.

[Idobox]

Superinsulators have pretty low critical voltage. Actual capacitance of your "supercapacitor" will not be at all super.

Let me develop on that.

The limit on how much energy you can store in a capacitor is the breakdown voltage, where the insulator stops insulating, and you get a nice spark usually accompanied by smoke.

This breakdown voltage is a function of insulator material and thickness. If you use a thicker insulator, you get a higher breakdown voltage, but also a lower capacitance. in the end, the quantity of energy you can store is proportional to the volume of insulator used. As said, superinsulators will leak less, but keeping a capacitor charged for hours is already possible.

What you want for better capacitors are materials with very high breakdown voltages.