IF capacitors could be advanced to the point that a 200 mile range or more would be available in one or two capacitors, why couldn’t there be an exchange system, so the car owner rents the capacitor and pays for the charge therein. Exchanging capacitors would solve the ‘quick refuel’ problem. Yes, that's a possibility. Although I would imagine that such a capacitor would be pretty heavy. Still, with robots to do the work automatically, you might be on to something.
Keep in mind that a capacitor that could store 50 kWh of energy would be nothing to f*** with.
If it is an efficient capacitor, it can also release all of that energy in a second or two, maybe quicker.
I wouldn't want to be within a hundred yards of that particular phenomenon.
The premise of using interchangeable capacitors is based upon being able to discharge them in a measured way so that the sudden surge is not a danger. I was alternately thinking that if lithium ion batteries were in the vehicle, a means to discharge into the battery would give a back up to the battery power such that coming to the end of the battery charge would not strand the driver. Tremendous advancements on capacitors have been achieved with carbon nanotubes. There is even a method of building the containment out of cellulose fibered materials, reducing weight significantly.
ALL advancements in this electric car industry are predicated upon the oligarchy having the reins over the technology, so who knows what may be in the pipeline, or not allowed into the pipeline.