Ultracapacitors

Discussion in 'Gen 2 Prius Technical Discussion' started by skruse, Sep 3, 2007.

  1. skruse

    skruse Senior Member

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    http://www.sfgate.com/cgi-bin/article.cgi?.../f141205D04.DTL

    Millions of inventions pass quietly through the U.S. patent office each year. Patent No. 7,033,406 did, too, until energy insiders spotted six words in the filing that sounded like a death knell for the internal combustion engine. An Austin-based startup called EEStor promised "technologies for replacement of electrochemical batteries," meaning a motorist could plug in a car for five minutes and drive 500 miles roundtrip between Dallas and Houston without gasoline.

    ZENN Motor pays EEStor for passing milestones in the production process, and chemical researchers say the strength and functionality of this material is the only thing standing between EEStor and the holy grail of energy-storage technology.

    Joseph Perry and the other researchers he oversees at Georgia Tech have used the same material to double the amount of energy a capacitor can hold. Perry says EEstor seems to be claiming an improvement of more than 400-fold, yet increasing a capacitor's retention ability often results in decreased strength of the materials.

    "They're not saying a lot about how they're making these things," Perry said. "With these materials (described in the patent), that is a challenging process to carry out in a defect-free fashion."
    Perry is not alone in his doubts. An ultracapacitor industry leader, Maxwell Technologies Inc., has kept a wary eye on EEStor's claims and offers a laundry list of things that could go wrong.

    Among other things, the ultracapacitors described in EEStor's patent operate at extremely high voltage, 10 times greater than those Maxwell manufactures, and won't work with regular wall outlets, said Maxwell spokesman Mike Sund. He said capacitors could crack while bouncing down the road, or slowly discharge after a dayslong stint in the airport parking lot, leaving the driver stranded.

    Until EEStor produces a final product, Perry said he joins energy professionals and enthusiasts alike in waiting to see if the company can own up to its six-word promise and banish the battery to recycling bins around the world.

    "I am skeptical but I'd be very happy to be proved wrong," Perry said.
     
  2. donee

    donee New Member

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    Hi Skruse,

    Besides those issues, the ferro-electric dielectrics used by EE-Stor tend to be very temperature sensative at the highest compounded dielectric constants. For example Z5U Dielectric reduces in capacitance to 44 % of the original in a temp change from 25 to 125 C. What does that mean? Well since Q=CV, or V=Q/C, and Q is not going to change during a temp shift on a parked car, it means V will go up. Which is just like asking for an explosion when you have that much power in such a small place. Ask they guy who pulled the switch on the first cyclotron coil. Ooops, no you can't, he was vaporized, litterally! Same thing only with Capacitors instead of a large coil with current flowing.
     
  3. qbee42

    qbee42 My other car is a boat

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    <div class='quotetop'>QUOTE(donee @ Sep 3 2007, 08:40 PM) [snapback]506519[/snapback]</div>
    Maybe we need to put two antennas on top of each car and make them into Jacob's ladders. :)

    Tom