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Thread: absolute insulator or dielectric

  1. #1 absolute insulator or dielectric 
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    There is an article:http://www.reactivereports.com/73/73_1.html in
    which discovered superinsulation ability is described.I really interested to know
    if there could be such thing as absolute insulator or dielectric which would be able to withstand trillions of volts on square cm, or such thing is impossible in theory?
    If we theoretically get such a substance,how energy dense capacitor could we create?Will its energy density surpass that of hydrocarbon fuels or not?


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  3. #2 Re: absolute insulator or dielectric 
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    Quote Originally Posted by Stanley514
    There is an article:http://www.reactivereports.com/73/73_1.html in
    which discovered superinsulation ability is described.I really interested to know
    if there could be such thing as absolute insulator or dielectric which would be able to withstand trillions of volts on square cm, or such thing is impossible in theory?
    If we theoretically get such a substance,how energy dense capacitor could we create?Will its energy density surpass that of hydrocarbon fuels or not?
    An insulator and a dielectric are not quite the same thing, but usually one is the other.

    An insulator is characterized by the voltage gradient that can be sustained before breakdown occurs.

    A dielectric is characterized by the relationship between the E and D fields, and that characteristic is what determines capacitance and the ability to store energy as a function of voltage.

    The measure of a capacitor is not in terms of voltage per unit area, so that part of your post is not comprehensible.

    Capacitors are generally not particularly effective for storage of significant amounts of energy. But since you place no bounds on the dielectric constant, the sky is the limit. Finding this miraculous material might be a tad difficult.


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    Maybe there could be something by anology with superconductor?If there exist
    superconduction maybe there is also superresistance?
    I whish to know if there is some other physical limitations in supercapaciters even
    if we have superinsulator?One guy expressed his mind on forum that energy storage which is based on intermolecular forces bending (capacitor) principally can't be greater than one that is based on intermolecular forces breakdown (burning fuel).
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  5. #4  
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    Superinsulators still don't solve two of the issues with supercapacitors, namely dielectric absorption and the low voltage they can provide. Also, the discharge voltage is not constant, so in some applications you cannot actually use all the energy stored inside it.
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  6. #5  
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    Quote Originally Posted by Stanley514
    Maybe there could be something by anology with superconductor?If there exist
    superconduction maybe there is also superresistance?
    I whish to know if there is some other physical limitations in supercapaciters even
    if we have superinsulator?One guy expressed his mind on forum that energy storage which is based on intermolecular forces bending (capacitor) principally can't be greater than one that is based on intermolecular forces breakdown (burning fuel).
    Energy storage in a capacitor is NOT based on "intermolecular forces bending" whatever that is.

    It comes from the storage of charge on the plates, and the potential difference between the plates.

    The energy of a capacitor is . The dielectric does two things. 1) It affects the relatinship between and and 2) it affects the voltage at which breakdown occurs and the capacitor discharges internally.

    If you had a "perfect" insulator then there would be no limit to the voltage that could be supported by the capacitor and therefore no limit to the energy storage capacity. This is quite independent of the properties of the material as a dielectric.

    Go read a book on electromagnetic theory and understand the physics of a parallel plate capacitor. You might try Engineering Electromagnetics by Hayt. It is a fairly easy book and covers this subject pretty well. The classic text is Jackson's Classical Electrodynamics which will go into more detail on the basic physics but is quite a bit more demanding of the reader.
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    Usually,I ask questions on details which aren't explicitly covered in books.
    I have no access to very specialized books and not going to receiver Ph.D. degree in physics either.As I could understand there is not too many great specialists on this forum.
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  8. #7  
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    Quote Originally Posted by Stanley514
    Usually,I ask questions on details which aren't explicitly covered in books.
    I have no access to very specialized books and not going to receiver Ph.D. degree in physics either.As I could understand there is not too many great specialists on this forum.
    "The questions that you asked are covered in a great many books, introductory books on electrodynamics through advanced books on that subject. I suggested two of them.

    I don't know what you are seeking, but your questions were answered.
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  9. #8  
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    If you had a "perfect" insulator then there would be no limit to the voltage that could be supported by the capacitor and therefore no limit to the energy storage capacity.
    I think, not everything that simple, and there are still serious limits to energy density.Coloumb forces between electrons will ultimately become too strong and you would not be able to squish them together.In this regard I whish to know if there could be such designs of capacitors as: 1)One type of charge capacitors.For example, it contains only one plate with electrons and discharges into the ground through electric motor.2)Ferroelectric capacitor.It does not contain a free charges and works similar to ferroelectric memory.Electric potential is applied and causes permanent polarisation.After that energy is drawn from capacitor when needed.

    There are statements that in some ferroelectrics such as Barium Titanate dielectric
    permittivity approaches infinity at temperature close to Curie point.
    http://www.kau.edu.sa/Files/320/Researches/35550_42.pdf
    For example in Barium Titanate it's close to 120 centigrads.I think with current technologies it's quite possible to maintain that temperature constantly.
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