Tesla just filed a patent for a new battery chemistry out of their Nova Scotia R&D facility that supports faster charging and superior longevity. I expect batteries to become supercapacitors faster than supercapacitors become batteries.

If supercapacitors have any role, it’s at EV charge stations to reduce demand charges from utilities. VW just agreed to buy a whole lot of Tesla batteries for this purpose at their Electrify America charge stations. Space is not an issue, as you can bury your storage under the charger stalls.