Just to clear up a perception that I see in the comments, above. An Ultracap is not a direct replacement for a battery. Batteries are electro-chemical ENERGY storage devices and rate limited as to how fast you can charge and discharge them. Ultracaps are POWER devices, the RATE of ENERGY charge and discharge. There is an overlap where they can be substituted for each other. In theory, an Ultracap can be charged (and discharged) instantaneously, and in fact system safety design has to include series resistance (or equivalent) with an ultracap to limit the charge/discharge rate (which you would not do with a battery).
For now, the size of an ultracap to replace a battery leaves something to be desired as well. But where you can benefit from near instantaneous charging (or discharging), it is finding a niche (e.g., the 90 second rechargeable cordless drill). In the mean time, look for hybrid applications with an ultracap as the external interface for instant charging (POWER) backed up by a battery for long life (ENERGY).
Finally, we still have a couple orders of magnitude to go before an ultracap or battery can replace fossil fuel in cars on the basis of power/energy density. And, yeah, the reliability is a risk for now. It's reasearcy, not a product announcement, which means it will be a while before these ever get to where you can buy one.
Mr Johnson, don't take this personally, you are just feeding off what I think is a misperception of society that much invention and discovery is by mistake.
How is any of:
"... when the research team found that both could be easily synthesized by vaporizing a hollow graphite rod filled with a metallic catalyst powder with an electric arc. By thoroughly mixing the two materials to form an ink, the team was able to roll the film onto paper -- a common separator for high-capacity commercial capacitors"... a mistake?
A mistake is when you are carrying Ajak, ammonia, some alumina shavings and a power tool, trip and drop it all in Fido's water dish, and aftertaking the plugged in power tool out of the water and while you are running to flip the breaker back on, Fido trys to get a drink and is vaporized by the stored energy in the water bowl mix except for his right paw and the last third of his tail. That is an accident.
These guys were obviously going down a specific path which lead them to try the above method. Even if it was true the guy who discovered penicilin had the fungus randomly end up in his dish, he wouldn't have recognized what was going on if he wasn't on the path of that discovery.
I think hard work and genius should be recognized for what it is.
It's a great article Mr. Johnson except for that one perception of mine.
With such ultra capacitors and rechargeable paper batteries with high energy density, probably next portable will have one page battery, another page display and third page printed processing unit connected through edge binding!
It will hold true for the vehicle batteries but at the same time on the other hand this will be of benefit in case of sensor networks as well, in very less time the and lights the batteries can be charged to work overnight.
This is what I was thinking when I was reading the article. Going along the article, I get a sense that ultra capacitor may be a complement to the battery. It helps speeding up charging by storing and the ultra capacitor will then put the charge to battery for longer storage. I could be wrong. Nonetheless, I do like the article giving me a view of what's going on. I think it can be a to-be-continued article that the application of ultra capacitor and how ultra capacitor empowering the other technology can further be investigated.
From the density information of these new graphene based supercapacitors it looks like it may be possible to build these supercapacitors in the form factor and the capacity to match the rechargeable batteries that are currently used in EVs.
If that happens then EVs will get a major push as these supercapacitors can get recharged in no time and also are helpful in fast acceleration - thw two factors which are currently lacking in Evs vs the gasolene vehicles
By no means is "fluffy" synonymous with Colin Johnson's journalism! - which I've been reading with great delight over more years than I care to count. Thank you for all that very informative work, Colin.
My problem was that I somehow missed the report link and what was posted was the same in a couple of other sources I'd already seen. The energy density of these devices seems to be most respectable.
I would like to know what the lifetime of these ultracapacitors is versus a rechargable battery. If it is infinite, then we should be moving forward to replace the batteries in electric vehicles with ultracapacitors. I would also like to see common rechargable batteries like AA cell NiMH that can have a drop in ultracapacitor replacement. I would pay more if it would last forever.