Imagine extending the range of plug-in hybrids to 400 miles, the Aptera could get 1,200 miles on a singe charge. Cell phones lasting 80 hours instead of 8 hours. Laptops for one week instead of one day.

Joe

A tenfold improvement in battery life?
Stanford researchers say silicon nanowires could help extend the life of a lithium ion battery for laptops from 4 hours to 40 hours.
By Alex Serpo
Special to CNET News.com
Published: January 15, 2008, 7:35 AM PST

Stanford University researchers have made a discovery that could signal the arrival of laptop batteries that last more than a day on a single charge.

The researchers have found a way to use silicon nanowires to give rechargeable lithium ion batteries--used in laptops, iPods, video cameras, and mobile phones--as much as 10 times more charge. This potentially could give a conventional battery-powered laptop 40 hours of battery life, rather than 4 hours.

The new batteries were developed by assistant professor Yi Cui and colleagues at Stanford University's Department of Materials Science and Engineering.

"It's not a small improvement," Cui said. "It's a revolutionary development."

Citing a research paper they wrote, published in Nature Nanotechnology, Cui said the increased battery capacity was made possible though a new type of anode that utilizes silicon nanowires. Traditional lithium ion batteries use graphite as the anode. This limits the amount of lithium--which holds the charge--that can be held in the anode, and it therefore limits battery life.

Silicon anodes have the "the highest theoretical charge capacity" according to Cui's paper, but they expand when charging and shrink during use: a cycle that causes the silicon to be pulverized, degrading the performance of the battery. For 30 years, this dead end stumped researchers, who poured their battery life-extending energy into improving graphite-based anodes.

Cui and his colleagues looked at this old problem and overcame it by constructing a new type of silicon nanowire anode. In Cui's anode, the lithium is stored in a forest of tiny silicon nanowires, each with a diameter that is a thousandth of the thickness of a sheet of paper. The nanowires inflate to four times their normal size as they soak up lithium, but unlike previous silicon anodes, they do not fracture.

Cui said there are a few barriers to commercializing the technology.

"We are working on scaling up and evaluating the cost of our technology," Cui said. "There are no roadblocks for either of these."

Cui has filed a patent on the technology and is considering formation of a company or an agreement with a battery manufacturer. He expects the battery to be commercialized and available within "several years," pending testing.

Alex Serpo of ZDNet Australia reported from Sydney.

http://www.news.com/2100-1041-6226196.html?tag=tb

My other comments:

This type of battery improvement has the capacity to turn the whole automotive industry and help revive the entire US economy. There could be upheavals too, so many would be affected, particularly the oil tycoons in the US.

With this breakthrough. a vast majority will be able to use the plug-in cars with increased range compared to what is possible now. The current 40 mile range of converted plug-ins is not sufficient. Increase that range to just 5 times, it will be useable by more than 95% of the population who go to work daily.

It is true that we might use carbon-based fuel in the various electric plant to power up these cars, but then those CO2 generating plants will become a point source which are easier to control. If gasoline or petrols were used by cars, the CO2 emissions would be everywhere and they cannot be captured easily. Whereas if those CO2 comes from power plants, they can be easily recaptured, like producing baking powder http://www.news.com/Can-baking-soda-curb-global-warming/2100-13838_3-6220127.html?tag=nefd.lede
trapping in some rocks to solidify as limestone http://www.msnbc.msn.com/id/22506764/
or can be used to enhance production of biodiesel from algal cultures where CO2 is recaptured, and still others that can convert CO2 into fuel building blocks by the use of catalysts, water and lots of concentrated sunshine http://www.sciencedaily.com/releases/2007/04/070418091932.htm

The point is that if CO2 emissions are pinpoint rather than scattered, it is easier to deal with. Besides, the conversion efficiencies of power plants are much better than internal combustion engines. And we don't need to literally use fossil fuels to generate electricity. We have alternatives that are cheaper than nuclear sources such as those solar thermal plants, wave, tidal, hydroelectric, underwater ocean or sea currents, geothermal, wind and biomass energy to name a few.

Commuting to work is one of the major producer of carbon dioxide. If these are replaced with electric cars that are zero emissions which will be possible with increased range, then it would be revolutionary if the price of these new batteries become affordable. The use of all zero emission vehicles for daily commuting would truly have dramatic impact on carbon emissions. At a good range of 400 miles, that would even include the out of town escapades and vacation. Imagine the Aptera vehicle that gets 120 miles to a charge, and could now be extended to 1,200 miles. Now I can commute to Canada from California without having to pay for blood oil.

Still another uses for these batteries would be for energy storage to even out the variabilities of wind, wave or solar energy.

More follow-up news and details of the revolutionary battery:
http://cosmiclog.msnbc.msn.com/archive/2008/01/17/586070.aspx

A 'revolution' in batteries
Posted: Thursday, January 17, 2008 8:20 PM by Alan Boyle
If you've ever rushed to save your files before your laptop battery gave out, or scrambled to recharge your iPod, or wished out loud for the resurrection of the electric car ... relief is in sight.

Yet another battery breakthrough is on its way to market, taking its place alongside improved hybrid-electric vehicles, the promise of ultracapacitor systems and even better AA power cells. Next-generation batteries could well last several times as long as current power packs, thanks to nanotechnology.

"This idea will have a really high impact on battery technology," said Stanford chemist Yi Cui, who is the lead researcher behind a study appearing in this month's issue of Nature Nanotechnology. "This is really revolutionary."

The key innovation involves using silicon nanowires instead of the usual carbon to store energy in a lithium-ion battery's anode.

Silicon has more than 10 times as much charge capacity as carbon. If commercial batteries could live up to that performance level, you could theoretically be running your laptop for 20 to 40 hours straight rather than the typical two to four hours. An electric car could go 400 miles on a charge rather than 40 miles.

Of course, the reality is more complex than the theory. But more about that later. The first question is whether this technology is actually for real. If silicon is that good at storing electrical energy, why isn't it being used already?

That's where nanotechnology makes the difference: For years, engineers have been trying to harness silicon electrodes for battery applications. But the problem with silicon is that its volume bulks up by a factor of four when you add the lithium - and then shrinks by the same factor when power is extracted. That quickly pulverizes an electrode made of silicon film or particles, rendering the battery useless.

Cui and his colleagues took a different approach: They grew nanowires of silicon directly on a stainless-steel plate. Each wire was about 90 nanometers wide, or a thousandth of the width of the typical human hair. When the filaments were filled with lithium-ion power, they thickened up and lengthened into curls, like tiny spongeworms - but they retained their resiliency through dozens of power cycles.

"This idea really made these silicon materials possible to be used in battery technology," Cui said.

Challenges still lie ahead: First of all, Cui's team focused on retooling the anode, which is just one of the electrodes in a battery. To get the full tenfold improvement, Cui told me, "you would need to improve also the other electrode ... but with one electrode improvement, you can improve a lot already." For example, you could make the anode smaller, leaving more space for a bigger cathode.

Cui's team also found that there was a one-time capacity drain after the first charge. But that's no biggie. The nanowires' storage capacity was still about eight times higher than carbon, Cui said. "This won't prevent this technology from going forward," he said.

On the plus side, silicon-nanowire batteries wouldn't have to look like the battery bricks that are typically used in laptops or cell phones. "It's a fundamentally different structure from the current technology," Cui said. And that could result in batteries that are better-shaped to conform to the available space.

Cui said a patent application has been filed for the technology, and he's considering starting up a company to commercialize the concept. So when might silicon-nanowire batteries hit the market? "I'm thinking in the next three to five years," Cui said.

Some companies are already knocking on the lab door. Cui acknowledged that Tesla Motors, the company working on an all-electric sports car, is just one of the outfits expressing interest. "There are lots," Cui told me, "but it's better not to mention their names now."

To learn more about Cui's work, check out this interview at GM-Volt.com and this story in The Stanford Daily. In addition to Cui, the authors of the Nature Nanotechnology paper include Candace Chan, Halin Peng and Robert Huggins of Stanford University, Gao Liu of Lawrence Berkeley National Laboratory, and Kevin McIlwrath and Xiao Feng Zhang of Hitachi High Technologies.