Capacitors, no doubt, have their place. But that place is not in storing meaningful amounts of energy in consumer applications. Take a 1 Wh capacitor, i.e. a fraction of most cell phone batteries, as an example. To charge it in 20 s, the charger power would have to be 180W - double or triple or more than most laptop chargers. Then there's the current. Assuming a 4 V charger, the current would be a whopping 45A. To bring the current to a more reasonable 2 A, the charging voltage would have to be 90V. Sure, all that is doable, but it involves lugging around a brick of a charger, with some pretty fat wires or a high voltage output.

Ultracapacitors are the dead end. Using similar electrode foils, lithium batteries can offer similar power densities, while still offering magnitudes higher energy densities than ultracapacitors. What's more, lithium batteries can offer similar calendar and cycle life, if they are used in similar circumstances, e.g. microcycling in a temperature stabilized environment. So there is no reason to deal with ultracapacitor development. They cannot offer any marketable advanage over the modern, high-power LiFePO, LTO or NMC cells.

It sounds as if the ultracapacitors are going to be wanted as much on the charging side as the device side. Building something that can supply high amperages continuously (a conventional charger) makes little sense if you're only going to be supplying them for a few seconds to minutes at a time.

This is incredible tech. These leaps are what will kill the gasoline engine.

to physics314; please show us your math...not that i disagree with the amperage. to Rumata; ultracapacitors have their uses. power density versus energy density is what they are good for. example; a bus or large truck takes a lot to get moving - that is where ultracapacitors come in. after they are moving batteries excel. the capacitors can charge much quicker than batteries if the amperage is available, such as in regeneration charging downhill. no matter where capacitors are used, there will probably have to be some amperage limiting devices. these already exist. capacitors can be run in series. if an Ecar runs off 90 volt batteries; then 90/2.5 volt capacitors? = 36 capacitors in series. there would probably have to be a few more for voltage spikes and maybe some voltage limiting as well in the regeneration circuits. so how many capacitors in parallel would it take to provide the initial push for a car, truck, bus, etc.? the article i read suggested 1/4 of the energy density be from ultracapacitors and 3/4 from batteries. for buses in a large city maybe recharge circuits could be built into the pavement for quick capacitor charges at bus stops that are not located at downhill locations (regen via downhill). I'd like to see some specifications on quick charging and regeneration for ultracapacitors before making quick judgements.

The research and development money needs to grow into H2 fuel cells which have by far the best future potential in all areas of performance in transportation this includes increasing the fueling stations.

Lies, lies and more lies. When are people going to learn there is little future in space charge tech? Chemical charge is so, so much better even in peak power, charging/$, /lb, /cubic '. For the same cost, weight, space, li-ion beats both charge rate and output.

Since they say that this 'battery' storage is 'lost' very fast - isn't there some way to 'lose' into some medium that can hold what's lost & itself be storage for the 'lost' charge. Just my ignorant suggestion - but I do know the ignorant sometimes say things that trigger ideas in others ! After all that charge 'goes' somewhere doesn't it ?

I would love to have a set of handheld power tools based on these capacitors!
The more power they can dump in a short time, the more powerful the tool will be, and that's exactly what contractors want and need -- more powerful handheld power tools.
And since they can charge in a minute (while I'm getting a drink or taking a restroom break) and are rechargeable a million times, the entire tool can be manufactured as a single unit -- no more battery packs to deal with and keep charged. This of course makes manufacturing cheaper, and also makes the tool sturdier and stronger for its weight.
Bottom line: these capacitors seem like the perfect solution for handheld power tools of the future.

I can see some very good uses. Good for leveling out energy output from intermittent power sources like wind turbines and possibly solar. Could also be a bridge to charging batteries, where you charge up the capacitor fast and then allow it to charge the battery, so you have a short wait at the charging station. Could also be useful when you need sudden burst of power from a battery, like an electric airplane taking off or sudden acceleration of a car (battery charges capacitor and power burst comes from capacitor).