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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.
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.
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?
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.
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
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!
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Yes. The article was terrible. She almost tripled the energy density of supercapacitors. From her paper:
"National Security is the chief cause of national insecurity." - Celine's First Law
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.
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.
"National Security is the chief cause of national insecurity." - Celine's First Law
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.
Property for sale in Nice, France
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.
but unless she has achieved actual breakthroughs in the field, this is again not nearly as newsworthy as the headline suggests.
She has. 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.
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)