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Breakthrough In Use of Graphene For Ultracapacitors

kdawson posted about 6 years ago | from the high-credit-limit dept.

Power 250

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."

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Still... (1)

UnixUnix (1149659) | about 6 years ago | (#25035529)

Laptops, however, will _still_ be getting 1 1/2 hour of unplugged life tops :(

Re:Still... (3, Funny)

Anonymous Coward | about 6 years ago | (#25035545)

Mac users, however, will still be getting 1 1/2 hour of unbuttplugged life, tops :)

Re:Still... (0)

Anonymous Coward | about 6 years ago | (#25036931)

You owe me a new keyboard or a tip for getting coffee out of one

Re:Still... (2, Informative)

Anonymous Coward | about 6 years ago | (#25035619)

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.

Re:Still... (2, Funny)

Anonymous Coward | about 6 years ago | (#25035963)

I think we all know it depends on what you're doing with those hours. Lets put our dicks back in our pants now.

Re:Still... (2, Insightful)

somersault (912633) | about 6 years ago | (#25036017)

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.

Here's the deal (5, Insightful)

Colin Smith (2679) | about 6 years ago | (#25035697)

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.

 

Re:Here's the deal (5, Insightful)

srussia (884021) | about 6 years ago | (#25036087)

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.

Agree with your first statement. The difference, however, between humanity and other forms of life is that humans increase available resources in order to be able to expand usage.

Re:Here's the deal (-1, Troll)

Anonymous Coward | about 6 years ago | (#25036231)

... humans attempt to increase available resources ...

Fixed that for ya.

Re:Here's the deal (3, Insightful)

lisaparratt (752068) | about 6 years ago | (#25036351)

You think our atmosphere always had this much oxygen in it?

Re:Here's the deal (3, Informative)

HungryHobo (1314109) | about 6 years ago | (#25036797)

No but the organisms which produced the oxygen first probably weren't the ones which needed it to survive, oxygen was waste, a poison to them.

Although there are animals and plants which by one means or another make more space for themselves to live in.

Re:Here's the deal (3, Insightful)

HungryHobo (1314109) | about 6 years ago | (#25036107)

We don't seem to have expanded to use all oxygen yet, we don't seem to have used up all the salt water, both are freely available to a great many people.

Human resource usage expands to quite a high point but to assume it's infinite is a little presumptuous.

It was assumed that the human population would continue to increase exponentially but in some developed nations we're seeing a birth rates drop below 2 children per couple.

People multiply insanely when the chance of their children reaching adulthood is low, people try to obtain stupidly large amounts of resources when resources are scarce.
Average resource usage may not increase forever. It'll probably still has a way to go but I can see the average leveling out at some point.

Re:Here's the deal (0)

Anonymous Coward | about 6 years ago | (#25036589)

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.

Why can't I manage to fill my 1TB drive full of porn then?

Re:Here's the deal (2, Funny)

NotBornYesterday (1093817) | about 6 years ago | (#25036807)

You're obviously not looking in the right places, or you are extremely picky, or your tastes in porn run to a very narrow, seldom-seen set of fetishes.

If it is the latter: "seldom-seen fetishes" good news! You have found an under-served area of the over-saturated porn market, and are in a position to make a fortune by developing and operating a site serving that particular segment. Congratulations, and good luck. Let me know if you are looking for a cameraman, and/or MySQL admin with some PHP experience.

Re:Here's the deal (4, Funny)

TapeCutter (624760) | about 6 years ago | (#25036833)

Speaking of expanding..."Graphene has a surface area of 2,630 square meters, almost the area of a football field, per gram of material."... As a young man I plugged a large 12v capacitor into a 240v outlet because I thought....hmmm....if a 9v battery make that big a spark....Ten minutes later I had it screwed to a wooden booard with a domestic power cord attached....KABOOM!!!....my room was covered in sticky silvery confetti...you get where I'm going, graphene would go off like a fuel air bomb! All this leads me to the conclusing that .....

If you car has a graphene ultracapacitor, resources consume you! /sorry

Re:Still... (1)

Alioth (221270) | about 6 years ago | (#25036463)

My 4 year old PowerBook still gets 3 hours, unplugged.

EEStor (4, Interesting)

paul248 (536459) | about 6 years ago | (#25035531)

Is this another factor of 2 on top of EEStor [wikipedia.org] 's still-unproven claims? How many more breakthroughs is it gonna take before something actually happens?

Re:EEStor (1)

dvh.tosomja (1235032) | about 6 years ago | (#25035747)

Come on, "Site under construction" used to be fun in 90's

Re:EEStor (1)

QuantumG (50515) | about 6 years ago | (#25035749)

There's 10 years from lab to product.. at least.

Re:EEStor (5, Interesting)

smilindog2000 (907665) | about 6 years ago | (#25036423)

No. This isn't even close to EEStor's claimed energy density. I personally put EEStor in the BS bucket a long time ago, but last week I found some very interesting news on wikipedia's EEStor page [wikipedia.org] : competitors. It seems that several companies now have patents on materials they claim are similar in energy density to EEStor's claims. We may not get ultra-cheap batteries for electric cars any time soon, but at least the raw science seems to be real.

Re:EEStor (3, Interesting)

JamesP (688957) | about 6 years ago | (#25036947)

Yeah, except there are also patents on glass pyramids that keep razors sharp, cures cancer or something like that. And don't forget the patents on playing with your cat with a laser pointer.

When people say anything can be patented, they're pretty much spot on.

How? (1)

topnob (1195249) | about 6 years ago | (#25035533)

Sorry but how does this work? "Graphene has a surface area of 2,630 square meters, almost the area of a football field, per gram of material" so its actually the size of a football field?

Re:How? (1)

jkenneth24 (962795) | about 6 years ago | (#25035571)

im thinking its because graphene is thin -- one atom thin... i guess when you stack pairs of them, you get a football field's worth of surface area.

Re:How? (5, Informative)

Paradigm_Complex (968558) | about 6 years ago | (#25035585)

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.

Re:How? (1, Insightful)

cryptoluddite (658517) | about 6 years ago | (#25035607)

Generally things that are one atom thick are much more fragile than things that are millions of atoms thick. When they get this working in cars and not 'losing capacity' aka frying you when you go over a speed bump it'll be a pretty good replacement for batteries...

Re:How? (1, Interesting)

Anonymous Coward | about 6 years ago | (#25035665)

What is likely (already) happening is that supercap properties are being combined with conventional batteries. Creating supercap-battery hybrids.

A project doing this showed promising results in tests until the partner handling the patent found out they weren't allowed to collaberate with other battery companies after all. Fools...

Re:How? (2, Informative)

Paradigm_Complex (968558) | about 6 years ago | (#25035691)

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 [wikipedia.org] 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.

Re:How? (2, Informative)

Ihlosi (895663) | about 6 years ago | (#25036037)

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.

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25036237)

"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."

Dude, better check your logs either your brain got a parity error or the driver for your right index finger suffered an exception sometime around 'Wednesday September 17, @03:35AM'.

Were you riding on a bumpy road earlier?

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25035693)

Wouldn't packing it tightly and using a solid dielectric be enough to avoid toasting on bumps? (I just woke up, so I might be missing some common-sense detail.)

Graphene's properties (5, Insightful)

JSchoeck (969798) | about 6 years ago | (#25035991)

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).

It's not just the area that matters here (1)

melted (227442) | about 6 years ago | (#25035711)

It's also the distance between the electrodes. The thinner the dielectric layer, the more charge the capacitor will hold. The problem is then to avoid the electrical breakdown of the dielectric.

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25035719)

Aha! So the new laptop batteries will be football-field-sized bagels with carbon on them?

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25035785)

The carbon isn't really an improvement. I'll stick with cream cheese on football field-sized bagels.

Re:How? (2, Funny)

Anonymous Coward | about 6 years ago | (#25035817)

But you wouldn't even be able to taste the carbon on your football field that way. Seems silly to me.

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25035951)

I'd provide a car analogy, but security won't let me drive mine onto the field to prove the concept.

Re:How? (1)

amirulbahr (1216502) | about 6 years ago | (#25035957)

Now instead of cream cheese it's carbon atoms.

Ok, you lost me there.

Re:How? (1)

Born2bwire (977760) | about 6 years ago | (#25036007)

I'm not sure if I've got this quite right. Let's say I have a car. In this case, I would guess a Ford would best approximate cream cheese. So I need to squash the Ford with a car crusher so thin that it covers an entire car lot? But instead of a cream cheese Ford we're doing it with a carbon Toyota?

Re:How? (1)

codeButcher (223668) | about 6 years ago | (#25036013)

It still depends on the size of the field. Is that Soccer, Rugby or American Football? Aussie Football, Gaelic football? Perhaps harpastum, episkyros, kemari, Shrovetide football? :-)

Re:How? (2, Funny)

NotBornYesterday (1093817) | about 6 years ago | (#25036845)

American football, probably. No reason to cover a soccer or rugby field with cream cheese, that I can think of.

Re:How? (1)

Weirsbaski (585954) | about 6 years ago | (#25036199)

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.

Reminds me of Dilbert-
"Imagine a donut, fired from a cannon at the speed of light while rotating. Time is like that, except without the cannon and the donut."

Re:How? (5, Funny)

Perf (14203) | about 6 years ago | (#25036227)

If you wanted a thin layer of carbon, wouldn't it be easier just to toast the bagel?

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25036275)

Now instead of cream cheese it's carbon atoms.

*energy drink all over keyboard* lol

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25036337)

And if the cheese was green it could be spread on the moon ..... and the moon would look as if it was made of green cheese.

Re:How? (1, Funny)

paul248 (536459) | about 6 years ago | (#25035591)

You should learn about this magical new discovery known as "the third dimension." It lets you make flat things all squiggly and stuff.

Re:How? (1)

gazita123 (589586) | about 6 years ago | (#25035609)

Usually this is accomplished by a "jellyroll" arrangement, where the sheet is rolled up with a dielectric separating film (Mylar, etc.). So, you would possibly coat the Mylar sheet with the Graphene and then roll it.

Re:How? (0)

Anonymous Coward | about 6 years ago | (#25035863)

The dielectric is water (sometime to lower resistance). It can act as a dielectric you apply = 1.25V across it in 2 carbon electrodes.

Currently the electrodes are built with active carbon for its high surface area.

Making available high surface area is one thing, but unless you can LOWER the internal resistance, then it is useless for the end application which is for power storage. Remember that the resistance is sheet resistance and aspect ratio dependent...

Unlike a battery, the discharge voltage follows Q=CV, so you'll need complicated power circuit that can drop the output voltage for part of the discharge curve and boost it for the rest to make better use of the energy storage.

Re:How? (4, Informative)

m.dillon (147925) | about 6 years ago | (#25035629)

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

Re:How? (2, Informative)

KenRH (265139) | about 6 years ago | (#25035645)

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.

Re:How? (3, Funny)

Diamo (1364811) | about 6 years ago | (#25035735)

So why not just use toilet roll as a capacitor?

Re:How? (2, Informative)

Repossessed (1117929) | about 6 years ago | (#25035865)

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.

Re:How? (5, Interesting)

Ihlosi (895663) | about 6 years ago | (#25035913)

So why not just use toilet roll as a capacitor?

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?).

Re:How? (1)

kcelery (410487) | about 6 years ago | (#25036035)

lab exercise one, what happen to a resistor with more current than it can handle.
result: charred resistor and white smoke.

lab exercise two, what happen to capacitor with more AC current than it can handle.
result: a pop corn, sometimes a juicy pop corn.

lab exercise three, .....

Re:How? (1, Funny)

Anonymous Coward | about 6 years ago | (#25036249)

Someone already tried it. Results were crappy.

Re:How? (1)

NotBornYesterday (1093817) | about 6 years ago | (#25036875)

Probably because of the adverse reaction most people would experience when wiping their genitals with electrically charged toilet paper.

Re:How? (1)

Stooshie (993666) | about 6 years ago | (#25036995)

erm, how much graphene has that surface area. If your talking 2,630 square meters of graphene has a surface area of 2,630 square meters then it's not that impressive.

Cost. (1)

Merls the Sneaky (1031058) | about 6 years ago | (#25035535)

More or less than traditional batteries when production is at commercial levels? Will they be prohibitivly expensive to have electric cars using these?

Re:Cost. (0)

Anonymous Coward | about 6 years ago | (#25035583)

the energy / volume (aka energy density) is still horrible in ultracapacitors (below 20% of equivalent lithium batttery). the last time i read up on this (just last week), various manufacturers (namely car companies and laptop/gadget manufacturers) said they wouldn't even consider commercial viability until at least 40%. even then, you're not going to see it in your iphone because the battery on most smartphones already requires nightly charging. it's ridiculous to think that people would have to charge 2x per day or every 60 (or even 100) miles.

Re:Cost. (2, Insightful)

kestasjk (933987) | about 6 years ago | (#25035625)

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.

advantages of batteries (4, Insightful)

loshwomp (468955) | about 6 years ago | (#25035537)

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.

Re:advantages of batteries (1)

RuBLed (995686) | about 6 years ago | (#25035679)

And I could put it on the roof during a hot day to recharge it.

Re:advantages of batteries (5, Insightful)

OldMiner (589872) | about 6 years ago | (#25035801)

I know you're trying to be cleverly ironic here, but you can buy ultracaps today [digikey.com] . The higher power capability, swifter charging, longer life, wider thermal operation range, more flexible packaging, and lower maintenance are already there and have been for years [edn.com] along with the superior environmental characteristics. However, "lighter" isn't true yet, since the energy density of an ultracap is an order of magnitude lower than that for a dry cell [wikipedia.org] . That's why a breakthrough such as in this article is such a big deal.

If grapheme could reliably be utilized to create the sort of energy density posited here, any application requiring large amount of batteries (such as electric cars) would benefit greatly. Unfortunately, since capacitors are more prone than dry cells to losing energy over time due to internal resistance, this won't eliminate the need for dry cells entirely.

Re:advantages of batteries (1)

Woek (161635) | about 6 years ago | (#25036329)

Well put and entirely true of course. That makes me wonder about their claim that ultracapacitors are 'lighter' than batteries. As far as I know, the mass related energy density (J/kg) of capacitors is still lower than batteries, i.e. they are heavier!

Re:advantages of batteries (0)

Anonymous Coward | about 6 years ago | (#25036705)

Additionally, electric double-layer capacitors offer much higher power density than batteries. Power density combines the energy density with the speed that the energy can be drawn out of the "device. Batteries, which are based on the movement of charge carriers in a liquid electrolyte, have relatively slow charge and discharge times. Capacitors, on the other hand, can be charged or discharged at a rate that is typically limited by current heating of the electrodes. So while existing electric double-layer capacitors have energy densities that are perhaps 1/10th that of a conventional battery, their power density is generally ten to one-hundred times as great (see diagram, right).
(Google Ultra Capacitor Wiki)
Batteries are not more energy dense then capacitors.

surface area of a football field (1)

Lord Lode (1290856) | about 6 years ago | (#25035611)

If 1 gram of graphene has the surface area of a football field, what's the surface area of a football field of graphene?

Re:surface area of a football field (2, Funny)

RuBLed (995686) | about 6 years ago | (#25035663)

45 miles per gallon, which I say is not bad...

Re:surface area of a football field (3, Insightful)

Ihlosi (895663) | about 6 years ago | (#25035689)

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 ...

Re:surface area of a football field (1)

Ihlosi (895663) | about 6 years ago | (#25035925)

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 ...

Oh, and before I forget, that's going to be a large number in football fields. Use Rhode Islands instead (or, if the number is still too large, Texas').

Re:surface area of a football field (1)

bakes (87194) | about 6 years ago | (#25036175)

One football field, of course

But how much would that weigh?

Re:surface area of a football field (1)

julesh (229690) | about 6 years ago | (#25036285)

Now, if you were to ask what the surface area of a VW-Beetle-equivalent of graphene is ...

About half the size of Delaware.

Re:surface area of a football field (2, Funny)

tekrat (242117) | about 6 years ago | (#25035723)

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"?

Re:surface area of a football field (0)

Anonymous Coward | about 6 years ago | (#25035841)

And is that "football" or "Soccer"?

No, the question is: is it "Football" or "American Football"?

Re:surface area of a football field (0)

Anonymous Coward | about 6 years ago | (#25035947)

I'm pretty sure the answer is 'football' or 'american football', depending on which of those questions was being asked. Because if it was 'soccer' or 'football', it'd be a football pitch, not a field.

punk teenagers (1, Interesting)

Anonymous Coward | about 6 years ago | (#25035777)

In my day we had to calculate everything as VWs in the Library of Congress.

Re:surface area of a football field (0)

Anonymous Coward | about 6 years ago | (#25035877)

11.

Re:surface area of a football field (1)

plasmacutter (901737) | about 6 years ago | (#25036053)

the answer, of course, is the backstreet boys.

Safety ? (2, Insightful)

CdBee (742846) | about 6 years ago | (#25035729)

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...

Re:Safety ? (5, Interesting)

Genda (560240) | about 6 years ago | (#25035847)

That's one of the serious problems with any exceptionally high density energy storage technology. How do you keep the genie in the bottle, and protect the public from the critically stupid in our society.

There was a very cool design for a car whose power source was a high mass flywheel in a magnetic housing. You go to a power station, and the station would spin your flywheel up to some insane RPM rate. The possibility of using this in a hybrid vehicle meant you could get really excellent energy storage and return, it was very efficient.

The only drawback, was that if the bloody thing ever got out of containment, you had a death dealing juggernaut that would buzz-saw a swatch of destruction through the middle of wherever the now flying flywheel was pointed. Then some bright child imagined such a flywheel driven vehicle on a crowded freeway causing a chain reaction of thousands of other similar vehicle, and suddenly you pretty much have a scenario for mass destruction that looks like front row seats to Armageddon.

Whatever technology you finally pick, you'll need to make it very safe, or decide it's a Darwinian herd thinning tool.

Re:Safety ? (0)

Anonymous Coward | about 6 years ago | (#25036015)

Darwinian herd thinning tool you say... not a bad idea!

When can we expect it being commercialized?

Re:Safety ? (1, Interesting)

Anonymous Coward | about 6 years ago | (#25036309)

How did they plan to fight the angular momentum?

Re:Safety ? (0)

Anonymous Coward | about 6 years ago | (#25036409)

The easiest way would be to mount it laying flat, so to speak.

Re:Safety ? (3, Interesting)

vivian (156520) | about 6 years ago | (#25036489)

Simple - mount it in a gimbal [wikipedia.org]

Re:Safety ? (1)

NoisySplatter (847631) | about 6 years ago | (#25036533)

Forgive me my poor understanding of gyros.
How do you get the power on and off of the flywheel if it's mounted in a gimbal? Wouldn't adding or subtracting energy be a problem then?

Re:Safety ? (1, Interesting)

RegularFry (137639) | about 6 years ago | (#25036613)

The way I'd do it is by having two contra-rotating flywheels, one on top of the other. It doesn't solve all the problems, but it gets rid of the most obvious one.

Re:Safety ? (1)

Profane MuthaFucka (574406) | about 6 years ago | (#25036559)

Make the flywheel out of scotch tape. Without the adhesive. Just wind it tight and spin it. Experiments have been done to show that when it breaks the energy is dissipated safely, but you have to clean up a giant wad of cellphane tape.

Re:Safety ? (2, Interesting)

Ihlosi (895663) | about 6 years ago | (#25035893)

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?

Hate to break it to you, but if you replace the ultracapacitor with a battery of the same volume, or, heaven forbid, the same volume of gasoline, you're looking at even _more_ stored energy, and no one's too worried about that.

Re:Safety ? (2, Interesting)

Kitsune (8349) | about 6 years ago | (#25036145)

Genda may not of quite nailed it on the head in writing but does have a point: capacitors have the ability to discharge a huge amount of their stored energy at once. All the people I know that used to fix TVs have stories of being thrown across their rooms by forgetting to bleed the charges on (non-super-cap) capacitors and letting something short. In comparison, batteries and gasoline even seem have a limit on the amount of discharge they provide in any period... though a comparable example for gasoline might be to finely mist the all the gas into a well oxygenated room and throw in a match. Wheee! ;)

That said, as it's so fast to charge, hopefully it'll become a practical tech at some point. It'd be great to just be able to plop my laptop/phone/whatever on the tray for a few seconds then walk away with a fully charged battery.

Re:Safety ? (4, Informative)

Eivind (15695) | about 6 years ago | (#25036611)

More energy, true, but slower release-rate.

A battery has significant internal resistance, even if you short-circuit it the power-levels are limited. (high, but limited)

A capacitator can recharge significantly faster.

Put differently, the thing may only hold 10% of the energy in a battery. But if that energy is released a hundred times quicker, you're still looking at hell of a bang.

Re:Safety ? (2, Interesting)

mangu (126918) | about 6 years ago | (#25036081)

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 doubt those numbers. Capacitors in valve radios were more like 32uF, and typically work at hundreds of volts. Values like 3200uF are used in low-voltage power supplies, not in valve equipment, unless it's some very specialized equipment from the 1950s with hundreds of valves, perhaps.

But you are right that charged capacitors can be dangerous. I myself once got a strong shock from a capacitor that had been disconnected from a circuit for about ten minutes, after that I learned to discharge any capacitor in a high voltage power supply. An innocent looking yet dangerous equipment is the normal photographic flash. There you can find, typically, a 200uF capacitor charged to 200 volts.

Re:Safety ? (1)

RegularFry (137639) | about 6 years ago | (#25036547)

I see no reference (anywhere) to the likely internal resistance of these posited ultracaps. It's great that you can store all that energy in them, but if it all turns to heat when you try to get it out, it's not much use.

Phone Books (0)

Anonymous Coward | about 6 years ago | (#25035941)

Wow...with a surface area like that.

Imagine if you had two phone books made out of graphene - and interleaved their pages.

You'd, like, never be able to pull 'em apart.

Re:Phone Books (1)

NoisySplatter (847631) | about 6 years ago | (#25036069)

Unless you used two UltraMegaTanks borrowed from the New Tokyo Defense Force.

Memory any one? (1)

diegocn (1109503) | about 6 years ago | (#25036347)

When I saw a capacitor that can charge and discharge rapidly, the first thing came to my mind was actually memory. I wonder how practical is graphene capacitor used as a memory storage cell compare to SRAM or DRAM we have today.

Re:Memory any one? (2, Interesting)

Ihlosi (895663) | about 6 years ago | (#25036385)

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.

Yes but... (1)

mnbjhguyt (449178) | about 6 years ago | (#25036357)

is it american football or european football (=soccer?)

am i the first to make a flux capacitor joke ? (1)

unity100 (970058) | about 6 years ago | (#25036517)

or should i use the delorean to go back to when article was posted ?

reedeeculous as a capacitor plate (1)

Ancient_Hacker (751168) | about 6 years ago | (#25036575)

It's golly-gee wonderful if they can make a one-atom thick graphene sheet. Give them a lollipop.

But in making a capacitor, you need other attributes than just thinness. You need a capacitor plate that can carry current, remain in place in the face of strong electrostatic fields, be compatible with dielectrics, be reliable, and be manufacturable.

A one-atom thick sheet is not going to be able to do any of those things. Capacitor makers have been depositing thin electrodes for 60 years now. They know full well what the limits are. The limits are about four powers of ten higher than these neophytes are talking about.

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