That's about one Tsar Bomba of energy.
This is too high by 4 orders of magnitude. 100 kWh is a larger than average battery capacity for a contemporary BEV [1]. That's 2000 MWh for 20,000 vehicles charging from empty (modulo charging inefficiencies). 1 megaton is 4.18 * 10^15 joules or 1,162,000 MWh [2] while the Tsar Bomba had a yield of at least 50 megatons as tested [3]. So charging 20k electric cars from empty requires about 0.003% as much energy as the Tsar Bomba released.
[1] https://en.wikipedia.org/wiki/Tesla_Model_S#Battery
Still, if you look at power, that much energy moving in 5 minutes is about 24GW. That's massive. Unless I'm wrong with numbers again :P.
Graphene has seemed to be the key to rapid charging while maintaining temperatures for over a decade. The challenge was always getting enough usable graphene at low cost without mining.
I'd like to see what kind of electrical infra you need to (even partially) charge 20k cars in 5 minutes.
That's about one Tsar Bomba of energy.