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It's interesting to me that capacitors and batteries are slowly converging. I'm curious which one will end up being the future. My bets are on capacitor's due to their simplicity, but it's still in the air if they'll ever scale high enough in capacity.

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> It's interesting to me that capacitors and batteries are slowly converging.

They are?

Supercapacitors have been around for decades and they store an order of magnitude or two less energy than batteries.

And a battery that runs at 5C isn't new either.

There are some devices that kind of do both internally, but this isn't one of them.

What's the difference? My understanding (perhaps an incomplete one) was that they worked essentially the same way, just optimized for different things (power density vs energy density).

Capacitors and batteries work very differently. Capacitors are made from two conductors separated by a non-conducting dielectric and rely on the behavior of electric fields to charge and discharge. Batteries use the energy from chemical reactions to produce electricity, and some batteries allow the reaction to run in reverse in order to store power.

Wikipedia says that some subtypes of supercapacitors use chemical reactions, too.

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