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Breakthrough In Use of Graphene For Ultracapacitors
Hugh Pickens writes "Researchers at the University of Texas at Austin have achieved a breakthrough in the use of a one-atom thick graphene for storing electrical charge in ultracapacitors. They believe their development shows promise that graphene could eventually double the capacity of existing ultracapacitors. 'Through such a device, electrical charge can be rapidly stored on the graphene sheets, and released from them as well for the delivery of electrical current and, thus, electrical power,' says one of the researchers. Two main methods exist to store electrical energy: in rechargeable batteries and in ultracapacitors, which are becoming increasingly commercialized but are not yet well known to the public. Some advantages of ultracapacitors over traditional energy storage devices such as batteries include: higher power capability, longer life, a wider thermal operating range, lighter, more flexible packaging and lower maintenance. Graphene has a surface area of 2,630 square meters, almost the area of a football field, per gram of material."
Is this another factor of 2 on top of EEStor's still-unproven claims? How many more breakthroughs is it gonna take before something actually happens?
Some advantages of ultracapacitors over traditional energy storage devices such as batteries include: higher power capability, longer life, a wider thermal operating range, lighter, more flexible packaging and lower maintenance.
By contrast, two advantages of batteries are 1) vastly higher energy density, and 2) the fact that they exist.
Mac users, however, will still be getting 1 1/2 hour of unbuttplugged life, tops :)
2D area vs mass. What that statement was trying to get across was that graphene is so thin that you could almost cover a football field with only a gram of it. Think of spreading cream cheese on a bagel. You only have a gram of cream cheese, though, so you have to spread very, very thin. Except the bagel is the size of a football field, so you have to spread it even more ridiculously thin: only an atom thick. Now instead of cream cheese it's carbon atoms.
"A witty saying proves nothing." - Voltaire
I found this image from Nature magazine useful in imagining how 1 gm of graphene can have such a large surface area..
http://www.nature.com/nature/journal/v427/n6974/fig_tab/nature02311_F1.html
"Laziness is an optimisation protocol"
A relative of mine's Panasonic Toughbook CF-W5 is rated 11 hours and actually gets her 5-6 hours of word processing and internet on battery. Maybe you should try better-quality laptops.
Depends; we don't yet know how to commercially make graphene. This is a shame because in addition to ultracapacitors it could also be used to make integrated circuits. It's the same problem as with nanotubes; lots of great uses already found, now we just need to figure out how to make them.
// MD_Update(&m,buf,j);
Yes, massively folded. Similar technology has been in used for many years to produce multi-Farad 'dime' capacitors, whos surface areas start around the size of a tennis court and go up from there.
These sorts of capacitors have very high capacitances (in the multiples, even tens of Farads) and a 20-50 year life span (or longer depending on how they are built), but also tend to only be able to be charged to fairly low voltages (3v, 5v, etc), and also have fairly high internal resistances (though this might be different for the newer Graphene-based caps), limiting the discharge rate.
This means they won't be replacing batteries any time soon, but the advances we're seeing are pretty cool.
We mostly use these things to run real time clock chips and provide backup power for static ram... i.e. very low current applications.
-Matt
Surface area is the size of a football field, but because it is very thin it can be rolled up in to something very small.
Think about a roll of toilet paper. When rolled up it is about 10cm x 10cm x 10cm. If you roll it out it might be 50m long.
45 miles per gallon, which I say is not bad...
If 1 gram of graphene has the surface area of a football field, what's the surface area of a football field of graphene?
One football field, of course. They're both units of area. Now, if you were to ask what the surface area of a VW-Beetle-equivalent of graphene is ...
The surface of your brain is pretty thin to, ya'know. At least I know my brain doesn't 'lose capacity' when I go over a speed bump. Like the brainm the single-atom-thick part of the proposed ultracapacitor won't be out to the open air.
Look into how capacitors work. It's capacity is largely based on the surface area of internal parts. You get that by making things thin. Thin is huge for capacitors, even the normal kind you have in the computer you used to type that post. Capacitors are all wound up inside and packed nicely. They *do* break on occasion and get icky gooey stuff everywhere, but it's not exactly so fragile as to be caused by a speed bump. Otherwise we'd have a lot of dead cars on the road.
"A witty saying proves nothing." - Voltaire
Human resource usage expands to consume all available resource...
That is the history of humanity in one sentence. In fact, it can be generalized to all life.
Deleted
That would be a football field to the power of a football field.
I think a more relevant question is: if 1 gram of graphene has the surface area of a footbal field, what weight are the football players? And is that "football" or "Soccer"?
If telephones are outlawed, then only outlaws will have telephones.
Ultracapacitors may have proven brilliant usages (especially in transport and electricity storage) but is anyone else nervous about being around that degree of stored energy?
As a teenager I was slightly injured by a 50-year-old 3300mfd cap I'd salvaged from a valve radio, which went off like a small bomb despite only holding 12 volts at the time. I for one would treat an ultracapacitor as a potential source of devastation until proved safe by a long period of use...
I have been a user for about 10 years. This ends Feb 2014. The site's been ruined. I'm off. Dice, FU
So why not just use toilet roll as a capacitor?
But you wouldn't even be able to taste the carbon on your football field that way. Seems silly to me.
So why not just use toilet roll as a capacitor?
The cylinder capacitors that handle the bigger charges most of the time pretty much look just like that if you crack them open.
Liberte, Egalite, Fraternite (TM)
Because it doesn't have to layers that are insulated against each other?
However, if you're talking about two toiled rolls, soaked in electrolyte, with an insulator between them, rolled up and packaged nicely, then yes, you can use that as a capacitor (we'd all be thrilled about a capacity measurement and some pictures when you try it out, please?).
I think we all know it depends on what you're doing with those hours. Lets put our dicks back in our pants now.
Don't worry that the Graphene layer would rip. It's a very, very strong material and the connections between the atoms are strong conjugated double-bonds.
This is the same structure as in Carbon Nano Tubes and Fullerens (C60), just flat (and not cylindrically or spherically rolled up).
The problem to implement Graphene based technologies is rather the synthesis of it, since it's not yet easily possible to create a homogeneous Graphene layer on a large area (i.E. at my Applied Physics institute they create Graphene layers that are not even 1 mmÂ).
First poster didn't seem to. Times were when you only got 1.5 hours of word processing time, and these days people have their wifi enabled all the time. Anyone with a mobile phone will know that that is a major drain on the battery. We're getting the same battery life as before, but we're able to do much before in that time.
By the time affordable ultracaps everyone will probably be complaining of 'only' 11 hours solid gaming usage on their laptop.
which is totally what she said
Forget Rhode Island or Texas... always use Wales.
http://www.simonkelk.co.uk/sizeofwales.html
Don't be apathetic. Procrastinate!
It's capacity is largely based on the surface area of internal parts.
It's also largely based on the inverse of the distance between internal parts. And this distance also decreases when you make things thinner.
Thin is huge for capacitors,
Yep, it's huge^2, even, since you're increasing surface area and reducing the distance if you make the internal structures thinner.
http://www.quantumg.net/eeepc.txt
How we know is more important than what we know.
If you wanted a thin layer of carbon, wouldn't it be easier just to toast the bagel?
I wonder how practical is graphene capacitor used as a memory storage cell compare to SRAM or DRAM we have today.
Err ... you do know that one of the main differences between SRAM and DRAM is that the latter uses a capacitor (and fewer transistors) than the former per memory cell, and therefore requires to be refreshed occasionally (hence "dynamic", as opposed to "static" memory which will keep its contents as long as it is supplied with power)?
I'd say that graphene capacitors are as uninteresting as it gets as far as memory technology goes, sorry.
American football, probably. No reason to cover a soccer or rugby field with cream cheese, that I can think of.
I prefer rogues to imbeciles because they sometimes take a rest.
I just tried it. I don't have the pictures anymore, but the explosive capacity is high enough to take out a digital camera and a kitchen table. Pretty impressive, those toilet paper supercaps.
USE HOT GRITS WITH STATUE OF NATALIE PORTMAN (NAKED AND PETRIFIED)
If his fetish is, say, truckers and fat mexican grannies with mustaches, do you still want to be the cameraman?
Must... resist... urge... to verify... Internet Rule 34....
Ghaaa !!! 22k+ pages found. The Google, it doesn't do nothing.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
My experience has been that they are not nearly as absorbent.
Or until we invent fertilizer (18th century)...for food
Or until we invent pesticieds/herbicides...for food
Or until we invent underground farming...for food
Or until we invent land reclimation...for land
Or until we invent skyscrappers...for land
Or until we invent seasteading...for land
Or until we invent lunar colonies...for land
Or until we invent large dams...water, food and power (oil)
Or until we invent water treatment...water
Or until we invent reverse osmosis distillation...water
Or until we invent atmospheric condensers...for water
Or until we invent nuclear fission...for power (oil)
Or until we invent fusion...for power (oil)
Or until we invent photovoltaics...for power (oil)
Or until we invent bio fuels...for power (oil)
Or until we invent direct CO2 conversion to hydrocarbons...for oil (from power)
and a big one is:
Or until we invent a trully good electrical battery, one that stores a lot of energy, has high power density, does not wear out, does not use environmentally harmfull components and is cheap (something like these graphene supercapacitors will be under mass production)...for oil
My point is simple. Humanity ran out of resources about 20,000 years ago. We are designed to be hunter/gatherers. The earth can only support a few million hunter/gatherer human beings. It was only through the invention of agriculture and other technologies that we are able to continue. While we will probably ALWAYS have some resource limitation (probably power) there are technologies that exist now that if used can prevent any Malthusian collapse for the indefinet future.
I wonder what the ESR of a 1-atom thick layer of graphene is. I can't imagine it's that low. That kinda blows it out of the water for applications that have big current transients (like DC/DC controllers, parallel RAMs, anything with a lot of parallel switching I/O, really)
The fact of the matter is, it takes "X" number of joules of energy to move your typical car 300 miles.
Whether that energy is stored in a tank of gasoline, a capacitor, batteries, or a spinning flywheel, you still have X number of joules of energy that have to be safely stored and protected against unrestrained liberation.
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
No, capacitors don't have to. In fact even the tiny capacitors you can get at radio shack hold enough power to fry most electronics if it were released at once.
Capacitors only release all the power they hold at once when they fail catastrophically...then they blow up.
However the output voltage of a cap is related to the energy they store so as the output voltage must be adjusted as the capacitor discarges to maintain usable voltage. By oncreasing the resistance in the circuit you can slow the discharge rate of a capacitor to usefull levels.
Look up introductory electrical engineering stuff, searching for RC time constant and RC curves. This appears to be a good page.
The overall idea is that charge cannot move instantly through a resistance. Think of a capacitor like a bucket of water, and the resistor a hose hooked to the bottom of the bucket. The bucket can drain only as fast as the hose is wide. And the less water there is in the bucket, the slower it will drain (since there is less weight/pressure pushing on the water at the bottom of the bucket where the hose is.)
Weaselmancer
rediculous.