January 15, 2008 7:35 AM PST

A tenfold improvement in battery life?

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.

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Some thoughts
How the energy density compare with fossil fuels? There was some talk about running a laptop on a fuel cell instead of a battery.

OTOH, can this be adapted to electric cars. With a current range of somewhere around 50-120 miles on a single charge they are pretty much dead. But if that can be extended to 500 to 1200 miles now that would be a very practical car, able to take long weekend vacations on a single charge, or at least have a range that would allow one to drive all day and recharge overnight to continue the next day.
Posted by k2dave (213 comments )
Reply Link Flag
Sounds like its not ready yet to me.
I would imagine the fuel cell battery was theoretical. I don't think there is one small and portable as of yet. Maybe someday. This story sounds like its years from a release too. Its still in a lab. Sounds interesting though. I am kind of wanting to see the schematics on it to see how they were able to keep the silicon from fracturing while in this tree pattern.

I am also kind of wondering how many other developments are sitting in limbo because of the tools to get the job done were nonexistent at the time of R&D.
Posted by Astinsan (132 comments )
Link Flag
Energy density
Current Li-ion energy density is 600 joules per gram.

Gasoline is 47,000 joules per gram.

Even a 10-fold increase puts batteries far behind gasoline.
Posted by b_baggins (772 comments )
Link Flag
And for a car: 400 mile range.
Developments like this are just what we need to get the carbon out of the air.
Posted by disco-legend-zeke (448 comments )
Reply Link Flag
..and into the nanofibers..
...where it belongs ;)
Posted by punterjoe (163 comments )
Link Flag
Car Battery
Good point. Why not apply to car battery? These guys should hit
that market first. Unless the amperage required for a car batter is
too high for this technology?
Posted by zmonster (272 comments )
Link Flag
Yeah, and kill all
plant life on this planet, not to mention every organism that depends on plant life. CO2 is an essential component of the atmosphere for supporting life on this planet, and contribution of CO2 produced by human activity hasn't changed atmospheric CO2 concentrations by a huge amount.
Posted by atmx2000 (16 comments )
Link Flag
that was my first thought!
Yea, first thing I thought when I saw this article wasn't laptop batteries, but car batteries and the extension of the electric vehicle range (far more important than laptops in my opinion).

And to the fool who says all plant life will die...uh...all that life existed before the automobile and the industrial revolution. Don't tell me you're so stupid as to think plants need automotive CO2 to survive.
Posted by jrm125 (334 comments )
Link Flag
and in a small un-marked office.........
in the back of the headquarters of big oil company......a plainly dressed man sits reading this same article.....his eyebrow goes up........he picks up the phone........he dials...it rings on the other end....and rings.....and rings.....finally someone answers....."We have a problem...."....He explains

"OK, we'll take care of it." <CLICK> dialtone............
Posted by ccblue (7 comments )
Link Flag
Where do you get your electricity?
How do they generate the electricity? Would they not emit anything? Yes it's more efficient but it's not totally green, yet.
Posted by dream_fly (560 comments )
Link Flag
Re: Wrong Element at Hand
How would the implementation of silicon nanowires impact the amount of carbon (in the form of carbon dioxide) in the atmosphere?
Posted by quirK (53 comments )
Link Flag
400 miles per charge?
400 miles to the charge is perhaps a ten-fold improvement over a lead-acid cluster pack.

The Ronaele-tuned Ford Mustang '300e' goes slightly more than 100 miles per charge. 100 miles to the charge is more or less the current benchmark for electric vehicles be they sporty or civil.

We're pushing 1000 miles to the charge when this stuf goes public. Most commercial truck drivers will drive 600 within the alloted 10-hours a day limit for Class-A driving.

This is a huge developement for the auto industry and frees engineers from performance/fuel-economy restraints in a very big way. In ten years, when gasoline hits $10 a gallon a one cares, you could very well be taking cross-country DisneyLand trips on a single charge.

With solar panel roofing, 'carbon fiber look' solar panel hoods, and pohto-voltaic 'tint-look' rear glass, we could very well have cars capable of running indefinitely before 2030.
Posted by Viktor King (9 comments )
Link Flag
Yep, that evil plant fertilizer
C02. The most dangerous substance on the planet.
Posted by b_baggins (772 comments )
Link Flag
Carbon out of the air?
Electric cars will get carbon out of the air when we decide to get serious about nuclear fueled power plants. Solar, wind, geothermal, and the rest can supply only a small fraction of the electric energy, and in a carbon free way, that would be needed if any appreciable portion of drivers were to use electric cars
Posted by FowlerE0 (1 comment )
Link Flag
See more comment replies
What do Lockheed Martin, Zenn Motors, Bill Joy, Al Gore and the VC firm Kleiner Perkins Caulfield & Byers all have in common?


EEStor Inks Deal with Lockheed Martin

Cedar Park, Texas-based EEStor signed an exclusive international deal with defense contractor Lockheed Martin, EEStor said Wednesday. Under the new deal, Lockheed Martin will integrate EEStor's ceramic batteries into military applications. EEStor claims its batteries potentially have 10 times the energy density of lead-acid batteries at half the price (see Earth2Tech post and VentureBeat post). EEStor plans to begin mass production by the end of this year.
Posted by USDecliningDollar (243 comments )
Reply Link Flag
EEStor and ZENN
Good observation. The EEStor "batteries" (actually, ceramic-
based capacitors) are larger and unfeasible for use in smaller
applications. EEStor has also delayed production for a number of
months, with no explanation.

The lithium batteries that are presented here have not been
shown as for automotive use, so that may be a presumption on
a reader's part. Being smaller they could revolutionize every
small electronic that you currently use. Imagine a cell phone
that wouldn't need charging for a month.
Posted by sheldonc (7 comments )
Link Flag
10 times
OR, it could be used in a laptop to power a version of Vista that requires ten times the processing power and ten times the RAM, for 2 to 3 hours.
Posted by fokwp (44 comments )
Reply Link Flag
Uh, don't know what Vista you are using but...
Uh, don't know what Windows Vista you are using but my Dell 1405 w/2Gb RAM running Vista Business has BY FAR the best battery life of any laptop I owned prior, all with much less RAM and much slower processors.
Posted by PragmaticIdealist (10 comments )
Link Flag
Charge Time???
This "news" is NOT new !! Secondly, in earlier reports and also now I haven't heared one single word about what time it takes to charge the pack fully. If thats 10-times as well then the usability is limited. Not worthless by no means because you can have a second battery provided you can access it every time the laptop is running out of power. But an exchange system like with glass bottles can be built.
Posted by cnet57 (2 comments )
Reply Link Flag
Posted by JTRACEY5 (2 comments )
Reply Link Flag
Are we supposed to take your concerns serious?
Are we supposed to take seriously the concerns of someone regarding computer-related topics that is so ignorant of appropriate online communication that they SHOUT EVERY WORD THEY TYPE?!?!?
Posted by PragmaticIdealist (10 comments )
Link Flag
Take a deep breath, relax, turn the caps lock off. The problem with batteries burning was metal shavings from bad manufacturing polluting the paste that makes up the battery. Increasing the electron storage density this way, has no effect on flammability. Those two issues are mutually exclusive.
Posted by bemenaker (438 comments )
Link Flag
Getting dangerous
This is a very exciting development. However, this kind of energy density is starting to be dangerous. Energy is energy - if you throw this battery into a fire, you'd better stand back. Would you want it under the seat of your car in a crash? Will homeland security let it onto an airplane? I suspect safety protections will reduce the factor of 10 to 5-7 by the time this reaches the public.

Still worth celebrating, though.
Posted by homunq (1 comment )
Reply Link Flag
That' true, but
that is a good point, especially with all the cases of exploding batteries this year. Still, 5-7 times the battery life is still a pretty good trade off for just a couple safety precautions.
Posted by toreduce (6 comments )
Link Flag
Energy density
As some smart guy pointed out earlier, gasoline would still have several times the energy density even if you increase the battery's energy carrying capacity by ten fold.

The trick is preventing cascading chain reaction for the battery by proper design.
Posted by Joe Real (1217 comments )
Reply Link Flag
All about fuel efficiency.
I think most of you forget about the fuel efficiency. Yes, it is a good improvement of energy-to-weight ratios of the Li-ion battery. But is still far away from gasoline. How's about fuel efficiency? Any better than the "poor" existing Li-ion battery?
Posted by ray in mo (1 comment )
Reply Link Flag
ICE only uses ~10% of the engergy in petrol.
Most of the energy is wasted on friction, heat, noise and etc.

ICE hasn't changed much in 100 years. It is bit more efficient now than before with ECU, variable valve timing, and etc, but it's still only improving what is at a core inefficient process to turn energy in petrol into mechanical rotational energy.
Posted by knarfl1 (23 comments )
Link Flag
Batteries for Cars
Hi Everyone,

Firstly thanks for reading my story, it's been hugely popular around the network.

Since there has been so many comments, I will try and address some of your questions.

Even with a tenfold increase in battery life, these new Li-Ion batteries would not compared to the energy density (in kilojoules per gram) when compared to octane (read, petrol).

By my calculation a standard Li-Ion batteries comes out at around 500 joules per gram, as such this battery could be up to 5000 joules per gram.

Compare that to octane, 47,000 joules per gram, this still gives it about 10 as much energy per unit weight as these improved batteries.

Octane can be generated as a biofuel, which (at least in theory) makes it carbon neutral.

In regard to electric cars, it is my opinion the best technology for electric cars is still hydrogen based fuel cells (although methanol fuel cells are pretty good).

However it could still be great for laptops, ipods etc, were fuel cells aren't practical.

-- Alex Serpo, ZDNet Australia.
Posted by Alex Serpo (1 comment )
Reply Link Flag
I hope this breakthrough will materialize
It has the capacity to turn the whole automotive industry. 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 (as reported earlier in CNET), 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. 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 or solar.
Posted by Joe Real (1217 comments )
Link Flag
You forgot one thing
Electric cars are much, much, more efficient than internal combustion engine cars.

So you will only need 1/3 the energy to move the vehicle the same distance due to increased efficiency.

Now suddenly the gap isn't so big!
Posted by Clouseau2 (329 comments )
Link Flag
Nanotech == <3
Oh nanotech. Is there nothing you can't do. :-)
Posted by Jonathan (832 comments )
Reply Link Flag
So...GM or Texaco?
Who do you think will buy and sit on the technology? :p
Posted by Rerednaw (13 comments )
Reply Link Flag
At Last
Now we're talking! It's been ridiculous having so-called 'portable computers' that can't make it to the end of an airline trip on a single charge. Perhaps with this technology and more advanced screens, laptops will come of age. Though I suspect some kind of foldable computer will sooner or later supplant them- they are simply too big, though the current non-foldable smaller ones too fiddly.
Posted by Starfires (157 comments )
Reply Link Flag
The best thing to do
For a lap top it would be best to have a universal batter that could fit almost all lap tops 12 inches and bigger because then it would cost much less to produce.
Posted by Drummer102 (3 comments )
Reply Link Flag
Now how about that Mr. Fusion?
I remember hearing recently that researchers are also finding ways to make fuel from garbage. Breakthroughs like these are really amazing! I just hope they keep it reasonable as far as pricing goes when these things hit the commercial market. A monopoly does not a good MSRP make.
Posted by Icehearted (14 comments )
Reply Link Flag
Well it seems Prof. Cui have resolved a 30 year old enigma. At present, many companies are vying for the ultimate Lithium battery; ie: higher power-to-weight ratio, shorter charge times, and more discharge power. All this in light of the recent resurection of electric cars. I sincerely hope the silicon nanowire based anode theory doesn't turn out to be rhetoric.
Posted by Keyup2 (2 comments )
Reply Link Flag
People keep saying cabon dioxide (CO2). Actually, it's a poisonous gas given off by a vehicle's exhaust known as cabon monoxide (CO). People have actually locked themselves in garages and used this gas to commit suicide.
Posted by Keyup2 (2 comments )
Reply Link Flag
I have been trying to go again, hope I can help.

Posted by 2dealsnet (2 comments )
Reply Link Flag
General users access to mobile phone lithium-ion battery, battery on the outside can see in addition to casing, there is a few metal contacts, as shown in the "battery positive, battery negative" is the battery positive and negative output.
Posted by 2dealsnet (2 comments )
Reply Link Flag
This is good news.
Posted by 2deals (2 comments )
Reply Link Flag
This is good news.
Posted by 2deals (2 comments )
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