Posted on 12/23/2007, 2:35:38 AM by dangerdoc
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."
So what is the wholesale price of lithium these days?
Ping for later
This one gets a “WOW”... not only will this permit batteries with big-time life, but smaller ones for devices that might not have been able to use batteries before due to size-vs-life constraints. I’d say it’ll be HUGH.
Some real whiz-bang technology here.
Think I heard on the Kim Komando show today that this would give the battery on your laptop up to 40 hours use before a recharge was necessary.
Of course this would have never have happened if the Democrats did not pass the new Energy Bill. Nancy Pelosi can claim she invented it.
I also wonder what kind of fires these batteries will generate.
All she probably did was take the current average for a laptop of about 4 hours and multiply it by 10.
Excellent. Now China can steal the technology and provide the world with it’s in-house designed miracle batteries. Very cool.
Just think how long a hearing aid batter could last.
but will it run my van...?
The combination of this with recent price breakthroughs in solar power seems quite interesting
What about making a big battery for an electric car. This could solve our energy problems.
And to think Big Oil is still sitting on that carborator that runs on water.
LOL!
How so? Batteries don't make energy, they just store it. It also takes almost twice as much energy to go a mile in an electric car as a diesel car, due to the high transmission losses involved in the use of electricity.
Show some sympathy, ok? How would you like to spend thirty years sitting on a carbuerator?
bmflr
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According to Intrade, the winner of the December 12th GOP debate was... Duncan Hunter.
http://www.freerepublic.com/focus/f-news/1938773/posts
As a Big Pharma employee of a company making Lithium tabs and caps, I can tell you that it's CHEAP.
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