fun fact: you can just _buy_ these. https://www.digikey.com/product-detail/en/maxwell-technologies-inc/BCAP3000-P270-K04/1182-1021-ND/3079285
Granted they're only rated to 2.7 volts because supercapacitors have low voltage ratings, but still. That's about 22 kJ of energy in that thing.
@Felthry hehe, reminds me of when I used supercapacitors for a research project a few years back. massively cool little things.