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Capacitors to Replace Batteries?

Posted by ryuzaki0 on from the going-and-going-and-going dept.

An anonymous reader writes "MIT's Joel Schindall plans to use old technology in a new way with nanotubes. 'We made the connection that perhaps we could take an old product, a capacitor, and use a new technology, nanotechnology, to make that old product in a new way.' Capacitors contain energy as an electric field of charged particles created by two metal electrodes, and capacitors charge faster and last longer than normal batteries, but the problem is that storage capacity is proportional to the surface area of the battery's electrodes. MIT researchers solved this by covering the electrodes with millions of nanotubes. 'It's better for the environment, because it allows the user to not worry about replacing his battery,' he says. 'It can be discharged and charged hundreds of thousands of times, essentially lasting longer than the life of the equipment with which it is associated.'"

3 of 499 comments (clear)

  1. Re:Not sure how this works by tygerstripes · · Score: 5, Interesting

    Good point. Maybe the nanotubes actually mesh between each other - kind of like the teeth in gears. Can't see it being easy to manufacture, but that would definitely provide a massive increase in closest-point surface area.

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  2. A good electric Car. by jellomizer · · Score: 5, Interesting

    With its longer life and faster recharge time. I wonder if this could lead to an electric car that is good for the masses where they can cross country and take only 5 to 10 minutes to recharge. That is the primary reason why the Electric Car never made popularity it is because it is not convenient enough for normal people.

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  3. Re:Not sure how this works by TeknoHog · · Score: 5, Interesting

    In electrolytic capacitors, one electrode is formed by a conducting liquid, and an oxide layer on the metallic conductor acts as the insulator. The nanotube version may use something like this.

    On another note, every time someone proposes to replace batteries with capacitors, I wonder how they make up for the huge variation of voltage that a capacitor delivers. Basically, the voltage of a capacitor is proportional to the amount of charge stored, whereas a battery provides more or less constant voltage. The capacitor-battery would require a circuit (something like a switching power supply) to be able to provide constant voltage. That, in turn, would take up space and waste some energy.

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