Scientists Create Battery That Charges In Seconds and Lasts For Days (telegraph.co.uk)

An anonymous reader quotes a report from The Telegraph: A new type of battery that lasts for days with only a few seconds' charge has been created by researchers at the University of Central Florida. The high-powered battery is packed with supercapacitors that can store a large amount of energy. It looks like a thin piece of flexible metal that is about the size of a finger nail and could be used in phones, electric vehicles and wearables, according to the researchers. As well as storing a lot of energy rapidly, the small battery can be recharged more than 30,000 times. Normal lithium-ion batteries begin to tire within a few hundred charges. They typically last between 300 to 500 full charge and drain cycles before dropping to 70 per cent of their original capacity. To date supercapacitors weren't used to make batteries as they'd have to be much larger than those currently available. But the Florida researchers have overcome this hurdle by making their supercapacitors with tiny wires that are a nanometer thick. Coated with a high energy shell, the core of the wires is highly conductive to allow for super fast charging. The battery isn't yet ready to be used in consumer devices, the researchers said, but it shows a significant step forward in a tired technology.

Comments

I'm going to make a prediction

[Anonymous Coward]

This technology will be in shops within the year.

Re: I'm going to make a prediction

[ArchieBunker]

Those predictions are always so dumb. Buy it and license out the patent to everyone else. But then again this will be another one of those dead end claims like 3d holographic storage and cold fusion.

Re: I'm going to make a prediction

[Anonymous Coward]

Because combining the word "big" and the name of any industry automatically means EVIL.

Re: I'm going to make a prediction

[Anonymous Coward]

Did you even read the "story"? The author is clearly lying through her teeth when she says:

A new type of battery that lasts for days with only a few seconds' charge has been created by researchers at the University of Central Florida.

The high-powered battery is packed with supercapacitors that can store a large amount of energy. It looks like a thin piece of flexible metal that is about the size of a finger nail and could be used in phones, electric vehicles and wearables, according to the researchers.

As well as storing a lot of energy rapidly, the small battery can be recharged more than 30,000 times.

So how is a "thin piece of flexible metal that is about the size of a finger nail" too large? What is the problem other than it's bullshit?

They've been beating this dead horse for YEARS. Where is the end product? Why isn't it available?

Re: I'm going to make a prediction

[alexgieg]

Where is the end product? Why isn't it available?

Because it costs several billion dollars to create the whole infrastructure needed to make any of these things at an industrial scale, while the infrastructure for Li-Ion one is already in place and can be cheaply adapted to new improvements on the already proven technology. Besides, Li-Ion has the "advantage" of forced obsolescence, requiring user to purchase new ones for their devices every few years.

Down the line it might be worth it to invest in these new technologies, particularly if some new technology appears that requires such massive power densities and speeds and there's huge demand for it, as was the case with electric cars and the new battery tech they require. Right now however the economics of scale, coupled with the potential lower long term profits, don't favor investing in it.

Re:I'm going to make a prediction

[newcastlejon]

My prediction is that this is a fluff piece and the "breakthrough" is complete bullshit.

Of course, it's being reported in the Telegraph.

Re: I'm going to make a prediction

[ChoGGi]

I've got a Yankee screwdriver, works a treat for and nothing to charge.

Re: I'm going to make a prediction

[eric_harris_76]

Not to worry. Practical fusion power -- cold or regular -- is just around the corner, about 20 to 25 years away. Still. Again. Always.

Re: I'm going to make a prediction

[originalmouse]

"Big Porno"

Finally.....

[vatin]

No more worries about non replaceable batteries!!!

So, how often does it explode?

[bistromath007]

I'm not an expert, but I'm pretty sure that whenever energy is both very dense and very accessible, you've made an explosive. Existing battery technology is already going that direction. At what point will I need to register my phone as a destructive device under the NFA?

Re:So, how often does it explode?

[SumDog]

https://xkcd.com/651/

Re:So, how often does it explode?

[Black Parrot]

At what point will I need to register my phone as a destructive device under the NFA?

Samsung will register it for you before they ship it.

Re:So, how often does it explode?

[CaptainDork]

Electronics guy here, and I was thinking along the same lines.

Capacitors are two plates, very close together, separated by an insulator.

We attach power up to the two plates and a static charge occurs between the two.

After we remove the power source the capacitor retains the static charge and would do so forever if it weren't for decay due to leakage across the insulator.

The "capacity" of a capacitor is directly proportional to the surface area of the two plates.

The voltage it can hold is defined by the arc-through point of the insulator quality and distance between the plates.

Sounds like they have all that figured out.

--

The advance in battery consumption has bottomed not been on the battery and breakthroughs on the efficiency of the device(s) that needs the battery power have pretty much topped out, as well.

This method could be a game-changer, but I wonder about factors that would degrade the integrity of the system, especially the distance between the two plates (punctures, blunt force, flexibility) and the shelf life of the insulators.

Those factors have always been a concern with capacitors.

Re:So, how often does it explode?

[ArylAkamov]

This method could be a game-changer, but I wonder about factors that would degrade the integrity of the system, especially the distance between the two plates (punctures, blunt force, flexibility) and the shelf life of the insulators.

Hobbyist reporting in, and this is exactly what I was curious about. That better be a damn good insulator, otherwise we are in for a whole new ballgame of Note 7s.

I very much want better battery technology, but that also invites some very destructive failure modes.

Re:So, how often does it explode?

[evilviper]

I'm pretty sure that whenever energy is both very dense and very accessible, you've made an explosive. Existing battery technology is already going that direction.

That's nonsense.

NiMH and LiFePo batteries are at least 2/3rds as power-dense as Li-Ion by volume, but are EXTREMELY stable and safe... Moreso than lower density Alkaline batteries.

Meanwhile, the least-dense battery technology being used is lead-acid, as found in your card battery, and they have a bad habit of exploding, too. Probably much more than Li-Ion batteries.

Re: So, how often does it explode?

[Anonymous Coward]

With tech that can charge in seconds, id probably guess it results in changes to device expectations. Something like cell phones that hold less total power, but can be charged wirelessly in a few seconds every 4 hours or something. Basically more frequent yet quicker charges.

Re:So, how often does it explode?

[Anonymous Coward]

The advance in battery consumption has bottomed not been on the battery and breakthroughs on the efficiency of the device(s) that needs the battery power have pretty much topped out, as well.

Lieutenant Colonel Korn, take that sentence out and shoot it.

Re:So, how often does it explode?

[thinkwaitfast]

First year physics... q = Integral[current, t]

F = 1/(4piepsilon0) q^2/r^2

IIRC from a homework problem 20 years ago, if you had 2 pennies with a 1% charge differential between them, there would be enough force to life the WTC. (I said it was a long time ago).

Re:So, how often does it explode?

[ShooterNeo]

Couldn't you wire it with a current limiting diode so a short won't lead to an explosion?

Re:So, how often does it explode?

[Anonymous Coward]

The GP missed the other part, that capacitance is inversely proportional to separation of the two plates, and a lot of the advances in higher density capacitors has come from making the plates separated by smaller and smaller distances. You don't have some large voltage between the plates, with a lot of the higher capacity ones being quite low voltage of a couple volts max without putting multiples plates in series (the electric field across the small insulator still ends up being large...). But the neat thing with really thin insulators that are often the result of chemical reactions, is they can sometimes self repair faults. Electrolytics have done this for some time, and they often have much higher voltages across the insulator that could quickly drive a lot of current even with not that low of a resistance fault (it is a bit disconcerting to sit next to a fridge size rack of caps that sound like the tinging of a cooling engine block as minor faults self repair the first time you charge them up or condition them after some odd situation).

Re:So, how often does it explode?

[Anonymous Coward]

Belay that order ..... death's too good for it... Cardinal, get the comfy chair!!

Re:So, how often does it explode?

[PingPongBoy]

This method could be a game-changer, but I wonder about factors that would degrade the integrity of the system, especially the distance between the two plates (punctures, blunt force, flexibility) and the shelf life of the insulators.

Hobbyist reporting in, and this is exactly what I was curious about. That better be a damn good insulator, otherwise we are in for a whole new ballgame of Note 7s.

I very much want better battery technology, but that also invites some very destructive failure modes.

In the light that capacitors are being used, the way to alleviate the battery's distress is to build a sensor that detects the battery wants to dump core, and also build a device that responds, when the detector goes into the red, by shooting two prongs ... no, just a minute, that's how to make a taser.

Re:So, how often does it explode?

[AmiMoJo]

Actually batteries are already about as good as we can reasonably charge them in most instances.

In electric vehicles we are already getting close to the limits. Tesla charges at 120kW, but actually they pair up bays so it's 120kW shared between two. If one car is already pulling 110kW, the other only gets 10kW. Going higher is difficult because you need an even bigger connection to the electricity grid, and a charger capable of handling more heat.

Maybe you have a 3kW electric heater in your home. If the Tesla charger is 97% efficient it has to dissipate 3kW of heat. The car also has to dissipate considerable heat as the batteries warm up, which is mostly due to the chemical reaction so does represent an area where improvements can be made.

Even for your phone, based on the form factor, the thickness of the USB cable wiring, the need for a buck converter... If you had a capacitor that could charge in a minute the USB cable would melt and the buck converter would melt the phone. You would need to dump 650W into it, so even at 99% efficiency (impossible) you would need to dissipate 65W. Maybe you have seen what a 65W CPU cooler looks like, a large metal heatsink with a fan attached to it.

Re:So, how often does it explode?

[AmiMoJo]

It's not really accurate to compare a battery to a hand grenade though, even if they contain similar amounts of energy. The grenade can release it all in a fraction of a second, while the battery, even if shorted, will take several orders of magnitude longer. Could start a nasty fire but you certainly couldn't throw one and expect it to detonate.

Re:So, how often does it explode?

[AmiMoJo]

*90%. My bad, 99% would only be 6.5W, still problematic in such a small space.

90% is a very high target for a charging circuit... Typical buck regulators that operate in the required range with small inductors (to keep the phone thin) will manage around 80% with careful design.

Re:So, how often does it explode?

[tomxor]

Electronics noob here :P The failure modes of normal super-capacitors appears to be quite different to the smouldering ceramic or exploding electrolytic based capacitors. From wikipedia on normal super-caps:

...theoretically supercapacitors have no true polarity and catastrophic failure does not normally occur. However reverse-charging a supercapacitor lowers its capacity...

So assuming nothing vaporises when multiple tiny shorts occur from blunt force, puncture or over voltage etc... then i guess the question is what else happens after all those shorts? would it heat up a lot to the point of melting or causing an external fire? would it try to discharge suddenly and cause electrocution?

Re: So, how often does it explode?

[CCarrot]

Explosive? Not necessarily. It is a capacitor, not a battery. So no energy-rich chemicals. Short a capacitor, and it may deliver enough energy to melt whatever you short it with. Or melt the wiring. No need for the cap itself to explode though.

Really? That was one of the primary amusements in our freshman labs, listening for the first 'pop' of a capacitor wired backwards, and they certainly weren't packed with C4...

Re:So, how often does it explode?

[silentcoder]

Depends what you throw it at. A jar of nitroglycerine maybe ?

Re:So, how often does it explode?

[silentcoder]

Actually, this would likely be a LOT safer than the exploding batteries, exactly because a capacitor is a much simpler device. Critically - it needs no chemically volatile liquids. Batteries are filled with highly reactive chemicals - they have to be to store energy in the form of lose ions. Lose ions only exist if the chemical is highly reactive.
Highly reactive == potentially explosive.

But a capacity is made of solid, non-moving parts - I actually can't see a scenario where it could explode. A huge charge with a short could possibly cause a great deal of heat, and some major sparks which could set OTHER things on fire, but I can't see a scenario where a capacitor would burn . There's no reason to put any flammable material whatsoever in one.

Maybe somebody with more knowledge than me can show that these types contain some highly reactive/flammable materials and that this is important to their operation but I wouldn't bet on.

Re:So, how often does it explode?

[CaptainDork]

YouTube has many examples of exploding super capacitors, but the devices in this article are too new for us to know how they react to abuse.

Re:So, how often does it explode?

[wagnerrp]

Arc flash is a serious thing, especially when the device is in your pocket.

Re: So, how often does it explode?

[wagnerrp]

A capacitor's voltage is directly related to the square root of charge remaining. Start out at 12V, and by the time your voltage dropped to the 3.7V of a standard LiPo battery, you're down below 10% charge remaining.

Re:So, how often does it explode?

[silentcoder]

Sure, but it's not an explosion.

Re:So, how often does it explode?

[Anonymous Coward]

Capacitors have internal resistance, and different kinds of caps can have wildly different internal resistance values. Electrolytics can discharge a lot faster than a battery, but still have a sizable internal resistance and can actually overheat if you put too much ripple current through one. Supercaps tend to have higher resistance than electrolytics because they use such small conductors to pack in as much as possible into a small unit. Plus some supercaps use a hybrid chemistry + capacitance storage method that results in something much closer to a battery in terms of internal resistance.

If you actually wanted to discharge a cap as fast as possible, you have to buy rather expensive caps that have low resistance and low inductance, and they have rather crappy energy density compared to most other capacitors.

Re:So, how often does it explode?

[wagnerrp]

It's not?

https://www.youtube.com/watch?...

Re: So, how often does it explode?

[undefinedreference]

This has been my experience with both lithium batteries and supercaps. In fact, supercaps are worse as they can discharge more quickly and don't need to wait on slow chemical reactions.

Supercap explosions are very frightening and could be very dangerous.

Re: So, how often does it explode?

[silentcoder]

An explosion is defined as a rapid energetic gaseous expansion. Usually due to a high energy chemical reaction but disturbing a superheated liquid would count too. Arc flash is... not that. Well maybe if its energetic enough to plasmafy the air but I doubt there is any reason to put that much energy in your pocket.

Re:So, how often does it explode?

[CanadianMacFan]

Just the once.

Re:So, how often does it explode?

[aXis100]

Super/Ultra capacitors are not so simple, and share things in common with batteries.

Their total capacitance comes though a combination of
1) Double layer Capacitance - separation of charge in a Helmholtz double layer between the plate surface and the liquid electrolyte, and
2) Pseudocapacitance - electrochemical storage by redox reactions at the electrode surface. This is very battery like.

https://en.wikipedia.org/wiki/...

Re: So, how often does it explode?

[wagnerrp]

From the video...

It creates a pressure wave, called an arc blast, that can reach thousands of pounds per square inch. Enough to knock someone off a ladder, rupture an ear drum, or collapse a lung.

That sure sounds like an explosion to me, far more violent than rather slow conflagration you see from the runaway chemical reaction in a li-ion cell. You did see it blow the head off that mannequin, didn't you?

Re:So, how often does it explode?

[CaptainDork]

Capacitors are not like batteries.

They are batteries.

They are rechargeable batteries.

The math and physics for capacitors and batteries, from outside the devices, are the same.

Capacitors, however, typically have charge/discharge rates measured in fractions of seconds.

Often, it's in microseconds.

Batteries have been, until now, much, much slower at both.

Re: So, how often does it explode?

[silentcoder]

The word 'explosion' literally implies something that grows bigger - the common phrase 'blow up' is actually pretty key to what is, or is not, an explosion. Your definition would mean implosions are also explosions !

And yes, I am being pedantic about terminology since my entire point is that the risk of explosions is far more limited. I never said there can't be other risks or they couldn't be even worse, I am open to that suggestion - but that's another problem and requires different solutions to address.
Explosions create unique and specific issues that make them dangerous. Very few people have ever been killed by an explosion per se. It takes a MASSIVE explosion for the shockware to actually injure people. The shockwave from a hand-grenade is practically harmless even if you're on top of it. May break a few ribs. But that rapid-expansion bit means explosions have shrapnel, and that is the much bigger risk. Most people who die in explosions are killed by shrapnel. An arc-flash doesn't have shrapnel.
Sure it could burn you - but it isn't going to sever your arteries.

Re: So, how often does it explode?

[wagnerrp]

The word 'explosion' literally implies something that grows bigger

The electric arc heats the air around it into a plasma. That plasma expands rapidly, resulting in an explosion.

It takes a MASSIVE explosion for the shockware to actually injure people.

Injuries like ruptured eardrums and collapsed lungs...

But that rapid-expansion bit means explosions have shrapnel, and that is the much bigger risk. Most people who die in explosions are killed by shrapnel. An arc-flash doesn't have shrapnel.

Well the explosion tends to blow apart whatever equipment just failed, producing shrapnel. Seriously, did you even watch the video?

Re:So, how often does it explode?

[evilviper]

the only time they explode is when a charger is connected in reverse.

That's completely baseless. A lead-acid battery, operating normally, can explode at any time. Just ask NASA:

On May 17th, 2010 at approximately 10:00 am, the start-up battery on Generator #1 (not due to start-up) exploded for no apparent reason. [...] when one or more cells have a high concentration of hydrogen gas because the vent cap was plugged or defective and did not release the gas effectively an unsafe condition is created. In addition, when electrolyte levels fall below the top of the plates, a low resistive bridge can form at the top of the plates and when current starts to flow, it can cause an arc or spark in one of the cells to intensify that condition. This combination of events ignites the gas, blows the battery case cover off and spatters electrolyte with potentially injuring unaware personnel and to further damage associated equipment.
http://llis.nasa.gov/lesson/28...

There's untold tomes of more info on the problem, if you'll set aside your ignorance and do some actual research for yourself.

Two issues that need to be addressed

[mykepredko]

One: What is the capacity per unit volume? This isn't mentioned in TFAs. I would think that creating batteries with an order of magnitude (or three) more capacity should be higher priority. Why should we have cell phones that work for days when they should work for months on a charge or cars that only go a couple of hundred miles when they should be able to go thousands of miles on a single charge?

Two: If it can be charged very quickly, it can be discharged very quickly. People were up in arms when three Teslas caught and Samsung phones caught fire. What will be the reaction when devices have batteries that can give up all their charge basically instantly which means literally thousands of Amperes of current.

I suspect that there are applications in which these batteries will be perfectly suited for - but the typicaly ones like phones, cars, etc. will not be in that list.

Re:Two issues that need to be addressed

[Harlequin80]

Electric powered toys will be a huge winner if you can have half decent capacity and a high discharge. Common racing style quad copters will happily draw 130amp and could easily draw more. The limiting factor is definitely the batteries. You draw 100amp from a 1300mah battery and the batteries don't last long.....

Current battery tech for quadcopters gives you batteries that are large and heavy for any given capacity. That is the only way to be able to draw the current.

Re:Two issues that need to be addressed

[mark-t]

Two: If it can be charged very quickly, it can be discharged very quickly.

Sort of... but you can mitigate this to limit it to cases where you connect a third party device that is explicitly designed to extract the stored power from it at said rate. Such devices would be not any more difficult to detect than electronic explosives already are currently. The device itself containing the fast-charging battery could easily contain mechanisms that does not allow the battery to discharge faster than a certain speed for the electronics within, and if this mechanism is hard-wired as circuitry instead of using software or firmware to control it, then there is no way that an end user could making modifications to the device or its firmware that would cause it to exceed that rate.

Re:Two issues that need to be addressed

[mark-t]

Actually, now that I think about it, you could even prevent it from being extracted by a third party device at a high rate by just adding a single diode to the charging circuit. The diode doesn't limit the rate, but it does restrict the direction that charge can flow. If the other side of the storage is hooked up to discharge circuitry that expressly limits the rate at which charge can be tapped from the storage system, then there is no possible way that you could get it to discharge any faster than the hardware was explicitly designed to do.

Re:Two issues that need to be addressed

[Razed By TV]

Increased capacity makes battery explosions even more of an issue than increased discharge rate. A battery that lasts 100 times as long will release 100 times as much energy during a catastrophic failure.

Re:Two issues that need to be addressed

[mark-t]

if it were integrated into the battery, all that would reasonably do is break the entire circuit so it doesn't discharge at all

Re:Two issues that need to be addressed

[Art Challenor]

Ultracapacitors are the holy grail of electrical storage. Cheap materials, many cycles, very rapid charging, etc. etc. The energy density, last time I checked a couple of years ago was on a par with Lead Acid - so fairly heavy and large to get the energy you need. I assume that has, and will continue to improve. If they've reached the density of Lithium-Ion then that's some significant progress. It's a technology to watch, it already has application - typically regen braking in an electric or electric assist vehicle, you can dump a LOT of energy into the ultracaps very quickly and so recapture more of the braking energy, but it's not going to be in your phone any time soon.

Re:Two issues that need to be addressed

[thinkwaitfast]

Nowhere close to lead acid. Energy densities is an order of magnitude lower. Numbers haven't changed in a hundred years

Ultracapacitor: 5-8 Wh/kg and 7 to 10Wh/liter

Lead Acid Battery: 33–42 Wh/kg 60–110 Wh/L

https://en.wikipedia.org/wiki/...

https://en.wikipedia.org/wiki/...

Re: Two issues that need to be addressed

[mark-t]

Sure, but then since two conductive plates are touching there is not enough resistance to the current flow to produce any heat. The charge on the capacitor would be neutralized almost instantly.

Re: Two issues that need to be addressed

[Anonymous Coward]

That energy gets turned into heat one way or another very quickly. There is a certain amount of energy stored in a charged cap, and it doesn't just disappear if you can short the cap with small enough resistance.

(Energy dissipated in resistance will be proportional V^2/R*t, but discharge time goes like RC, so your energy dissipation is proportional to V^2*C... just like the energy in the cap, and energy is conserved yet again)

Re:Two issues that need to be addressed

[Anonymous Coward]

Your info seems out of date by a couple years, considering at my work place we use ~10-11 Wh/dm3 supercaps that are more on the economy side of things and not special order, higher performance options. Research units can range anywhere from 10-100 Wh/kg, and it comes down to finding new manufacturing processes to make those kinds of designs economical, not any fundamental limit.

Numbers haven't changed in a hundred years

Hybrid capacitors didn't exist until the late 60s, and weren't commercialized until later... so the numbers have changed a lot, from zero to current values. They've also been changing over the last 5-10 years, and a lot of it now comes down to pricing and mass production of newer designs.

Re:Two issues that need to be addressed

[CCarrot]

Electric powered toys will be a huge winner if you can have half decent capacity and a high discharge. Common racing style quad copters will happily draw 130amp and could easily draw more. The limiting factor is definitely the batteries. You draw 100amp from a 1300mah battery and the batteries don't last long.....

Current battery tech for quadcopters gives you batteries that are large and heavy for any given capacity. That is the only way to be able to draw the current.

Yep. Approximately 47 seconds, to be precise. 36 seconds at 130A.

That can't be the steady-state draw, or those quadcoptors would barely be able to take off...and what the heck gauge wiring are these things using, if they're seeing that even as a peak? I sure hope it's #2 or better, or battery capacity could be the least of your worries...

Re:Two issues that need to be addressed

[silentcoder]

This actually sounds perfect for powering vapes.

Re:Two issues that need to be addressed

[MooseTick]

"Why should we have cell phones that work for days when they should work for months on a charge or cars that only go a couple of hundred miles when they should be able to go thousands of miles on a single charge?"

You are confusing "should" with "I'd like to have". If we're going that route, then cell phones should have a charge the life of the phone. Cars should have a charge that will go 200k or the life of the car.

Re:Two issues that need to be addressed

[DarkVader]

We can do that. The nuclear battery is a thing, they used to be used in pacemakers. For a car, a small reactor could conceivably power the car for its entire lifespan.

Re:Two issues that need to be addressed

[Harlequin80]

No that is max throttle draw. My freestyle quad will burst pull 100 amp at full throttle, 4 x emax 2205 2300kv motors. They will generate a combined thrust of about 4.8kg on a quad that weighs in at about 520g including battery.

On a 1300mah battery I get about 2.5 to 3 minutes before the battery is empty.

My racing quad though will pull 120 amp+ at full throttle (I don't know exactly as that is the peak of the current sensor I use). I get under 2 minutes on a 1300mah battery in a race. It produces just under 6kg of thrust at full throttle and weighs in at 440g inc battery.

Re:Two issues that need to be addressed

[Harlequin80]

Oh and I use 12awg from the batteries and 16 from the PDB to the ESCs and 18 for the ESC to the motors. Average wire length though is very very short with the longest being the main battery lead at about 40mm.

I also run 4 cell batteries giving me 16.8v on a fully charged battery. You do see 5 & 6 cell batteries but rarely at racing comps, more at drone top speed comps.

yay math

[Anonymous Coward]

A quick search tells me a phone battery typically has a capacity of something like 1500 mAh, so "charge your mobile phone in a few seconds and you wouldn't need to charge it again for over a week" sounds like something on the order of adding 5000 mAh in 30 seconds.

That would mean a current of 600 amps, assuming 100% efficiency. For reference, USB 3.0 has a max of 0.9 amps, Lightning is a little over 2, a refrigerator draws 6 amps, and your household circuit breaker will trip at 15 amps.

Re:yay math

[ClickOnThis]

This. Mod parent up. I was going to post something similar.

Re:yay math

[Waffle Iron]

Without giving the voltage, those numbers are pretty meaningless. Power = Volts * Amps

Lightning has a huge power at 2A because it's millions of volts.

A high-end microprocessor can draw about 100A, but only at a little over 1 volt.

Your circuit breaker will trip at 15A, but at 120V. That's 1800W. If this capacitor is only charged to about 1.5 V like a typical battery, the 600A would only be 900W.

Thus, you could easily charge it from a standard outlet. It would require a beefy power supply similar to those in large servers, though. I think that most people would opt for a cheaper power supply that could still charge their phone in a minute or two.

Re:yay math

[sl149q]

And think of the electrical service you would need to order to charge your EV in (to be similar to gas) say 2-3 minutes.

This says 4.5 megawatts to get down to 15 minutes and involves intermediate storage. Scary stuff!

http://www.computerworld.com/a...

Re:yay math

[thinkwaitfast]

Me too...http://www.wolframalpha.com/input/?i=5%2F.008333

Re:yay math

[Anonymous Coward]

Never tried it, but I suspect that if you hooked up that "household circuit breaker" in series with, say, a car battery at 12V, you could draw about 180 watts of power before it tripped. It's the current through the breaker that matters, not the voltage.

If you used a switching power supply, or even an old fashioned transformer, you can put the full 1700 watts into a low voltage device with 90+% efficiency... or do you still think everything is linear power supplies and a 1A @ 5V charger just drops 110 V down to 5 V with resistance and wastes 105 W of power?

I have an induction crucible heater that outputs about kiloamp into a single turn load, yet runs off of a standard 15 A wall circuit, because with rather simple electronics, it is about the power you can pull, not the current limit at a given voltage.

Re:yay math

[thegarbz]

For reference, USB 3.0 has a max of 0.9 amps, Lightning is a little over 2, a refrigerator draws 6 amps,

By the time this comes to the market we'll be at USB 7.4 anyway.

and your household circuit breaker will trip at 15 amps

WTF? Who wired up your house?

Anyway your assumption is stupid. You mention milliamps, hours, and no talk of voltage. So let's fix your math:

5000mAh in 30 seconds is 600A. Since you made assumptions about it being a mobile phone I will too, 5V. This is 3000W of power.

In a typical 230V house that is 13.04A. Easily delivered by the 18A outlets and the 35A circuit breakers typical for a house in Europe.
Things get a bit more interesting in the USA but really even you guys are capable of providing 3000W. And now that the physics are more realistic let's not forget storage. There's nothing here at all that assumes you will be pulling the charge continuously from the wall instead of say trickle charging an intermediate powersupply.

If you want to criticize this device don't look at the wall, but instead look into the device itself. It is relatively easy to provide a really large amount of power to the device, but I would be far more interested in how they can get this power over the circuit board traces and into the battery.

Re:yay math

[blindseer]

That's enough power to get you 400A at the 4V required to charge a standard phone battery even after accounting for conversion loss.

How large of a conductor would the wire have to be to safely carry 400 amps? According to the National Electrical Code it would be something like an inch in diameter.

There's some serious practical limits on the sizes of conductors for handheld devices. Something that can carry 400 amps of current, with feed and return lines, insulation, safety ground, etc. to make a cable would be the size of a fire hose. The connector would have to be even larger.

Even if we assume we are using this technology for something like electric cars, where such large connectors might be much more practical, there are limits to the voltage. The prongs on an electrical plug are insulated by air. To keep the prongs from arcing continuously from excessive voltage the breakdown voltage of air cannot be exceeded along with a considerable safety factor.

A battery that charges in seconds and last for days is simply impractical unless one is talking about very low voltages and power consumption.

Re:yay math

[blindseer]

That's an interesting claim, that we'd simply charge our cars with 10kV supplies. Protecting the end user is only one of the worries. At those voltages, especially with direct current, arcing is a real hazard. At 10kV the conductors in air would have to be at least 4 inches apart to keep from arcing, and that's with little to no extra safety factor. I simply cannot imagine a connector carrying that kind of voltage being something that any regulatory agency would allow to be handled like we handle gasoline pumps now. We're talking "wouldn't touch that with a ten foot pole" kind of stuff here.

Even if we assume the connector to the car, with 10kV @ 100A, is something that could be considered practical there is still the matter of what happens inside the car. To maintain this size of conductor and still be made of cheap aluminum or copper the voltages would have to remain in the kV range inside the car, that's not going to happen. If stepped down to something in the hundreds of volts the conductors get very large or very hot. If some exotic material is used that has a lower resistance and/or can safely handle temperatures that would melt aluminum then the car gets real expensive.

So, take your pick. Is this car going to run at arc inducing voltages? Will it run at molten aluminum temperatures? Will it cost a fortune? I guess that there is another option, make it large enough to carry the weight of the conductors, to dissipate the heat safely, be made of cheap and common materials, and operate at reasonably safe voltages.

There is a reason electric drive trains are really popular for things like trains, forklifts, and such, heavy and slow is something of an advantage there. Not so great for passenger vehicles.

I'm afraid we will be stuck with electric cars that need many hours to charge.

Re:yay math

[blindseer]

Do you realize that a 330 amp cable would have to be larger than a garden hose? While you are out this Black Friday at Best Buy shopping for Christmas gifts go wander over to the kitchen appliance section of the store. Next to the ovens there should be a section where they sell the plugs for these ovens. Look at the size of the plug and the wire. These wires are made to handle only 50 or 60 amps. A 300 amp cable would have to be much larger, with a plug also big enough to handle that current and not melt down.

Now imagine having to carry this 300 amp charging cable with you so you can charge up your phone while traveling. That won't fit in your pocket any more.

Forget that even, just imagine having to plug your phone into a standard 120V 15A wall outlet. Those cables you use to plug your computer into the wall is now your cell phone charger cable. How big would your phone have to be to accommodate the connector that is so common on desktop computers?

I'm afraid we'll just have to put up with chargers operating in the 100 watt range, like USB-C with 20V @ 5A, and the charging times that gives us.

Re: yay math

[ledow]

To do that, it would have to do AC->DC conversion and push 600A-ish to the battery at something just over the battery voltage, though.

You're still talking about huge, dangerous current, it just wouldn't be exposed to the wall-circuit.

And, an everyday analog for that sort of current? You're looking at things like welding stations. Which can melt solid metal. Or car batteries, that can turn over an 1 tonne engine that you wouldn't be able to, faster than you can ever hope to move it by yourself.

It's still a concern.

Re:yay math

[AmiMoJo]

1500mAh = 1.5Ah

1.5Ah in 30 seconds = 1.5 * 120 = 180A at the battery voltage.

Battery voltage is 3.7V for LiPo, the type typically used in phones. So power = 180 * 3.7 = 666W.

In fact many phones have >3000mAh batteries. The OnePlus 3T is 3600mAh, which would be 1600W.

Okay, your outlet can provide 666W, but how are you going to get that to your phone and convert it to ~4V for charging the battery? Just take a look at what a typical industrial 3.3V 180A power supply looks like.

Re:yay math

[reboot246]

All of the breakers in my house are at least 20A, with larger ones for appliances that draw more power.

Re:yay math

[swillden]

A quick search tells me a phone battery typically has a capacity of something like 1500 mAh, so "charge your mobile phone in a few seconds and you wouldn't need to charge it again for over a week" sounds like something on the order of adding 5000 mAh in 30 seconds.

That would mean a current of 600 amps, assuming 100% efficiency. For reference, USB 3.0 has a max of 0.9 amps, Lightning is a little over 2, a refrigerator draws 6 amps, and your household circuit breaker will trip at 15 amps.

All this means is that the battery pack won't be the bottleneck when charging. The bottleneck will be the thickness of the wires between the voltage step-down transformer and the battery pack. I imagine we'd want to make those wires as short as possible (they'd probably end up looking a lot more like "plates" than "wires"). We'd probably also want to consider higher battery voltages.

With Li-ion batteries we usually use 3.7V or 4.2V batteries, because that works well from a Lithium ion chemistry perspective. A 3.7V, 1500 mAh battery pack stores 5.55Wh. If you have a 12V supercapacitor pack of the same capacity, it has only 460 mAh. Assuming 100% efficiency, that's 55A at 12V for 30 seconds. That's high, but it doesn't seem out of the realm of possibility. If it is, we could always reduce it a bit and take 60 seconds to charge, for example.

Regarding getting that power from your home wiring. 15A at 115V is 1725W, so your outlet can provide 5.55Wh in 11.6 seconds. But if we're charging over 30 seconds, we only need to draw 5.7A to do it.

Yay math, indeed!

Re:yay math

[swillden]

I'm afraid we will be stuck with electric cars that need many hours to charge.

Well, many minutes, anyway. Tesla's superchargers deliver up to 145kW. At that rate you could charge a Bolt from empty to full in 20 minutes (assuming no battery heating issues).

In reality home chargers don't need to be anywhere near that fast. As long as the car can recharge overnight so it's always full in the morning, that's good enough. Faster charging is really only needed on long road trips.

Re:yay math

[blindseer]

Just because you *can* charge the plates in seconds doesn't mean you have to.

That's true but since we already have batteries that can do that I fail to see any advantage to this technology. That's not saying there isn't a useful place for this technology, it's just not something that can allow anyone to charge their cell phone in seconds and run all week.

To keep the risks of arcing and electrocution low the voltages of a device would have to be in the tens of volts. I suspect that USB-C is limited to 20 volts for this reason. The same likely goes for the Firewire limit of 30 volts, automotive systems at a nominal 12 volts (which is more like 13.8 or 14.2 volts), most household thermostats at 30 volts, and so on.

When it comes to keeping the wires light, flexible, and cheap that means using copper or aluminum at small gauges. I keep some wire around for such things where it's about 16AWG on the big side, and something like 24 AWG on the small side. Those are good for max current in the range of 5 amps to 0.5 amps. Any bigger than than and they start to get heavy and stiff, even when using finely stranded wire.

So if practical considerations on conductors leaves one with the limits of 20 volts and 5 amps, like USB-C does, then going to a new technology for energy storage that can exceed this is unnecessary.

There are people in other posts that point out it is possible to use a cradle of some sort instead of a cable to allow for higher voltages and higher currents while keeping it safe. This then gets into regulatory territory where laws specify things like if a device uses voltages above a specified level then it must adhere to certain safety standards, such as double insulation, shielding, grounding, circuit breakers, arc fault detection, and perhaps more. There is also the problem that if a cradle is used then the size and shape of the phone is constrained by the cradle. I cannot imagine such a cradle being very successful even if it did in fact allow for charge times in seconds. Most people will sleep for several hours every day and simply plug in their phone to recharge every night, moving away from a perfectly suitable connector for this (like Lightning, USB-C or micro-B, or barrel connector) to a proprietary cradle adds no convenience and potentially considerable monetary cost.

The applications given for this technology, phones, electric vehicles, and wearable electronics, are actually poor uses for it. Or rather, existing technologies work just as well. I would expect this technology to be adopted only if it offers some sort of cost savings, but that was not one of the claims offered.

Super cap or super crap?

[frovingslosh]

...about the size of a finger nail and could be used in phones, electric vehicles ...

Wow. A battery the size of a finger nail that can power an electronic vehicle for days! I'm impressed. At least I'm impressed by the quantity of bullshit that the Slashdot editors will let be packed into a lame summary.

Re:Super cap or super crap?

[davidwr]

Wow. A battery the size of a finger nail that can power an electronic vehicle for days! I'm impressed. At least I'm impressed by the quantity of bullshit that the Slashdot editors will let be packed into a lame summary.

Or, that's one honkin'-big fingernail.

Re:Super cap or super crap?

[Trogre]

I think it's safe to infer that the intention is to use more than one of these in a vehicle.

Re:Super cap or super crap?

[frovingslosh]

I think it is safe to say that a battery the size of a fingernail should and would never be used in a cell phone or a vehicle. It is pretty obvious that if it works at all, and I'm not buying that it does, it should be scaled up for phone or vehicle use. The claim that a device the size of a fingernail would be used in either of the listed devices is completely bogus, and once again an obvious failure of the Slashdot editors to edit.

How many times...

[NormAtHome]

Over the years how many announcements / articles that promise some revolutionary technology have been talked about on here and yet years later they're still nowhere near being on the market. We're still waiting for those rollable / foldable displays that have been on the horizon for years, the closest that I've seen is a video of an LG prototype at this years CES show, you couldn't even hold it as they only had one and it was behind plastic; no shipping products use it yet.

There have been articles on here before about some university saying they have working nano-tube enhanced capacitors that will replace conventional batteries and promise unlimited and very quick recharges and yet still not on the market. When this gets on the market it'll be a revolution for mobile devices and probably electric cars too since they currently take 6 to 8 hours to charge, the Tesla high power wall charger promises to recharge in 3.5 hours but it's not like you can take that with you on the road.

Re:How many times...

[NormAtHome]

Is that all? I could have sworn it was more ha ha

Re:How many times...

[thegarbz]

And yet on a daily basis we have a huge amount of technology trickling down to consumers. Try and run your phone on the battery technology of 15 years ago and see how it goes.

As for the foldable displays, that isn't a technology problem, it's a WTF do we need that for problem combined with a moving goalpost problem. We've had foldable displays in research labs for years, and just before they hit the market the market itself decides to go all touchscreen.

Re:How many times...

[Whibla]

Indeed OLED technology has gone nowhere since its inception around 10 years ago.

As for those foldable displays, yeah, they don't exist either... /s

OK, so not all research is immediately practical, not all technical hurdles are easily solved but at least try to remember the things that have made it to market (and are now so common place it seems like they never didn't exist or the technology was never new) as well as the things we're still waiting on...

NOT A BATTERY

[amoeba1911]

A capacitor is not a battery! They can fulfill the same need sometimes, but it's entirely different principle of operation. Next, the article is all about how lithium batteries suck, but doesn't talk about how this new capacitor compares to other capacitors or batteries. Before you can tell if this is useful at all or just junk, you have to know at least these four key metrics:

energy density per mass
energy density volume
power density per mass
power density per volume

The article is useless, doesn't list anything relevant.

Re:NOT A BATTERY

[BenFranske]

Note that TFS states that "The high-powered battery is packed with supercapacitors..." see the definition for battery responsible for why we call groups of electrochemical cells batteries... "a set of units of equipment, typically when connected together" which is based on the traditional usage for artillery batteries. So if there are multiple supercapacitors working together it's absolutely correct to call it a battery (specifically a battery of supercapacitors, instead of a battery of electrochemical cells). Note that I doubt that the author was actually thinking along these lines when they wrote the piece, but I would argue it could still be correct.

Re:NOT A BATTERY

[thinkwaitfast]

The article is useless, doesn't list anything relevant

Much like some websites

Re:NOT A BATTERY

[friesofdoom]

battery
badr/
noun
noun: battery; plural noun: batteries; noun: the battery
1. a container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power. "battery power" synonyms: storage cell, cell "insert fresh batteries"
2. a fortified emplacement for heavy guns.

Capacitors do not store chemical energy.

Re:NOT A BATTERY

[BenFranske]

I beg to differ, chemical energy is not required. See the Oxford English Dictionary...

battery, n.
Pronunciation:/batri/
Etymology: French batterie (13th cent.) ‘beating, battering, a group of cannon’, etc. (= Provençal bataria , Spanish batería , Italian battería ), battre to beat: see -ery suffix.

1. The action of beating or battering. ...
3. The beating of drums; sometimes a particular kind of drum-beat, perhaps that giving the signal for an assault.
4. A number of pieces of artillery placed in juxtaposition for combined action; in Military use, the smallest division of artillery for tactical purposes ...
III. A combination of simple instruments, usually to produce a compound instrument of increased power; applied originally with a reference to the discharge of electricity from such a combination.
III. 9. Electr. An apparatus consisting of a number of Leyden jars so connected that they may be charged and discharged simultaneously.
III. 10. Galvanism. An apparatus consisting of a series of cells, each containing the essentials for producing voltaic electricity, connected together. Also used of any such apparatus for producing voltaic electricity, whether of one cell or more.
III. 11. Optics. A combined series of lenses or prisms.
III. 13. a. Used gen. for a collection of similar pieces of apparatus grouped together as a set

Re:NOT A BATTERY

[BenFranske]

Note, I completely agree about the first part of what you said. When describing any kind of portable energy storage to the general public it probably makes the most sense to refer to it as a battery. I disagree about the second part though, I would still argue that if there are multiple small capacitors it's correct to call it a "battery of capacitors" or perhaps a "capacitor based battery" in technical publications.

Same questions as always....

[gestalt_n_pepper]

What's the volumetric energy density compared to lithium batteries or liquid hydrocarbons?
What's the storage price per unit of energy?
How easy is it to scale up production?
Is it dependent on rare or difficult to obtain materials?

These questions are the ones that *matter*. All else is detail.

Re:Same questions as always....

[burtosis]

What's the volumetric energy density compared to lithium batteries or liquid hydrocarbons? What's the storage price per unit of energy? How easy is it to scale up production? Is it dependent on rare or difficult to obtain materials?

These questions are the ones that *matter*. All else is detail.

The energy density is likely 40-70 times lower than lithium ion batteries in even the most optimistic sense. The power density may be ok to better than lithium ions for the few milliseconds it actually functions.

It's a bad summary

[Anonymous Coward]

This isn't a new battery at all, it isn't a new supercapacitor either, its a method of making nanowire supercapacitors by growing them from 2D substrates.

But how do you explain that to Telegraph newspaper readers? Those readers won't understand that supercapacitors is already a mass market product, or that replacing batteries with them is already a niche thing.

So the Telegraph writes it up as 'magic battery', and Slashdot submitter echoes that.

Re:It's a bad summary

[NotAPK]

print it on a t-shirt and have a page three model not wear it.

SUPER batteries - SUPER discharge capacities

[rickyslashdot]

I seem to remember a story about a Kzin (in one of Larry Niven's RINGWORLD novels) referring to shorting out a high capacity (Puppeteer) battery to make a high yield destructive IED. Looks like life is catching up to SciFi - - - again -grin-
Please note that the batteries were designed by a rigorously safety-paranoid species to NOT be capable of being used in this manner - but a war-faring and destruction-motivated species STILL managed to circumvent the safeties, and managed to make it go "KA-BOOM".

If it is small it is a lie

[EmperorOfCanada]

Whenever I see a "battery" that is the size of a postage stamp, I scream BULLSHIT at the screen. Not once have I seen a postage stamp sized battery technology announcement turn into a real battery. I want a battery that does something "measurable". This is very very very easy to do an experiment that any observer can do some mental math and say, "whoa".

For instance. Heat 1 liter of water from room temperature to boiling. Then we can look at the battery in question and know pretty much its energy density. Then charge it in short order, and heat up another liter.

Short of out an out fraud there is no way to really mistake what energy it takes to raise one liter from 20 to say 99 degrees. Converting electricity into heat is quite efficient. Unless it is very very slow, heating up the water won't lose much of the energy along the way. Thus we can look at something and say, Ohhh it has over X Watt Hours of capacity. Cool. Then we can look at the volume and even approximate the energy density. So if it takes a battery the size of a coin cell to heat up 1 liter of water by 80 degrees then WOW. If it takes a battery the size of a car battery to do it, then not very good.

"A significant step forward in a tired technology"

[laserhead]

Translate: it is useless for commercial product right now, and we have no fucking idea how to get there.

Not all that much power

[davidwr]

600 amps at 5V would be about 3kW.

It would take one honking-big wire connecting the charger to the "battery" and the charger would pull at least 25 amps from the wall at 120V or 12.5 amps at 240V. Realisticly, it would probably pull a lot more. Still, it's nothing a typical clothes-dryer 240V circuit couldn't handle, so don't worry about burning down the house.

So, to market this to the average joe consumer, you just make the charging take minutes instead of seconds and make sure the charger doesn't pull more than 15 amps (1800 watts) at any given time.

If I can get my phone fully charged for a week in the time it takes me to shower and get dressed in the morning, that may be worth paying a little extra for.

Real uses

[CyberSnyder]

It could be used in phones, cars and wearables, but the first uses will be backpack power source for a friggin laser beam weapon. A flamethrower that can reach out to 1000 meters.

Re:More like vibrator

[UltraZelda64]

All I can think of when reading this thread is this:
https://www.youtube.com/watch?...

It isn't a battery

[jandjmh]

It is a capacitor. That means the voltage is directly proportional to the charge. That doesn't make it useless, but to extract most of the stored energy you need a load that can work over a 5:1 or more voltage range. (at 20% of peak voltage you have extracted 96% of the energy because the store power is proportional to the square of the voltage.) A Tesla battery pack can supply more than 1500 amps at 300 or more volts even when it is at 100% charge, and almost just as much current, at almost the same voltage, when it is at 10% or less of full charge. A giant supercapacitor that was designed as a replacement, might, just for example, have a full charge voltage of 600 volts, and be designed to work down to 120 volts, and would have to supply, in this scenario, 750 amps at 600 volts, increasing to 3,750 amps at 60 volts to deliver constant power. A challenge to the power control circuits indeed.

Re:It isn't a battery

[ledow]

Just about every device you have contains a Wheatstone bridge and a transformer or other power circuitry to come down to 3, 5, 9, 12v or whatever. The kinds of size that fit into a plug itself, most of the time.

110V or 240V. Large or small. Powerful or not. Pretty much everything has that kind of voltage conversion going on already.

Sure, you won't find one in your mobile phone just yet, but that's no different - batteries are often 3.7V and then pushed up to 5V for USB etc. and even laptops push their 19V higher for screen displays in even the cheapest of devices.

The question is not how do you convert the voltage, but how big is the battery already, how much power is in it, and what kind of current can it pump out. Past that, voltage is really at the bottom of the list of things to worry about.

Re:It isn't a battery

[friesofdoom]

"Wheatstone bridge" ?
A Wheatstone bridge is used to measure an unknown resistance. This feature is only required in a few rare circumstances, like inside a multi-meter.

Just about every device I have are not multi-meters and certainly do not contain Wheatstone bridges... You might be thinking of a diode bridge that could do with a transformer to convert AC to DC, but this only works to transform AC voltages and batteries to not supply AC. What you would need is something like a buck converter, which most digital electronics do already contain.

Scientists Create Battery That Charges In Seconds

[HeisenbergSaint]

I hope they do make this supercapacitor concept into reality, rather than just talk about it. For those of you who want to know what problems researchers of today are facing with producing these supercapacitors, then read this more indepth article here. http://saintlad.com/supercapac... Here are some recommended readings to further understand how these work and the current market situation for supercapacitors. Official Research Paper by University of Central Florida http://pubs.acs.org/doi/abs/10...

Re:Seconds

[meerling]

For a couple of decades now (more or less), I've seen discussions of using supercapacitors as batteries, but it always fails to happen because of the same major flaw, leakage. Supercapacitors lose their power rather rapidly, so you can't just recharge them and come back later and expect them to still be charged.
That seconds to charge, and last for days isn't how long it'll run a device, it's how long it'll still be charged without even being used.
There are a lot of really good researchers trying to make a supercapacitor that doesn't have that huge level of leakage, but the last improvement I saw on the science sites was several years ago, and it still wasn't enough to bring them anywhere close to being able to replace batteries are real power storage.

Re:Again...

[ledow]

Literally, until it's available in the shops, why would you care, bother or have any interest except if you were a chemist or similar.

So many battery advances have come and gone and either a) never been available or b) knocked out of the market so quickly by a superior competitor, that I gave up long ago.

Make one. Build it into a standard size / voltage cell. Sell it on Amazon or similar. Then you can worry about it. Until then, it's all pipe-dream stuff that I can neither purchase, use, or spent time worrying about.

Really?

[Maury Markowitz]

> t is uncommon for a lithium-ion battery to withstand more than 1,500 charges before it fails

Bologna. My iPhone 5S is over three years old and still has ~65% charge at the end of a day of use.

> can store a large amount of energy

The paper is behind a paywall, but thanks to Sci-Hub I could read it. It focuses entirely on power density, not energy density, but does have some comparative information in Chart F. According to that, the best-case scenario for this device is about 0.07 Wh/cm^3. A modern li-po is about 0.5, around ten times the energy capacity of this device. That is actually less than some other designs, which have approached li-po but only on microscopic scales.

So don't hold your breath, this is not a device that you will see any time soon.

Been there, done that...

[undefinedreference]

On a government project a number of years ago, we used a bank of supercapacitors to launch something very quickly off an average vehicle battery every minute or so.

It sounds great, but we also had the damned things explode quite spectacularly. And by that, I mean, if we didn't have it inside a very tough metal box, shrapnel might have killed the tech that was near it when it went.

Not that lithium batteries are much better; I've seen some really exciting fires when the LiPo batteries in R/C race cars fail... If you thought a phone battery bursting into flame was exciting, you have never seen one of these go up.

So

[gzuckier]

By battery we mean capacitor.

Mice

[DrYak]

Actually, the technology HAS BEEN used in computer mice.
(which do not use that much power, and thus the lower energy density of older supercaps wasn't such a big deal).

of course, the supercap is small in order to fit into a computer mouse.
last I've heard about these (a couple of years ago), the mouse would charge literally in seconds, and could be used for a couple of hours in a go.

So if you leave the mouse on its charging craddle for a few seconds whenever you make yourself a coffe (or go to the toilett, or even just stretch your legs) you never have an empty mouse.
(as opposed to a mouse with a lithium battery, which won't be fully charged that fast enough)