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Portables Power Hardware

Nanowires Boost Laptop Battery Life to 20 Hours 238

Posted by ScuttleMonkey
from the more-bang-for-your-buck dept.
brianmed writes to tell us that Stanford researchers have created a new use for silicon nanowires that promise to reinvent lithium-ion batteries. "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. [...] 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."
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Nanowires Boost Laptop Battery Life to 20 Hours

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  • by farnsaw (252018) on Wednesday December 19, 2007 @12:28PM (#21753308) Homepage
    Rather than tripling the life of a current battery, I can see this being used to power a laptop off a battery the size of a current cell phone battery and shrinking cell phone batteries to the size of a nickel. This will drastically reduce the size of several of our common devices such as Bluetooth headsets, cell phones, iPods (and other MP3 players), digital cameras, etc. In many such devices, the battery is still the single largest and heaviest component and being able to shrink this by a factor of 3-5 will drastically affect the size and weight of them.

  • patent (Score:2, Insightful)

    by ageforce_ (719072) on Wednesday December 19, 2007 @12:29PM (#21753326)
    why does the assistant professor get the patent?
    I would say he was employed by Stanford. So Stanford should receive the patent. If his research-money was provided by a public institution (some sort of grant), then either the research should be public (patent-free), or the patent should be somehow associated to the country.
    I don't see why he gets to profit from the discovery. (After all he was payed to do that. It would have been bad, if he hadn't found anything.)
  • by MightyYar (622222) on Wednesday December 19, 2007 @12:33PM (#21753388)
    I'd say that increasing battery performance by 10x is EXACTLY the kind of thing that the patent system is built for. This development can only be good for society, even if we have to wait a few years before it becomes generic.
  • Re:patent (Score:1, Insightful)

    by Anonymous Coward on Wednesday December 19, 2007 @12:36PM (#21753436)
    You invent something like this (or anything for that matter), then see if you are still of the mindset that people shouldn't own their own work. Enough of this "Information wants to be free" nonsense.
  • by iamacat (583406) on Wednesday December 19, 2007 @12:42PM (#21753532)
    It's a shame that enough power to cause a massive explosion can only power a device that, for the most part, just displays text for 3 hours. We really need to rethink what a computer does when someone reads e-mail or browses the web. With an e-paper display, processor, disk and a WiFi radio should just briefly power themselves on when the user goes to a new URL and then completely shut down, yielding weeks of typical use on a single charge. Audio and video playback can be achieved by a dedicated chip and achieve playback times of the latest iPods. If users also want to use the same laptop as a desktop replacement, it can an internal PDA-like subsystem with it's own low power CPU, RAM and flash storage that synchronizes some directories with the main disk. Users can then choose weather they need high performance or long battery life at the moment and control either subsystem from the same display, keyboard and trackpad.

    With clever engineering it should be possible to make a laptop exclusively used in low power mode solar powered if it's normally left out when not in use.
  • by Sitnalta (1051230) on Wednesday December 19, 2007 @12:47PM (#21753584)
    1) How much will they cost
    2) How long does it take to charge
    3) How many charges can you get in its lifetime.

    If any one of those is a major deficiency, the technology will be worthless. Since they didn't immediately bring up use in electric cars, I'm guessing there's currently a fatal flaw that applies to one of those questions.

    My money is still on ultra-capacitors.
  • by gweihir (88907) on Wednesday December 19, 2007 @12:47PM (#21753592)
    Actually energy contents is already higher than some explosives. The current limitation is that you cannot releaste the energy in a short burst.
  • by InvalidError (771317) on Wednesday December 19, 2007 @12:55PM (#21753724)

    Rather than tripling the life of a current battery, I can see this being used to power a laptop off a battery the size of a current cell phone battery and shrinking cell phone batteries to the size of a nickel. This will drastically reduce the size of several of our common devices such as Bluetooth headsets, cell phones, iPods (and other MP3 players), digital cameras, etc.

    Great, more unworkably small displays, keypads and other tactile/visual HIDs.

    I think many of those devices have already reached the limit where size is impeding usability and ruggedness. I personally cannot stand squinting at video on sub-3" LCDs and hate my current cell phone's ~1" wide keypad.
  • by eharvill (991859) on Wednesday December 19, 2007 @01:45PM (#21754380)

    Great, more unworkably small displays, keypads and other tactile/visual HIDs


    Or, keep the device sizes the same, reduce the battery size and add more functionality/technology/features/etc in said device.

    Shrink a battery in a laptop and you can have enough extra room to have an additional 2-3 hard drives if one wanted.
  • by Pope (17780) on Wednesday December 19, 2007 @01:45PM (#21754382)
    Are you joking? Batteries have come a LONG way since WW 2! Granted, electronics have become more powerful and energy-efficient as well, but you can't deny the progress made. Look at the life of a current generation set of Lithium AAs.
  • by OwnedByTwoCats (124103) on Wednesday December 19, 2007 @02:14PM (#21754758)

    Gasoline 9,700 12,200

    ...
    Secondary LiOn Polymer 300 130 - 1200
    Do the rest of the math.

    300 * 10 is 3000, so gasoline still stores three times as much potential chemical energy as the battery. But converting chemical potential energy into motion through an internal combustion engine is about 30% efficient, while power electronics and electric motors net between 80 and 95% efficient.

    • Battery: 3000 * 0.8 = 2400
    • Gasoline: 9,700 * 0.3 = 2910
    so getting batteries to within 80% of gasoline (i.e. same volumetric energy density as a vehicle fuel as ethanol) really is revolutionary.


    If these Li-Ion batteries are on the lighter end of the scale, the energy/weight figures could be extrordinary.

    • Battery: 1200 * 10 (improvement from research) * 0.8 (efficiency) = 9600 watt-hours traction per kilogram
    • Gasoline: 12200 * 0.3 (efficiency) = 3660 watt-hours traction per kilogram.
    This is breakthrough territory.
  • by eth1 (94901) on Wednesday December 19, 2007 @02:47PM (#21755174)
    There are still a few problems, though.

    The first is heat from charging. If you use your figure of 900MJ, and charging is 90% efficient, that means you have to dissipate 90MJ of heat during the charge. 1J = 1Ws, so 90MJ is 25kWh of heat energy. That's 1kW if charging takes one day, or 4kW if it takes 6 hours. That's probably way too much heat for the battery/car to take. (assuming my math/conversions are correct!) Of course, that only applies if you're charging all at once. Charge time wouldn't be as much of an issue if you charge whenever you're not using the car.

    The other issue is that we (US) have nowhere near the generation capacity to handle a nation full of electric cars. We'd have to start building a lot of extra capacity, seeing as how we sometimes have a hard time keeping up with demand as it is. On the other hand, everyone having a huge battery plugged into the grid could do a lot to help smooth out peak demand.
  • by rs79 (71822) <hostmaster@open-rsc.org> on Wednesday December 19, 2007 @04:22PM (#21756640) Homepage
    "Batteries might suck in comparison to gasoline"

    Ah yes but. In a car, an electric car, it had one property no gas power car can ever have - you can recharge it with sunlight. I work at home and I don't go on daily commutes. Some weeks I may go to the store a few times and that's it. A moderate solar array might in some cases eliminate or at least diminish the need to plug the car in and pay for electricty. There's a certain appeal to that that in some sense overrides all other desirable features in a car.

    Now if these batteries can take a 2 hour laptop and give you 20 hours from it, uh does that mean the Tesla roadster now can do 4000 miles instead of 400 miles? That would be kinda significant...
  • On that note... (Score:2, Insightful)

    by scarboni888 (1122993) on Wednesday December 19, 2007 @04:31PM (#21756780)
    where ARE my *rechargable* lithium AA, AAA, C, D, & 9 volt batteries? NiMH is an improvement over NiCD but given all the rechargable Li-ION & Li-Polymer batteries in cell phones, laptops, etc... what is the deal?

    **reaches for tin foil hat**

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