Posted on 12/19/2007 5:29:22 PM PST by decimon
Stanford researchers have found a way to use silicon nanowires to reinvent the rechargeable lithium-ion batteries that power laptops, iPods, video cameras, cell phones, and countless other devices.
The new version, developed through research led by Yi Cui, assistant professor of materials science and engineering, produces 10 times the amount of electricity of existing lithium-ion, known as Li-ion, batteries. A laptop that now runs on battery for two hours could operate for 20 hours, a boon to ocean-hopping business travelers.
"It's not a small improvement," Cui said. "It's a revolutionary development."
The breakthrough is described in a paper, "High-performance lithium battery anodes using silicon nanowires," published online Dec. 16 in Nature Nanotechnology, written by Cui, his graduate chemistry student Candace Chan and five others.
The greatly expanded storage capacity could make Li-ion batteries attractive to electric car manufacturers. Cui suggested that they could also be used in homes or offices to store electricity generated by rooftop solar panels.
"Given the mature infrastructure behind silicon, this new technology can be pushed to real life quickly," Cui said.
The electrical storage capacity of a Li-ion battery is limited by how much lithium can be held in the battery's anode, which is typically made of carbon. Silicon has a much higher capacity than carbon, but also has a drawback.
Silicon placed in a battery swells as it absorbs positively charged lithium atoms during charging, then shrinks during use (i.e., when playing your iPod) as the lithium is drawn out of the silicon. This expand/shrink cycle typically causes the silicon (often in the form of particles or a thin film) to pulverize, degrading the performance of the battery.
Cui's battery gets around this problem with nanotechnology. The lithium is stored in a forest of tiny silicon nanowires, each with a diameter one-thousandth the thickness of a sheet of paper. The nanowires inflate four times their normal size as they soak up lithium. But, unlike other silicon shapes, they do not fracture.
Research on silicon in batteries began three decades ago. Chan explained: "The people kind of gave up on it because the capacity wasn't high enough and the cycle life wasn't good enough. And it was just because of the shape they were using. It was just too big, and they couldn't undergo the volume changes."
Then, along came silicon nanowires. "We just kind of put them together," Chan said.
For their experiments, Chan grew the nanowires on a stainless steel substrate, providing an excellent electrical connection. "It was a fantastic moment when Candace told me it was working," Cui said.
Cui said that a patent application has been filed. He is considering formation of a company or an agreement with a battery manufacturer. Manufacturing the nanowire batteries would require "one or two different steps, but the process can certainly be scaled up," he added. "It's a well understood process."
Also contributing to the paper in Nature Nanotechnology were Halin Peng and Robert A. Huggins of Materials Science and Engineering at Stanford, Gao Liu of Lawrence Berkeley National Laboratory, and Kevin McIlwrath and Xiao Feng Zhang of the electron microscope division of Hitachi High Technologies in Pleasanton, Calif.
Detroit will buy it up and bury it, because it could lead to the electric car. Who made Steve Guttenberg a star?
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It’s the Jack Bauer cellphone batteries!
He beats on people with a cell phone?
I think they’d be pretty great to have on a number of different products, but could you imagine what kind of explosion it would be if one of these things went ‘boom’?
California doesn't like electricity or things electric.
We will never hear about this again.
His cell never went dead did it?
This is very exciting,,imagine a laptop that would run for a day!
I wouldn't be surprised ( :^D ), but no, I meant the the magic cellphone batteries he uses that never run dry no matter long he uses the phone.
Exactly. It would be nice to actually have enough juice to get some serious work in on a long flight.
Kinda like the TV cowboys whose six-shooters never ran out of bullets.
Tech Ping...
bump
Talk about brownouts....wait ‘till EVERYBODY plugs in to re-charge at the same time.
Every little increase in the amount of usable energy being stored counts.
The Chinese will steal it first.
What I like about this story is that it isn’t filled with words like might, may, could, if sucessful would. If this story is accurate I might actually be able to buy one of these things in a couple of years.
Someone posted something about a power company building battery substations to handle increasing demands. IIRC, the idea is that excess electricity produced overnight will be used to charge the batteries which will then be used the next day to supply more electricity when it's needed.
I hope the above is reasonably clear.
I hope they are not too expensive. If not then both hybrid vehicles and solar power should become more feasible.
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