A prototypical capacitor consists of two electrodes in parallel separated by a nonconducting dielectric material. What is the difference between a conventional capacitor and a supercapacitor?
It seems that conventional capacitors usually have solid dielectric materials, like polymer films, ceramics, or glass. But is this always the case? (I guess one possible exception is an electrolytic capacitor, such as an aluminum electrolytic capacitor. But in that case, it seems that it is an electrode that may be in the liquid phase, and not necessarily the dielectric separating the electrodes.)
Supercapacitors are more technically known as electric double layer capacitors (EDLCs). An electric double layer forms at the interface of the electrode and the dielectric. It seems that in a supercapacitor, the dielectric is usually a liquid. But is this always the case?
Can it be said that the difference between a conventional capacitor and a supercapacitor is that
- a conventional capacitor has a solid dielectric, whereas
- a supercapacitor has a liquid dielectric?
I would appreciate it if anyone could share an academic resource -- book or journal article -- that explicitly states the difference.
Incidentally, the journal article here (Olabi, Energy, 2021) states:
Due to solid dielectric between the electrodes, supercapacitors store energy by means of an electrolyte solution between two solid conductors.
I wonder if they made a typo in that sentence.