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Charge Your Cellphone In 20 Seconds (Eventually)
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.
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!
did she have some new angle to the tech?
you can buy capacitor based battery replacements for cars.
world was created 5 seconds before this post as it is.
Sometimes I really hate "technology" reporting.
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?
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.
The only possible interpretation of any research whatever in the 'social sciences' is: some do, some don't
...change the battery with a freshly charged one (if you're not a lucky iPhone owner).
Slashdot, fix the reply notifications... You won't get away with it...
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.
Oolite: Elite-like game. For Mac, Linux and Windows
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!
Oolite: Elite-like game. For Mac, Linux and Windows
"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. 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'.
"I bless every day that I continue to live, for every day is pure profit."
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.
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.
Don't fight for your country, if your country does not fight for you.
Ten minutes to charge and off the shelf:
http://www.toshiba.com/ind/product_display.jsp?id1=821
* Carthago Delenda Est *
how dare you. HOW DARE
was ruining about 20 pairs of bedsheets with cum stains, and finishing X-Wing vs Tie Fighter
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.
Just have two batteries. On on charge and one in the phone. It will also take 20 seconds to change the battery.
"We mustn't be caught by surprise by our own advancing technology" -- Aldous Huxley
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
Capacitor graphs here http://tinyurl.com/byqbdje
Direct comparisons here http://tinyurl.com/b9zwcdw
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
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.
Forgot to mention self-discharge rates: 0.007 C/day for LiPo batteries, and 0.08 C/day for super-caps (12x greater)
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?
Don't jump to conclusions or buy too much into the article's hype. She made a capacitor using AFAIK a novel chemical/construction technique, and it works well according to some measures. That's a very impressive feat for a high school student, and she certainly deserves a full ride to her Ph.D. at the university of her choosing. It does not mean it's practical, which could be for any number of reasons. Maybe it's too fragile to be practical, whatever. Hopefully she'll be one of those people looking for a practical solution, or maybe she's smart enough to get a law degree or an MBA and make some money instead of rubbing nickels together as a post-doc.
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.
Computers have been around an even longer time. Would you rather use a current model or one from the 80's? Tech improves even if the names of the devices don't.
No, that's what happens when you do it at a university lab, not at home while being clueless to boot. That's all.
A successful API design takes a mixture of software design and pedagogy.
SuperCaps where not invented or even perfected by some 18 year old guy. They have been used as energy storage for a long time now, in newer times e.g. in professional-level SSDs to allow a clean data flush on power failure. They are completely irrelevant as energy source for cellphones as, despite their impressive capacities in the full-Farad range, they cannot store enough energy. The primary limiter is that they have low maximum voltages. And cellphones have some minimal energy requirements that cannot be reduced for the RF part.
I should also remind you that a modern low-current LED can be pretty bright at something like 1mA, and typically less than 5mW. That little will not get a cellphone to do anything.
Another clueless article from somebody that did not bother to find out any actual facts.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
There were no affordable supercaps with leakage current low enough in the 1980's your memory is playing tricks on you. The standard means used was NiCad button-cell accumulators.
You are right about the age of supercaps though.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Easy solution would be to have multiple smaller ones - I don't know enough electronics to know the advantages/disadvantages of having them in this situation in parrallel or in series, In this way, you might be able to "pop" charge your battery in very small increments. That is - have multiple small supercaps, that you quick charge, and have them hooked up to your battery (or even be the batery).
..........FULL STOP.
You could go the other way to solve this problem: make the batts/caps smaller and able to hold *less* charge.
Phone needs charge; Phone spends most of it's time in my jacket; Phone receives pwr from jacket pocket.
Jacket needs charge; Jacket spends most of it's time on the coat hook. Wire coat hooks to the mains electricity supply.
Planet needs charge; Planet spends most of it's time orbiting a star; Wire planet directly to sun;
Sun needs charge: Someone else's problem.
I'm not usually one to get petty about the summaries, but, "Charge your Cell Phone in 20 Seconds ..(eventually)".. eventually? That's just trolling at this point, if it's 3 years or more away. Not to mention the inherent dangers of a super capacitor.
Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
This is a 12th grade high school student competing in the science fair (and applying to colleges, taking AP classes and tests, etc.) I think she has more things to do than submit articles to refereed journals which would take a year to publish anyway. the abstract from the science fair is what you get today. You *could* have gone to the fairs in Los Angeles (CSSF) or Phoenix (ISEF) and grilled her all you like for details.
I would expect the journal articles in a year or so.. She has plenty of time this summer to write them.
Complain all you like, but it's the news media who are more interested in whether Beyonce is pregnant, whether Jodie will get the death penalty, or whether some kid will be a number 1 draft pick, than in incredibly talented high school students doing PhD level work.
Anyone can understand pregnancy, murder, and throwing a ball: Understanding how supercapacitors work, and what might improve them is well beyond most reporters; heck, looking through the comments above, I'd say it's beyond most slashdotters.
You are correct. Batteries were used for that in the 80's, not capacitors.
Most of this problem could be resolved if manufacturers made phones with slide-in, slide-out battery packs. One is charging while one is in use. Very simple system, been around for decades. No high-tech solutions needed.
Of course then they might lose the advantage of monitoring everywhere you go ... or being able to lock you in as a customer for *very* expensive battery replacements ... the only "reasons" I can see for doing the obvious thing of making a phone like a transistor radio or like a freaking flashlight.
"You must try to forget all you have learned. You must begin to dream." -- Sherwood Anderson
"Eventually" is a long time (approx 120 years at today's timescale expansion rates) and you can bet that by then the whole problem of adding energy to devices that need it will have been overcome by new developments.
that i cant jerk off 5 times a day like i used to. so writing comments on slashdot.. well, its almost the same thing.
Indeed. I like to amuse me with occasionally reading these stories from 3-5 years back. They basically never pan out.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Ordinary RAM is superior to flash memory in most applications.
Imagine a solid-state storage device that was essentially a flash device with a largish (GBs) capacitor-backed-up non-write-through RAM cache, with the cache only "writing through" when certain conditions existed, such as power loss.
You would only need a few seconds of juice on the capacitor and a smart onboard SSD controller to effectively make "wearout due to writes" a non-issue for most SSD applications.
Bonus points - I/O will almost always be at the faster RAM speed not the speed of the persistent storage chips (subject to limits imposed by the SATA or other communications interface, of course).
Heck, for "cheap" bulk storage skip the solid-state non-volatile stuff and just have a capacitor+ large RAM cache on a traditional spinning piece of metal. Hey, which is cheaper, a 4GB-RAM backed 750GB solid-state device or a 4GB-RAM-backed 750GB 2.5" drive?
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
The article is brief on facts but i would bet my money she has just repeated the graphene super capacitor experiment done by and explained in detail by these guys https://www.youtube.com/watch?v=_oEFwyoWKXo all you need is a light scribe dvd player some grpahite oxide and a dielectric.
Rocket Surgeon.
Can Tesla use this tech in their cars ?
The video references the issue with fast charging: Fast discharging.
People tend to forget that high quantities of stored energy have an inherent danger. Laptops catching fire because of lithium-ion battery failures are usually the only hazard that people tend to remember. To truly have a consumer safe device you want something that can be charged quickly but the maximum discharge rate is closer to a conventional battery.
The point is that when you exceed a certain speed of energy release the device starts resembling a bomb more then a battery. A wrench dropped across both posts of a car battery is spectacular enough in a very scary way (even before the battery actually explodes.) (And don't try this! An explosion can spray acid a LONG way.) A device that can discharge almost instantly is even more destructive. We obviously need to be able to store energy for so many different reasons but the method needs to remain safe even when handled in a completely negligent manner... like a consumer device.
What? Our government wasted billions of dollars on this kind of research and an 18 year old kid solved the problem? OMFG!! The Oil Companies will be out of business in months, and the progressive utopian unicorn fantasy of renewable energy will come true! Nobody will have to work, or pay taxes, or do anything other than party and fornicate. Yippeee!!
Oh wait, it's just a salacious headline designed to get my attention.... with no basis in reality.
Thanks Slashdot. Betcha some nut job argues with me this week that the electric car with the batteries that recharge in 30 seconds has already been invented, and reminds me what a horrible, terrible person I am for driving a full sized pickup truck.
Murphy was an optimist
Agreed, probably longer.
The electric car in 1908 had a range of about 40 miles, and took 6-8 hours to charge. Back then a lot of folks thought all cars would be electric.
Fast forward one hundred years and the electric car has a range of about 45 miles, takes 4 hours to charge. Today, a lot of folks want all cars to be electric.
Do the math...
Murphy was an optimist