Posted on 12/27/2007 11:43:25 PM PST by PeaceBeWithYou
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.
Not seeing where you are getting that statistic, but I doubt depreciation is factored in.
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
Why the smart money is on Duncan Hunter
http://www.freerepublic.com/focus/f-news/1926032/posts
In this poll Hunter is up 3% and even with Paul and Thompson.
http://www.wxyz.com/news/local/story.aspx?content_id=3481ef60-8195-46a9-af04-b87b907bcfdd
I thought I was quoting your number, you may have been quoting someone else, but $.7 per KWH is 70 cents to me.
I pay 10 cents per KWH where I live. 70 cents for natural gas generated power seemed a little high, It must include depreciation because I can generate electricity for about that cost with a gasoline powered generator.
Ah....That was a typo on my part. I was referring to the 4.7 Kw (max) electrical output of the unit, as being a “fair” amount of electricity to run things with, during a blackout.
Fair, as in, it’ll keep the fridge , TV, a couple of lights and a fan ruuning...but it won’t tun all of a family houses’ appliances, and certainly not a Central AC..not even with a window AC..if all the other stuff is on too.
Instead of typing ‘4.7’, I typed ‘$.7’
“I do wonder how long it would take to recharge the nano-li-ion Tesla with a range of 800 miles.”
It always comes down to time and money. If these nano-wire batteries cost a fortune, then it won’t matter that a 200lb battery can take you 800 miles. Or if they have to be charged slowly like tradional Li-Ion batteries, they are also a non-starter. I’d rather have a set of A123 or AltairNano batteries that can be recharged in 10 minutes, even if they do weigh 600lbs to go 200 miles.
An electric airplane, on the other hand, is a different story. Weight will be king in that application.
Toshiba to release fast charging battery
December 12, 2007
The company said its Super Charge ion Battery can recharge to 90 percent of full capacity in less than five minutes. Tokyo-based Toshiba (OTC: TOSBF) announced that it planned to release a fast charging lithium ion battery early next year for use in industrial vehicles and other applications.The company said its Super Charge ion Battery can recharge to 90 percent of full capacity in less than five minutes.
Toshiba said it plans to make the battery a mainstay of its industrial systems and automotive products businesses, with the first system to be shipped in March 2008.
"The excellent performance of the SCiB will assure its successful application in industrial systems and in the electronic vehicles markets as a new energy solution," said Toshiharu Watanabe, CEO of Toshiba's Industrial Systems group.
"In terms of environmental impacts, the SCiB offers a long life that will reduce waste."
The company said its battery management system monitors voltage and temperature in order to protect the cells and balances the state of charge in each cell.
Toshiba expects its batteries to be used in battery-powered bicycles, motorcycles, automated guided vehicles, electric forklift trucks and construction machinery.
The company also said the new system is a promising candidate for emergency power sources, electric power regeneration in wind power systems and stabilization of electric power supply, with applications in hybrid and electric cars also planned.
Heck, I have a girlfriend who swears she can recharge batteries by putting them in the microwave oven.
I’ve never tried it, as I like my Microwave, kitchen, house, and personal belongings.
Don’t feel bad. I’m still waiting for my ride on the Pan Am Clipper Shuttle to the Hilton Space Station. Should have been here over 6 years ago....still waiting.
This is also accomplished by altering the duty cycle of the charger. I have an R/C battery charger that uses this technology for charging NiCds and if they are cycled properly I've had them last for 15 years.
If this tech is for real, LiPo should be phased out.
The beauty of LiPo is their size and weight advantage. I'm seeing LiPo batteries showing up in the R/C world that are tiny, but give power similar to much larger NiMH and NiCD batteries.
Another thing to consider with NiCd's is the damaging heat may not come from charging. If you live in Phoenix or Yuma you may very well see a significantly shortened battery life just by virtue of being exposed to summer heat. It doesn't take that much heat to do serious harm to NiCads.
Have you heard of Europositron? They have a theoretical approach to developing a rechargable aluminum air battery. It also promises energy density similar to what nanofiber silicon lithium is promising.
I really want a normal sized vehicle with good performance and 500+ mile range that doesn’t run on imported fuel.
Yes, but it doesn’t have the energy density of the nanowire li-ion battery described here. A123 Systems already has its fast-recharge li-ion battery on the market — for a year now. But a battery pack that will run a small electric car for 200 miles weighs 600lbs — compared to about 50lbs of gasoline.
The combination of fast-recharge and high energy density would be great. The nanowire energy density comes close to gasoline. That would mean you don’t need to carry a huge weight around with you on the road or in the air.
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