tomclarke wrote:Well, here are the numbers.
capacitative storage is a bulk volumetric issue:
energy = integral (E.P+e0E.E)dv where P is polarization. E is field. If er >> 1 you simplify to:
The point is that Emax and P(Emax) are properties of dielectric locally, so you need good dielectric to get good energy density - you can't get round it.
Nanomaterials do better purely because surfaces can have much better properties than bulk, Emax can be much higher for a 1nm surface than is possible for bulk. This BTW is why DL capacitors (ultracapacitors) have much better energy density than ceramic.
For this to work you need a very high volumetric density of surfaces, where the thickness of a surface is typically 1nm or less.
640nm spheres with 10nm thick (20 lattice cells, which is too many for proper nano effects - you expect these on order of 1 cell) gives surface area 5% of total. Assuming 1nm thick 0.5%.
So whetever nanoproperties exist, this structure dilutes them by 20-200X.
=> no-one in right minds would use this structure to get high energy density if mechanism is nano-effects.
You might also imagine some quantum effect where normally local interactions spread out through the lattice (like superconductivity). In this case very high fields kill any such effects in BaTiO3. It is in any case very hard to so how such effects (quantum coherence across lattice cells) could effect something is brute force as energy density.
You can never rule out weird and unanticipated things - but EEStor has published data which very considerable reduce the design space for possible weird thing solutions.
Best wishes, Tom
OK, I'll have to take your word for it about your nanopartical scale.
My impression is that capacitor energy storage density is dependant upon the conductive surface( plate, sponge or electrolyte, separated by a dielectric (insulator) that can resist the voltage between oppositely charged plates. The capacity goes up with area, and perhaps more importantly inversely with the thickness of the dielectric. I think this is basically what you are saying about the dielectric. Any decrease in the size of the strands of a sponge like material will increase the surface area with a surrounding electrolyte (with a dielectric between). At some point the required thickness of the dielectric would become the limiting factor, stalling any more shrinkage. A comparison could be made with a lung. The numerous tiny alveoli sacks greatly increases the aviable surface area for gas exchange, but has a pratical limit based on the membrane thickness, capollary thickness, and the space required for the air channels- or the current carrying elements in a capacitor.
This quote from the link below gives a simple explanation for 'ultracapacitor'
http://answers.yahoo.com/question/index ... 728AABATtW
"In an electrolytic capacitor, the electrolyte is effectively one of the electrodes, and an oxide film is formed between the electrolyte and the other plate. That gives you the capacitance and the dielectric function, too.
In an ultracapacitor, there is a (thin) film formed between each of the electrodes and the electrolyte. The thing that allows the ultracapacitor to reach such great numbers is that each of the electrodes has a greatly increased surface area, with which to react with the electrolyte. Think of the electrode as a sponge, and the electrolyte as water. The surface area of the sponge that is in contact with the water is many times greater than if the water contacted a flat plate of that same overall dimension. Such as it is, comparing a capacitor and an ultracapacitor."
This site shows some of the relationships between capacity, and breakdown voltages.
From my admittedly limited knowledge and shallow research, it sounds like the 'ultracapacitor ' description above is similar to what EESTOR is claiming. If the dielectric is alumina ( aluminum oxide) I wouldn't expect anything exotic in that regard, and surface area gains are probably similar to those described in the quotes above. Without shrinking dimensions to your described few nanometers scale, I don't see how the capacities could exceed what is already out there. Unless, the dielectric can withstand a lot more voltage, therefore proportionately greater joules. BaTi dielectric material could benefit the system some, but again I understand that it is also already in use.
So, my understanding is that if they are not lying, they must have something much different than what is in their patent. Basically, they must have some super dielectric that can resist high voltages with extremely thin layers. Either that, or they've discovered some new physics.
To error is human... and I'm very human.