In the story I only included the "summary" number--that they had achieved 100 F/g, but if you click on the report link you can get the rest of the numbers the researchers report. Here's a few examples from the report:
"single-walled carbon nanotube (SWCNT) thin film and achieved specific capacitance of 33 F/g and a high specific power of 250 kW/kg with an organic electrolyte...improved the graphene synthesis technique and reported a simple activation with KOH of microwave exfoliated graphite oxides and thermally exfoliated graphite oxides to achieve specific capacitance around 200 F/g in organic electrolyte...After laser reduction, the...ultracapacitor offered a specific capacitance of 265 F/g in an organic electrolyte with a wider operating voltage window of 3 V...sheet resistances of the SWCNT and composite thin films were 440.2 and 90.5 Ω /sq at room temperature, respectively...the capacitance of SWCNT and composite ultracapacitors can be estimated as 110 and 40 mF. The thin film of carbon nanostructures has the weight of 1.1 mg and surface area of 1 cm 2. Therefore, the specific capacitances of SWCNT and composites ultracapacitors were calculated as 100 and 36 F/g, respectively...According to Galvanostatic charging/discharging measurements, the specific capacitance of ultracapacitors was approximately calculated as 95 F/g for composites and 28 F/g for SWCNT...
Wow, Colin, I've read a lot of your articles over the years and I can't think of any that I would describe as 'fluffy'. I sympathize with the desire to get hard information, but it also has to be accessible to people that do not specialize in that field. Following an extra pointer to get to the research paper is a small step to take for those who are.
@Larry: Wow, Colin, I've read a lot of your articles over the years and I can't think of any that I would describe as 'fluffy'.
How about cuddly? LOL
I agree with you -- a lot of people just want to be provided with a high-level view, not burried under mounds of techno-babble -- the purpose of thsi type of column is to make folks aware of what's going on -- so long as it then links to the main report with all the numbers, I think it's perfect -- that way the folks who want the numbers know where to go to gorge themselves :-)
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.
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.
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
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.
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.