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Charge Your Cellphone In 20 Seconds (Eventually)

timothy posted about a year and a half ago | from the drive-by-juicing dept.

Power 295

New submitter GoJays writes "An 18-year-old from Saratoga, California has won an international science fair for creating an energy storage device that can be fully juiced in 20 to 30 seconds. The fast-charging device is a so-called supercapacitor, a gizmo that can pack a lot of energy into a tiny space, charges quickly and holds its charge for a long time. What's more, it can last for 10,000 charge-recharge cycles, compared with 1,000 cycles for conventional rechargeable batteries, according to the inventor Eesha Khare." This one in particular has been used so far only to power an LED, rather than a phone or laptop, but I hope in a few years near-instant charging of portable electronics will be the norm as supercapacitors grow more common.

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Power for the people (0, Offtopic)

Anonymous Coward | about a year and a half ago | (#43766855)

Very Cool
"It is also flexible, so it can be used in rollup displays and clothing and fabric,"

frosty piss (-1)

Anonymous Coward | about a year and a half ago | (#43766859)

fp

supercapacitors are cool (5, Insightful)

jamesh (87723) | about a year and a half ago | (#43766861)

The one thing I like about supercapacitors (and non-super capacitors) is how quickly they can release all their energy. I can't wait to hold one up to my ear when it's embedded inside a device whose manufacture was outsourced to the lowest bidder!

Re:supercapacitors are cool (4, Insightful)

pmontra (738736) | about a year and a half ago | (#43766895)

Yes, creepy...
Another problem is which wire you need to move all that energy into the capacitor in that little time. This applies both to the wire from the wall to the device and the one from the grid to the house (where I live residential contracts are usually limited to 3 kW). I didn't do the math but assuming it's not a problem for a cellphone it might be a problem for a charging a car fast. In a reverse-car analogy it's like having a 2 Mbit DSL to the Internet. Downloading a movie is going to take a long time a Gigabit home network won't help.

Re:supercapacitors are cool (4, Interesting)

Anonymous Coward | about a year and a half ago | (#43766939)

In a reverse-car analogy it's like having a 2 Mbit DSL to the Internet. Downloading a movie is going to take a long time a Gigabit home network won't help.

We have overland lines a few hundred yards from our house, and there is a gas pipeline running right under the stables. It should be easy to recharge either an electric car or a natural gas powered one in the course of milliseconds.

The problem are the taps. As a result, our AC is quite less dependable than the buzz of the overland lines, and we don't even have gas in the house, instead having to make do with (quite more expensive) oil heating.

Maybe we should go for inductive car charging and park the car under the overland lines.

Re:supercapacitors are cool (5, Interesting)

pv2b (231846) | about a year and a half ago | (#43767153)

To extend the reverse-car analogy, the correct analogy is the use case of wanting to transmit a large movie to a USB stick so you can watch it on your TV. Doesn't matter if you have the best-of-the-best USB stick and USB 3.0 in your computer. The bottleneck is still the internet connection. So what you do is that you set your computer to download that large file while you're out doing whatever it is you're doing all day, and copy it over to your USB stick quickly when you get home. (You could even conceivably automate this process or remote control it from your cell phone.) In this scenario, having USB 3.0 *will* help since it'll cut down on the time on getting the movie from your computer to the USB stick.

Analogously, the way you'd do it for a residential charger, is that you'd have the power grid trickle charging a supercapacitor that you have at your home (ideally under some kind of control from the power company, so that they can manage the load on the electric grid) over the course of a few hours, so that when you need the power, you can just plug it in and almost instantly get your car charged up.

Although while we're on the subject of analogies, a better reverse-car analogy would be that of a flush toilet, slowly building up a reservoir of water to then quickly release it when required.

Re:supercapacitors are cool (-1)

Anonymous Coward | about a year and a half ago | (#43767365)

Heh.

On a good day, I can download a movie torrent faster than I can copy it to a USB drive afterwards.

Of course, that's a 100/100Mb fibre connection from the computer to the 'Net, and this laptop has only USB 2.0, but even so... :)

Re:supercapacitors are cool (0)

Anonymous Coward | about a year and a half ago | (#43767467)

100Mbps is still only 10 megabytes per second. Are you so cheap that your USB 2.0 key can't write at 40 megabytes per second?

Re:supercapacitors are cool (5, Funny)

ifiwereasculptor (1870574) | about a year and a half ago | (#43767437)

I think a better toilet-related analogy for slow intake and fast discharge would be someone at an all-you-can-eat taco buffet.

Re:supercapacitors are cool (0)

Anonymous Coward | about a year and a half ago | (#43767255)

3kW? Where is that? I have 200 amp service and it's used inside the house at 220 volts and 110 volts. At 3kW you couldn't even fully utilize two 15 amp circuits at 110 v.

Re:supercapacitors are cool (1)

Anonymous Coward | about a year and a half ago | (#43767283)

3kW is like boiling water to your morning coffee and making a toast at the same time.

Re:supercapacitors are cool (1)

Zontar The Mindless (9002) | about a year and a half ago | (#43767381)

Dude, the circuit for my home office (originally meant as spare bedroom) is rated 3kW, and in the winter I have to be careful to run the electric heater I keep under my desk at 750 rather than 1250W lest I trip the breaker and thus kill the router.

Maybe you meant 30kW?

Re:supercapacitors are cool (3, Funny)

_xanthus_47 (2612937) | about a year and a half ago | (#43766933)

I beg you! Please be merciful for the sarcasm impaired

Re:supercapacitors are cool (4, Insightful)

nzac (1822298) | about a year and a half ago | (#43767007)

The fuse would blow regardless of the power supply....

You short a battery and it generally explodes as well. The advantage here is with the quick charge time you could get away with storing less energy in your phone.

Re:supercapacitors are cool (2, Informative)

Anonymous Coward | about a year and a half ago | (#43767039)

Drop a spanner on the poles of a truck battery, and the battery does not exactly explode (the poles may get damaged). But molten metal flying around is still not fun. The problem is not the capacitor, the problem is whatever may do the shortcircuiting.

Re:supercapacitors are cool (1)

johnsnails (1715452) | about a year and a half ago | (#43767391)

This exact same thing happened to me :( not fun.

Re:supercapacitors are cool (0)

Anonymous Coward | about a year and a half ago | (#43767041)

You should tell Boeing they need to install fuses in the 777!

Re:supercapacitors are cool (2, Informative)

thegarbz (1787294) | about a year and a half ago | (#43767071)

Sigh! Supercapacitors are inherently stable and generally won't explode unless you actively force them too (i.e. most things explode when you put 1kV up it's arse).
High energy densities and high currents are emitted when shorted and you end up with maybe a spark. Quite a safe spark though given the pathetically small voltages they can store. The same can be said for non-super capacitors too. The only only ones which really let go with a bang are tantalum caps, and even they are quite stable run under their rated voltage.

Sorry to drain the FUD out of your sarcastic post but with caps your biggest risk is electrolyte running down your ear.

Re:supercapacitors are cool (3, Interesting)

rtb61 (674572) | about a year and a half ago | (#43767169)

Even smarter, not one super capacitor but a whole series of them, which discharge into a low capacity rechargeable battery (that high output discharge will actually extend the life of the battery as it would prevent crystalline build up), in sequence to provide smooth delivery of power. The series of small super capacitors can still be charged at high speed and via a more regular rechargeable battery provide smooth delivery of current.

Re:supercapacitors are cool (2)

ultranova (717540) | about a year and a half ago | (#43767171)

High energy densities and high currents are emitted when shorted and you end up with maybe a spark. Quite a safe spark though given the pathetically small voltages they can store.

Voltage is irrelevant. If a short releases the stored energy, all of it is converted into heat, since it has nowhere else to go. If stored energy is significant, and is released in a short enough time, this results in an explosion.

So, the safety-relevant questions are: how much energy can a capacitor store, and how much currency can it supply?

why do people sigh (0)

decora (1710862) | about a year and a half ago | (#43767265)

the idea of moving large amounts of energy between two storage reservoirs is inherently more dangerous than the slow charge systems we use now.

by the way the name FUD got a lot of popularity regarding Java.

fear - im afraid java will be bought by some shit hole corpoarte master --- true

uncertainty - im uncertain if sun will even be a company in a few years. -- true

doubt -- i dbout anyone will want to deal with version incompatabilities and all the other junk to use java on web pages, especially when javascript and webgl are doing so well -- true

Re:supercapacitors are cool (1)

jamesh (87723) | about a year and a half ago | (#43767273)

Maybe the super capacitor won't explode, but you still have to consider the amount of energy they can hold, and what the result might be if all that energy discharges instantly into the phone if some fault arises. I bet it could generate a loud enough pop to damage your hearing.

Re:supercapacitors are cool (2)

Eivind (15695) | about a year and a half ago | (#43767301)

If they are to be useful, they need to store substantial amounts of energy. A Samsung SIV has a 2600 mAh at 3.7V -- anything that's substantially less for the same size ain't gonna cut it, because even with fast charging, you aren't gonna want to charge ten times a day.

10 Watt-hours isn't a HUGE energy-amount, but it's not trivial either. Charging in 20 seconds means supplying the device with about 2 kilowatts of power. A catastrophic short-circuit discharge that drains the supercap in a second while melting large parts of the phone delivers about 40 kilowatts of heat over a period of one second.

This ain't a "small harmless spark".

Then again, supercaps cannot -actually- replace batteries, because their energy-storage sucks even more than batteries do, and batteries are already plenty sucky. (a litre of diesel is 10 Kwh....)

Re:supercapacitors are cool (2)

fazig (2909523) | about a year and a half ago | (#43767361)

Capacitors much like batteries don't store "voltage" they store electrical charge (basically electrons), ampere seconds.
Regular cell phone batteries have a charge of about 2Ah, assuming this super-capacitor will have a similar charge and remembering that a capacitor can be discharged at least as fast as it can be charged, in 20 seconds or less, this could create an average current of 360 ampere, give or take a few ampere. Given the nature of the current flow when discharging a capacitor the current will be twice as high in the first few seconds of discharging at about at least 700 ampere.

And that's no laughing matter anymore.

This article [batteryuniversity.com] says that' their cell voltage is between 2.3 and 2.75V. Lets assume a value in the middle of 2.5V.
-> Capacity: C=Q/U=(7200As)/(2.5V)=2800F (!!!)
-> Electrical Energy: E=0.5*C*U=.5*2800F*(2.5V)=1400(As/V)*6.25V=8750AVs=8750J

Granted, these numbers are quite speculative because I lack the exact specifications, but it should give you a rough estimate of the numbers we're dealing with here.

Re:supercapacitors are cool (0)

Anonymous Coward | about a year and a half ago | (#43767131)

I assume we'll mostly use arrays of small capacitors that discharge in sequence, rather than just wiring the output directly across a grenade.

Re:supercapacitors are cool (1)

Anonymous Coward | about a year and a half ago | (#43767289)

we'll mostly use arrays of small capacitors that discharge in sequence, rather than just wiring the output directly across a grenade.

Each cell could be connected via a diode and resistor/fuse to the power rail. You can quickly charge via the diode, but the discharge should take at least minutes otherwise the resistor blows the circuit. If you phonically damage one capacitor it will violently release a fraction of the total energy of the package, which would be designed to prevent a chain reaction.

little light on the science details. (2)

gl4ss (559668) | about a year and a half ago | (#43766873)

did she have some new angle to the tech?

you can buy capacitor based battery replacements for cars.

Re:little light on the science details. (4, Insightful)

jamesh (87723) | about a year and a half ago | (#43766881)

did she have some new angle to the tech?

you can buy capacitor based battery replacements for cars.

The only new thing in there was "holds its charge for a long time", which I thought was the only real barrier to supercapacitors replacing batteries. I suspect that "a long time" isn't quite correct for useful values of "long".

Safety is obviously a concern too, but industry doesn't really need to worry about that until the first cell phone blows someone's ear off or laptop blows someone's crotch apart.

Re:little light on the science details. (5, Informative)

msauve (701917) | about a year and a half ago | (#43766957)

"did she have some new angle to the tech?"

Yes. The article was terrible. She almost tripled the energy density of supercapacitors. From her paper [usc.edu] :

Methods/Materials
To improve supercapacitor energy density, I designed, synthesized, and characterized a novel core-shell nanorod electrode with hydrogenated TiO2 (H-TiO2) core and polyaniline shell. H-TiO2 acts as the double layer electrostatic core. Good conductivity of H-TiO2 combined with the high pseudocapacitance of polyaniline results in significantly higher overall capacitance and energy density while retaining good power density and cycle life. This new electrode was fabricated into a flexible solid-state device to light an LED to test it in a practical application.

Results
Structural and electrochemical properties of the new electrode were evaluated. It demonstrated high capacitance of 203.3 mF/cm2 (238.5 F/g) compared to the next best alternative supercapacitor in previous research of 80 F/g, due to the design of the core-shell structure. This resulted in excellent energy density of 20.1 Wh/kg, comparable to batteries, while maintaining a high power density of 20540 W/kg. It also demonstrated a much higher cycle life compared to batteries, with a low 32.5% capacitance loss over 10,000 cycles at a high scan rate of 200 mV/s.

Re:little light on the science details. (2)

Intrepid imaginaut (1970940) | about a year and a half ago | (#43766973)

Mod parent up. What I want to know is where did she get access to technology that could operate on the "nanoscale" as well as fabrication equipment, this stuff isn't exactly commonplace or cheap. Although it would be great if it was in every school.

Re:little light on the science details. (2)

muon-catalyzed (2483394) | about a year and a half ago | (#43767129)

Nanorod electrode is nice, but these UCLA guys has already took it to the next level by designing an electrode made of graphene (video footage).
http://www.youtube.com/watch?v=RVUf7-tTLXo [youtube.com]

Re:little light on the science details. (5, Informative)

msauve (701917) | about a year and a half ago | (#43766997)

Correcting myself: She claims to have increased mass specific capacitance by almost 3. I'm not sure how her volume specific capacitance compares - I'd think that would be more important for cell phone use.

Mass energy density of commercial supercaps is 3-5 Wh/kg, but 85 has been seen in the lab, according to Wikipedia. Her's is 20.1, which may be significant if it can be commercialized.

Some more numbers (5, Informative)

Attila the Bun (952109) | about a year and a half ago | (#43767429)

Interesting numbers. Just to compare, here's the energy densities of lithium-polymer batteries and super-capacitors, taking the values for best easily-available components I could find.

LiPo: 168 W.h/kg, 370 W.h/l

Super-cap: 5.1 W.h/kg, 6.6 W.h/l (I'm being slightly generous to the capacitor here, by counting the energy to discharge it to zero volts. In practice that last bit of energy will not be usable.)

The volumetric figures are most critical for phones, and in those terms batteries are 56x better than super-capacitors. So an improvement of 3x is interesting, but there's a lot more work to do.

Serious shit (0)

Anonymous Coward | about a year and a half ago | (#43767001)

I am surprised nobody has been locked away for providing a minor (I presume she did some work before turning 18) with access to chemicals and/or processors. If you crank out this sort of shit at eighteen, you had some seriously supportive tutors who decided not to follow every rule of the book.

Re:little light on the science details. (4, Interesting)

amaurea (2900163) | about a year and a half ago | (#43767081)

Hmm, I don't understand these numbers. 20 Wh/kg works out to 72 kJ/kg, which is much less than the 1.08 MJ/kg Wikipedia quotes for supercapacitors. On the other hand the article on supercapacitors claims 15 Wh/kg to 30 Wh/kg as the typical range of commercially available values, so perhaps the other number unrepresentative. Anyway, these numbers would place the 20 Wh/kg result in the article squarely inside the range of commercially available supercapacitors when it comes to energy density. This is also about 10 times lower energy density than rechargable lithium batteries. So not exactly something you want in your mobile phone.

Re:little light on the science details. (4, Funny)

stephanruby (542433) | about a year and a half ago | (#43766977)

did she have some new angle to the tech?

Yes, she did. She used a "led" as a demo device for her super battery.

Basically, a led is the equivalent a cell phone without a screen, without an antenna, without sensors, without memory (except for one bit), without a gps, without a speaker, without a microphone, without an amplifier, without a cpu, without a gpu, etc. Plus, it's a great device for simulating the power consumption of an actual cell phone.

A "led" is a also a great device to give your kids instead of a cell phone. It doesn't have a great range, may be just a couple of meters. And it needs to be in the constant line of sight of the person your kid is communicating with. But barring those two little constraints, it's a good tool for your kid to learn morse code (provided that "led" is the only piece of electronics/toy your kid has access to), it works great at night, it comes with uncapped/unlimited data, and it doesn't come with an expensive bill no matter how much your kids do texting with it.

Re:little light on the science details. (5, Funny)

horza (87255) | about a year and a half ago | (#43767005)

The problem is that Ubuntu touch doesn't support the 1x1 screen resolution. We need the inventor to release the specs so a Mir graphics driver can be written. I've tried an alpha version and personally find the scroll bars tricky, but then that's always been a problem with Unity. This is the problem with Canonical trying to get one OS to work every device.

Phillip.

Re:little light on the science details. (1)

mikael (484) | about a year and a half ago | (#43767079)

You could get one of those gamers backlight keyboards - they have a single RGB color value that can be programmed so all the keys can be any one of 16 million colors. Some even have an itty-bitty 320x240 LCD screen that can be accessed via USB.

Re:little light on the science details. (1)

Dunbal (464142) | about a year and a half ago | (#43767249)

You don't need a touch screen all you have to do is push hard enough to separate the contacts.

ubuntu is my god. (1)

decora (1710862) | about a year and a half ago | (#43767275)

how dare you. HOW DARE

Re:little light on the science details. (0)

Anonymous Coward | about a year and a half ago | (#43767175)

someone got jealous

Re:little light on the science details. (0)

Anonymous Coward | about a year and a half ago | (#43767317)

At 5-10 mA, the power draw of LED is comparable to that of an idle phone, that powers only the receive circuitry.

Re:little light on the science details. (1)

ebno-10db (1459097) | about a year and a half ago | (#43767439)

At 5-10 mA, the power draw of LED is comparable to that of an idle phone, that powers only the receive circuitry.

Which is ideal if you're trying to demonstrate that the self-leakage of the capacitor is not a serious impediment, since the self-leakage is a greater issue when the cell phone's power consumption is less.

Re: little light on the science details. (0)

Anonymous Coward | about a year and a half ago | (#43767195)

The new angle was she was the most brown and the most female.

Gizmo? (3, Insightful)

cyber-vandal (148830) | about a year and a half ago | (#43766875)

Sometimes I really hate "technology" reporting.

Re:Gizmo? (4, Insightful)

queazocotal (915608) | about a year and a half ago | (#43766899)

Quite.
Supercapacitors have been around for a couple of decades, getting a lot cheaper recently.
Tens, or hundreds of millions of dollars have been spent on their development.
At the moment, they lag _considerably_ behind cellphone batteries in terms of energy storage per unit volume, and cost.

Sure, you can make a supercapacitor battery for your phone and it will charge in 10s. But it may only run the phone for several minutes.

The above article gives absolutely no information whatsoever that indicates the student in question has overcome this barrier, which is absolutely key.
Otherwise, this is just a 'student invents flying car' - when the proof given is a balloon tied to a toy car.

A very cynical person might say that the reason for the award was in the photo.

I am not saying that the student has not done work beyond simply sticking a $7 capacitor in a box with an LED, but that is all the article can lead one to guess.

Re:Gizmo? (2)

queazocotal (915608) | about a year and a half ago | (#43766905)

On closer reading, I find that it does indicate she fabricated the capacitor - which is noteworthy, and an achievement for someone of her age - but unless she has achieved actual breakthroughs in the field, this is again not nearly as newsworthy as the headline suggests.

Re:Gizmo? (5, Informative)

thegarbz (1787294) | about a year and a half ago | (#43767083)

but unless she has achieved actual breakthroughs in the field, this is again not nearly as newsworthy as the headline suggests.

She has. [usc.edu] The only problem here is that the news itself is dumbed down to the point of being utterly pointless.

Science reporting at it's finest.

when i was 18 my main accomplishment (1)

decora (1710862) | about a year and a half ago | (#43767277)

was ruining about 20 pairs of bedsheets with cum stains, and finishing X-Wing vs Tie Fighter

Re:when i was 18 my main accomplishment (1)

Anonymous Coward | about a year and a half ago | (#43767417)

When I was 18, we didn't have bedsheets--er, X-Thing--er, nevermind, just get off my lawn already.

Re:Gizmo? (3, Informative)

BasilBrush (643681) | about a year and a half ago | (#43767299)

A very cynical person might say that the reason for the award was in the photo.

They might, but since she has constructed a novel supercapacitor, they'd be wrong. Don't let the "it's political correctness gone mad" people win.

Re:Gizmo? (1)

Atzanteol (99067) | about a year and a half ago | (#43767385)

But will it power my kajigger's and whatnots?

"My cellphone battery always dies," (0)

Anonymous Coward | about a year and a half ago | (#43766887)

Somebody buy the poor girl a Nokia [nokia.com] phone, the newer ones run for a month between charges.

Too much current (5, Informative)

ebcdic (39948) | about a year and a half ago | (#43766897)

My phone battery has a capacity of 2.1Ah. To charge it in 20 seconds would require a current of 380 Amps. What kind of charger could safely supply that?

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43766925)

A 12V battery for a UPS or small vehicle could handle that. So the charger will be a lot bigger.

Re:Too much current (1)

goranb (209371) | about a year and a half ago | (#43767009)

and now try to imagine a plug that could handle 380A :)

Re:Too much current (1)

wmac1 (2478314) | about a year and a half ago | (#43767323)

So the charger will be a lot bigger.

Not necessarily. If the charger uses higher voltages than 12V then the size and the current do not need to be that large.

Re:Too much current (4, Insightful)

Anonymous Coward | about a year and a half ago | (#43766983)

Your phone battery has a capacity of about 3.3V*2.1Ah=7Wh. To charge it in 20s takes 7Wh/(20/3600)h=1260W, which is about the power of a hairdryer or a microwave oven, for a short time. There may be some technological hurdles to implementing that, but safety-wise this kind of power is not a big deal in the household.

Re:Too much current (1)

jpatters (883) | about a year and a half ago | (#43767025)

You would need a much thicker cable than the ordinary cell phone charger cable, and the phone itself would have to be significantly thicker than an iPhone to accept the plug, unless you accept that you can only re-charge the battery (at that speed) when it is removed from the phone and put in some sort of fast charger. (Good luck getting Apple to adopt that idea.)

Re:Too much current (1)

Anonymous Coward | about a year and a half ago | (#43767073)

Hey, why not? It's an extra accessory. You can trickle-charge it for a couple of hours the traditional way, or you can buy the iCharger that will get the job done in twenty seconds. They'd eat that shit up, and so would their customers.

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767139)

Actually they could use the backside of the phone for the contacts of the internal battery, that means the contacts have a large area to run power through.
In fact you could use the metal apple logo as one of the high power contacts, maybe the outside rim as the second high power contact.

Re:Too much current (2)

BasilBrush (643681) | about a year and a half ago | (#43767313)

Apple would ask the question, "if we used a Lightning connector, with a reasonable cable, how many minutes can we do it in?"

20s is great for people who want to brag, but far from necessary.

Re:Too much current (1)

N3TW4LK3R (841526) | about a year and a half ago | (#43767327)

Actually, the GP is right about 380 amps. To charge a 2.1Ah battery, you need 2.1/3600*20 amps at the battery's voltage.

You're also right in saying that your household power supply can easily take it at high voltage, but you must take into account the conversion to low voltage too.

The charging equipment would simply be huge and the cable and plug would be ridiculously impractical at 380A.

You'd need something in this order of magnitude :)
http://i01.i.aliimg.com/wsphoto/v0/575796945/GENUINE-ANDERSON-SB-350A-600V-POWER-CONNECTOR-WITH-2-0-AGW-CONTACTS.jpg [aliimg.com]

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767371)

My point is that the connection doesn't have to work at such a low voltage. Even at just 30V, the current is reduced to 40A. With the low power draw of the cellphone electronics (or when you use the capacitor to charge a LiPo battery), stepping the voltage down inside the phone isn't a problem.

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767419)

There's no reason to stick with such a low battery voltage. A DC-DC converter is required anyway in the phone, capacitors have a sqrt() discharge graph not mostly linear like batteries. And converters are more efficient at higher voltages. Taking electric safety intro consideration (dropping the phone in the bathtub) something like 20V top voltage is practical. A good phone battery has about 1400mAh @ 3.3V = 5Wh, you can deliver that in 30 seconds at 600W, or 30A@20V.

30 Amps is not that high, especially considering the charging unit will monitor the voltage drop across the power connection and modulate the charge to prevent overheating. A poor connection or cable will charge slower without overheating. That's unlike say a 30A wall socket that must be over-engineered for the worst case oxidation and poor mechanical pressure. Bottom line, you can easily achieve a charging time of minutes with connectors not very different than the ones we use today.

Re:Too much current (2)

msauve (701917) | about a year and a half ago | (#43767063)

I can picture a charger which itself has a supercap. Charger tops up local supercap over a few hours, then transfers that energy to the cell phone battery over a short period. As far as current, you couldn't do it with reasonable gauge wires, but you could have some sort of large flat contact arrangement where the battery is pressed against the charger, or inserted in a slot. 380A is fusing current for ~6.5 mm^2 copper (about a 9 gauge wire), and you could certainly fit much larger contacts than that on a battery.

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767267)

you could also swap the two batteries :)

Re: Too much current (1)

Anonymous Coward | about a year and a half ago | (#43767069)

"Charge in 20 seconds" is not a requirement. Charging in, say, five minutes would still be a lot better than five hours.

Re: Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767259)

I was thinking exactly this. 5 minutes drops the power required to 84W, which is completely feasible. It would be AWESOME to charge in 5 minutes and then have all day power. As it is, my phone stays plugged in more than half the day so I don't run out of juice.

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767149)

yes but that is not why batteries take so long to charge the fact of the matter is your typical lipo battery requires a set voltage and can only take so many amps before thermal run away causes a gas release of the cells leading to critical failure.

Batteries have a certain level of resistance to regaining lost electrons applying more volts or amps causes heat and most battery formulations and devices can only take so much before the chemical reactions change and fire, explosions or out put of hydrogen gas occurs. What a super capacitor really does is lowers that resistance so that the electricity can flow into the containing space quicker. Even now the reason we don't use this technology is the size of storage is not enough to power a phone for a minute let alone 12 hours. Also capacitors are not good at retaining the voltage they store what they like to do is dump it all at once. What has been achieved with "super capacitors" is slowing it down so we can take only a set amount of amps out of them. I think advancements in battery tech will continue to out pace this technology as there have been several new ideas recently on how to increase storage make flexible and speed charge rates of conventional batteries. I am looking forward to several new formulations not based on lithium that are likely closer to seeing market presence than this technology.

Re:Too much current (1)

Twinbee (767046) | about a year and a half ago | (#43767261)

Would it be possible to allow higher voltage (on the part of the phone and/or charger) to mitigate or get around that problem?

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767303)

Use two, switch them daily, won't take more than 20 seconds. Ford invented pipelining to hide latency a century ago.

Re:Too much current (0)

Anonymous Coward | about a year and a half ago | (#43767353)

Christ, this gets modded +5 these days? Ah is not a measure of energy, it's a measure of charge (Coulombs). You need to multiply that number by volts to get energy (P=IV, E=Pt).

OP made a mistake, sure, and I don't want to be harsh on him/her - we all do it. But how many people up modded this? Ridiculous - this is basic physics people.

For reference: 2.1Ah at 3.3V is about 25 kJ. Charging at 110 V in 20 seconds would require on the order of 11 A. Not an insignificant charge, but certainly something your home circuits can handle.

Intrigued... (4, Insightful)

mathfeel (937008) | about a year and a half ago | (#43766901)

But what did she do? What is the underlying science/technology? The NBC report got nothing. Click-through to Intel's website for the competition did not immediately yield any more information, except an inspirational paragraph about her:

With the rapid adoption of portable electronics, Eesha Khare, 18, of Saratoga, California, recognized the crucial need for energy-efficient storage devices. She developed a tiny device that fits inside cell phone batteries, allowing them to fully charge within 20-30 seconds. Eesha’s invention also has potential applications for car batteries.

Will be doing some more Googling, but seriously, a link to the lab in which she worked or article/abstract published would be nice. Surely these are gifted kids, but I can't help but think the reporter really doesn't understand what she's done to write any thing more than a press release.

Re:Intrigued... (-1, Troll)

Anonymous Coward | about a year and a half ago | (#43766949)

"But what did she do?"

She has a vagina near some wires. That's enough for unlimited praise these days.

Re:Intrigued... (0)

Anonymous Coward | about a year and a half ago | (#43766987)

You don't understand! The point of this is for *Intel* and only Intel to make money!
It will not be published, until a patent was made for *Intel*, and until she was raped in all holes and ripped off, then billed for that, sued, and then some.

No earlier will any of this ever be released.

Charge in 5 seconds (1)

hcs_$reboot (1536101) | about a year and a half ago | (#43766907)

...change the battery with a freshly charged one (if you're not a lucky iPhone owner).

Re:Charge in 5 seconds (1)

mikael (484) | about a year and a half ago | (#43767107)

In some European cities, street merchants and hotels would offer an exchange service for flat cellphone batteries vs. charged batteries. Rather than you leaving your phone lying around in your room plugged into the mains (and risk being stolen), you could go to reception or the street and get a
swap.

Re:Charge in 5 seconds (1)

msauve (701917) | about a year and a half ago | (#43767167)

5 seconds? What kind of phone do you have?

On mine (HTC Rezound), replacing the battery involves removing the back cover, maybe 15 seconds or so if I'm quick. Then, it takes a couple of minutes to boot up, since it was powered off.

Terrible article (1)

Alioth (221270) | about a year and a half ago | (#43766911)

Is there a link to some article not in the mainstream media? The article has no details at all. Did she use an off-the-shelf super capacitor? What circuits did she make (one characteristic of a capacitor is the voltage immediately goes down as soon as you take charge from it, unlike a Li-Ion battery which maintains a more or less constant voltage through most of its charge), and how efficient is the voltage regulation? What about the energy density of the device? All supercaps I know of have a very small fraction of the energy density of a lithium ion battery. To replace a Li-Ion you need similar energy density or you get a massive phone.

Forgotten (4, Insightful)

Alioth (221270) | about a year and a half ago | (#43766927)

What a lot of these articles forget is the current requirements to charge something fast. Just because something can be charged fast doesn't mean you can do it.

Let's take a typical laptop battery of 70 watt hours. To charge it in one hour, you need a 70W power supply (more or less). Now let's charge that same battery - if we can - in 30 seconds, or 120th of the time. You'll need an 8.4kW charger to do that, which is going to be much larger and heavier than the laptop. In Britain where the mains electricity is 240 volts, you're going to need 35 amps to do that (typical household circuit is 13 amps, high power circuits for example ovens and tumble dryers are 30A). In the United States you'll need 70 amps.

OK, so you can charge slower (but still much faster than a conventional battery) but it's still going to require a large (heavy) power supply for your laptop if you want to make the charging speed significantly faster than current lithium ion batteries. You're either going to wind up lugging around a lot of extra weight with your portable machine, or you're going to need two chargers (more expense). The thing is, the times when you really wish you can charge a battery quickly are always times you're travelling and so won't have the large heavy charger with you!

Re:Forgotten (1)

jones_supa (887896) | about a year and a half ago | (#43767021)

Now let's charge that same battery - if we can - in 30 seconds, or 120th of the time. You'll need an 8.4kW charger to do that, which is going to be much larger and heavier than the laptop.

Not necessarily. If you only need to run it about 30 seconds at full blast, it doesn't have to have the size of a PSU designed to constantly deliver 8.4kW.

Re:Forgotten (1)

gshegosh (1587463) | about a year and a half ago | (#43767033)

This is all true, but I can imagine that high-current charger and battery connectors get standardized and everyone has one charger for all their devices at home and at the office. Perhaps even vending-machines that charge batteries? If it only takes 10 or 20 seconds, why not? Heck, if it only takes a few seconds, I can have a shared charger in the building, so me and my neighbours use only one.

Re:Forgotten (2)

msauve (701917) | about a year and a half ago | (#43767109)

"You'll need an 8.4kW charger"

No, you don't. You're making the mistake of applying existing paradigms to new technologies.

You can use a much lower power charger to charge a local supercap (inside the charger) over a longer time, then when you charge the "battery," you simply transfer that energy.

Re:Forgotten (1)

djmurdoch (306849) | about a year and a half ago | (#43767445)

Transferring 70 watt-hours in 30 seconds is going to need high voltages and/or high currents, both of which are difficult to handle safely. You need heavy cables to carry 70 amps, and you need good insulation to handle 120 volts.

Re:Forgotten (1)

thegarbz (1787294) | about a year and a half ago | (#43767123)

Except the target application in this case is phones which represents about 1/10th of the powerload. Suddenly you're at 840W to achieve a 30 second charge time.

But hey why go overkill? We the consumer are used to waiting for hours. Why don't we worry about small targets with smaller benefits first? Let's just charge my phone in 5 minutes. 84 watts now is less than most of my household appliances and I would be incredibly happy if we could do that.

Re:Forgotten (2)

vadim_t (324782) | about a year and a half ago | (#43767229)

It's useful even if you can't do it in 30 seconds.

How about a 1000W charger? That's about a tea kettle, perfectly doable in domestic conditions. Laptop charged in 5 minutes while you have your breakfast.

Sure, the charger will be a bit large, but you can offer both high and low power chargers. High power for the people who have a need for the laptop to be charged quickly. Low power for something you can travel with.

For cell phones it gets even easier, since quite a few can be charged from the 5W USB provides. I'd love a say, 20W phone charger. Still not huge, but capable of bringing a phone into usable state fairly quickly, while I have my lunch at the airport.

Re:Forgotten (1)

silas_moeckel (234313) | about a year and a half ago | (#43767331)

Just split the difference and put a super cap in the supply and trickle charge it.

Re:Forgotten (1)

ledow (319597) | about a year and a half ago | (#43767235)

That's right.

So basically, all these fancy energy-saving methods we've been implementing lately have been wiped out by things that are EVEN WORSE for the grid than what we had.

Electric cars, supercapacitors, etc. all add to PEAK usage. Between 5:30 and 6:00 everyone is going to be putting their 8KW charger on, even if only for a second, and raising peak time usage (which means that even more capacity has to be brought online - sometimes for hours before and after - to cope with demand and we'll be "even more" idle throughout the rest of the day).

And, shockingly, the only plants that can really handle those are the old-fashioned, always-on, slow-to-ramp-up-and-down, coal, oil, gas and nuclear plants. Or HUGE inefficiencies from renewables.

I just find it ironic that at the time we're pushing for low power, variable, "always on" supplies, we're pushing for gadgets that need high peak load, or high load for a LONG time generally.

FTFA: (2)

lobiusmoop (305328) | about a year and a half ago | (#43766931)

"supercapacitor, a gizmo that can pack a lot of energy into a tiny space, charges quickly and holds its charge for a long time"

Ah, Not really, no [wikipedia.org] . Supercapacitor=1Mj/KG, pretty weak sauce relatively speaking.

Personally, I'm, holding out for a 'Doug Stanhope' phone with an ethanol fuel cell than 'runs on booze'.

Re:FTFA: (1)

Anonymous Coward | about a year and a half ago | (#43767103)

Thing is, she redesigned the capacitor from the ground-up, using fab processes that are unavailable to the general public, and managed to triple the energy density of the best supercapacitors. That's the tiny detail the author failed to pass on.

Re:FTFA: (0)

Anonymous Coward | about a year and a half ago | (#43767119)

Supercapacitor=1Mj/KG

Really? One mega-(imaginary unit) per kelvin times (universal gravitational constant)?

I think you may have meant 1 MJ/kg.

Already there (2)

yacc143 (975862) | about a year and a half ago | (#43766943)

The rough version is there, it's called (quite missleadingly) a second battery plus a charger that can charge batteries externally. Been using that setup for years now and it can charge a phone in seconds, as long the phone has a changeable battery.

Guess companies might be able to fine tune it, e.g. make batteries easier to eject and insert, plus add a capacitor (a normal one, that keeps the phone live for say 30s), and you've got instant charging, today.

Why stop at cellphones? (1)

houghi (78078) | about a year and a half ago | (#43766959)

A 20 second loading of cellphones is not really a must have. It is a nice to have. With a phone you will be for longer then 20 seconds to reload it (e.g. at your desk, when you sleep)

Where such load times would come in handy is with electronic cars. That way you can drive cross country and do refills at the same speed as you do now.

The reason that supercapacitors are not already (1)

mark_reh (2015546) | about a year and a half ago | (#43767305)

powering our cell phones is that in order to get the super high capacitance the "plates" of the capacitor must be microscopically close together which limits the voltage at which they can operate to typically 2.5V. The next problem is that you can't use all the energy stored because you need a DC input converter circuit to regulate (and step up) the ever falling voltage as the capacitor discharges and those circuits require some minimal level of input, maybe a few hundred millivolts, below which they cease to function. While the total energy storage capacity of the capacitor is great, you can't use all of it, so if you compare the usable energy storage of a supercapacitor to a similar sized Li-Ion battery, the battery wins.

Batteries, on the other hand, provide adequate current via a chemical reaction that maintains a more or less constant, higher voltage output until the battery is almost completely discharged, at which point the voltage drops precipitously. This works well with the circuits in a cell phone.

If this student managed to make a supercapacitor that operates at 5V or higher in the same physical volume as current technolofy 2.5V parts, or solved some other problem related to the technology- maybe a voltage converter circuit that efficiently delivers a usable current from the capacitor at 20 mV input, then she made quite a breakthrough.

I think fuel cells are a more promising technology for cell phone battery replacement than supercapacitors. You can have your "instant" charge by squirting in some butane or whatever fuel it uses, but then I'm not sure if they can pack the same energy density as li-ion cells. The other potential game changer for phones, computers, and cars is lithium-air batteries which have much higher energy densities that li-ion cells.

Replaceable battery (1)

Misagon (1135) | about a year and a half ago | (#43767321)

Just have two batteries. On on charge and one in the phone. It will also take 20 seconds to change the battery.

What the... (0)

Anonymous Coward | about a year and a half ago | (#43767409)

So how is it that an eighteen year old girl with no science degree comes up with what PHDed scientist have been looking for for decades? Foot dragging to prevent the federal grants from disappearing after the invention? Or incompetence maybe? The curse of embracing the God hating theory of evolution? We might need to turn to our high school students for answers from now on. It would certainly be cheaper.

Capacitors have problems, and will never rule. (3, Informative)

aurizon (122550) | about a year and a half ago | (#43767423)

One problem with capacitors is the charge is stored a lot like water in a tank. As you use water the water level drops, in any capacitor, as you use it the voltage drops.
The governing equation is Q = 0.5 *C*V*V.

A single cell (in a battery of cells) is composed of two materials of different chemical states and they produce a constant voltage until one of the chemical states is depleted. Charging reverses this, again at a constant voltage. The charge and discharge voltages in a theoretically perfect cell are ~~ the same, in a real cell, resistance caused voltage drops and departures from irreversibility lead to differences in the charge discharge voltage. You must charge with a high voltage than you get on discharge.

A second problem, is the fact that a bulk material changes state in a cell, this inherently stores more charge than a capacitor, which is a surface layer of added charge. It is true that since the capacitor involves no change of state, that the life is more or less infinite, and because it is a monolayer of charge, you can charge and discharge at speeds limited only by the current limits of the wires.

The net result is the energy density of the best capacitors is barely as good as the worst batteries.
Battery graphs here http://tinyurl.com/autjb7l [tinyurl.com]
Capacitor graphs here http://tinyurl.com/byqbdje [tinyurl.com]
Direct comparisons here http://tinyurl.com/b9zwcdw [tinyurl.com]

As long as you design a downstream voltage regulator to use the declining voltage to power your circuit at its required constant voltage, then ultracaps will find a niche in many pieces of equipment from Cars(as a peak acceleration source) to tiny items as the sole power

Super capacitors? Seriously? (0)

Anonymous Coward | about a year and a half ago | (#43767447)

Anyone remember the 1980's? Remember how the CMOS RAM on your PC's motherboard used to be powered by super capacitors before CR20xx batteries became cheap enough? Super capacitors have been around a loooong time.
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