Very cool tech, and the manufacturing process looks doable as well. :-) Except for us poor mac-heads, how is iTunes going to make me some Graphene?? I was a bit disappointed that there weren't any numbers in the film, so I looked them up: http://www.extremetech.com/extreme/122763-graphene-supercapa... Energy density (storage capacity) does seem to be in range of Lithium Ion batteries, better than some, but still arou…
There also exist hybrid supercapacitors, which use a chemical reaction but act like capacitors. The best use of high-power capacitors is not as a replacement, its as a supplement. Current technology is not quite sufficient, but ideally it would mean that anything under a 20 minute drive could run off just the capacitor, which could(with sufficient infrastructure) charge in under a minute. It's not quite filling up on…
IMO jet engines will never be viable in cars because: cost, complexity, maintenance, noise, exhaust temperatures, and the operating requirements.
The trade-offs to fit it into a car would greatly reduce the benefits over a conventional engine. For example, adding a necessary air filter and exhaust system will see the efficiency drop drastically as you strangle something that requires a free flow of air. Having a power transfer system to a gearbox or a generator/electric motor will also see a great reduction in efficiency. The speed at which a jet turns necessitates a second turbine as a power take-off and hence more losses to bypass.
It's often thrown about that a jet engine is the simplest kind of engine, which is true conceptually, but to get any efficiency, practicality or durability out of it there's a lot of bolt ons that are needed.
I could go on but will cut it short(ish).