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Nanowires Boost Laptop Battery Life to 20 Hours

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."

8 of 238 comments (clear)

  1. Sony Nanowire Batteries by Apple+Acolyte · · Score: 5, Funny

    Now with 10 times the explosive power.

    --
    Part of the hardcore faithful who believed in Apple long before it was cool again to do so
    1. Re:Sony Nanowire Batteries by mpe · · Score: 5, Funny

      Now with 10 times the explosive power.

      How long before laptop batteries get classified as "munitions"?

    2. Re:Sony Nanowire Batteries by Hal_Porter · · Score: 5, Informative

      How does the power density of these compare to gasoline? Lousy

      http://wiki.xtronics.com/index.php/Energy_density

      Material Volumetric(Wh/l)Gravimetric (Wh/kg)

      Fission of U-235 4.7 x 1012 2.5 x1010
      Boron 38,278 16361
      JP10 (dicyclopentadiene)10,975 11,694
      Diesel 10,942 13,762
      Gasoline 9,700 12,200
      Black Coal solid =>CO2 9444 6667
      LNG 7,216 12,100
      Propane (liquid) 7,500 - 6,600 13,900
      Black Coal Bulk =>CO2 6278 6667
      Ethanol 6,100 7,850
      Methanol 4,600 6,400
      Liquid H2 2,600 39,000
      Secondary LiOn Polymer 300 130 - 1200
      Secondary Lithium-Ion 300 110
      Nickel Metal Hydride 100 Wh/l 60Wh/kg
      Lead Acid Battery 40 25
      Propane (Gas - 1 bar) 28.1 13,900
      Compressed Air 17 34
      Ice to water 9.3 9.3

      If this new battery is 10x as efficient it is still 3x worse than gasoline.
      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    3. Re:Sony Nanowire Batteries by OwnedByTwoCats · · Score: 5, Insightful

      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.
  2. Smaller lighter batteries by farnsaw · · Score: 5, Insightful

    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.

    --
    "Computer Scientists can count to 1024 on their fingers" (non-mutant, non-mutilatated, human computer scientists)
  3. Re:Promising by TheRaven64 · · Score: 5, Informative

    It's not exactly a memory effect, but LiIon batteries do degrade over time. Unlike NiCd cells, their life is best preserved by keeping them about around 50% charge. You get a lot of people complaining that their batteries wear out quickly because they still think the things they learned about NiCd cells apply, so they fully discharge and recharge their LiIon cells, which is the absolute worst case for them.

    --
    I am TheRaven on Soylent News
  4. Re:Critical questions of how by quickpick · · Score: 5, Funny

    1) How much will they cost
    If you have to ask you can't afford it.
    2) How long does it take to charge
    Not too long, plug it in and wait for the amber light to turn green.
    3) How many charges can you get in its lifetime.
    If its made by Apple you can charge it as many times as you want, but replacing it will cost about 82% of the original cost of the full price of the original device you bought it for UNLESS you buy an Apple Care Plan for 73% of the full price of the original device you bought it for.

    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. They will ALL be deficient to one person or another...therefore the technology will be worthless in some aspect by someone. Why is it that people only want to use it in electric cars? I'm sure all the single and lonely women wouldn't mind having a device that doesn't quit on them before they're TRULY satisfied...which will never happen because women are never satisfied. Thats why its called a ball and chain.

    My money is still on ultra-capacitors.
    You fool. My money is in Gold because the Fiat System will fail at some point and you can't buy food with ultra-capacitors...

  5. I'm amped just reading this... by Akardam · · Score: 5, Funny

    The current limitation is that you cannot releaste the energy in a short burst.
    Yes, precisely!