Is there a theoretical limit to energy density of a capacitor? eeSTOR had a lead on a dialectric of around 20,000 -- doped barium titanate. I never figured out if it was a long con game or they had a real product that didn't turn out.
I don’t know. The issue with questions like this - through no fault of your own - is that there are different types of capacitors, and it’s difficult to find any source that looks into the theoretical capabilities of all types.
Let’s start with the basics for those of us (like me) who know very little about this topic. There are three primary parameters that influence the energy density of a capacitor: the properties of the dielectric used, the geometry of the capacitor, and the breakdown voltage. (Breakdown voltage is the voltage at which a dielectric becomes conductive.) Geometry, of course, can be easily (relatively speaking) controlled, it’s the dielectric and the breakdown voltage that I’m unsure about.
If a theoretical limit were to exist, it would depend, largely, upon any theoretical limit of these two parameters. And I don’t know if any exist.
I was able to find this article, which attempts to calculate energy density limits, but it does so on a material by material basis for a select number of materials, and admits there are some flaws with their approach. All other articles I’ve found refer to either specific materials, or specific types of capacitors (electrochemical double-layer capacitors, integrated capacitors, thin film capacitors - specifically tantalum pentoxide, and so on.)
Additional Sources/Further Reading: ( 1 ) ( 2 ) ( 3 )
I admit I’m a little out of my depth here - if anyone has any more information about this question, or if I’ve explained something incorrectly, please chime in!
