“For with a supercapacitor, the car can be refueled in less time than itd take to refill your gas tank.”
Let’s say your electric supercapacitor car takes 15,000 Watts to run at some nominal speed. Now run it for four hours, that’s 60 Kilowatt-Hours.
If you were to recharge that capacitor in one second, the power required would be 216 megaWatts.
If it’s a 12 Volt system, you’d need to run 18 million Amperes.
There are practical limits to how fast you can charge a capacitor.
And how would that work out for a charge time of 5-10 minutes? Considering that is roughly the average amount of time it takes to fill up your gas tank at the gas station.