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Thursday, March 01, 2007

A Battery Beyond Belief?

A secret, fast-charging, powerful battery.

By Tyler Hamilton

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The first peek at a much-hyped new battery technology will come courtesy of electric cars made by Zenn Motor of Toronto.
Credit: Zenn Motor

Is EEStor of Cedar Park, TX, for real? The secretive company announced earlier this year that it plans to begin shipping a 15-­kilowatt-hour electrical-energy ­storage system that can propel a small electric car 322 kilometers and takes just minutes to charge.

The first customer: Toronto-based Zenn Motor, which makes electric vehicles. EEStor says its technology is a cross between a battery and an ultracapacitor (which quickly stores and releases energy) and is based on mysterious ­barium ­titanate powders.

Company documents claim that the new storage system has better energy density than lithium-ion and nickel-metal hydride batteries, that it charges more quickly, and that it's cheaper and safer. The implications are enormous and, for many, unbelievable, but the company says it's all true. "We're well on our way to doing everything we said," says ­Richard Weir, EEStor's cofounder and chief execu­tive.

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March/April 2007

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Comments

  • EEStor hype
    Emosson on 03/12/2007 at 12:44 AM
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    2
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    3/5
    I repeat my comment from January 22, 2007 at http://www.technologyreview.com/read_article.aspx?id=18086&ch=biztech

    Unfortunately EEStor never made and will never make the supercapacitor described in the patent

    http://www.google.com/patents?vid=USPAT7033406&id=cjx3AAAAEBAJ&printsec=abstract&zoom=4&dq=eestor#PPA3,M1)

    because they ignore a well known physical effect, called “dielectric saturation”.

    Barium titanate has been used in capacitors for decades, due to its high dielectric constant:

    http://www.avxcorp.com/docs/techinfo/mlcmat.pdf

    However, the dielectric constant drops as the electric field strength increases:

    http://www.nap.edu/books/NI000488/html/49.html
    http://prola.aps.org/abstract/PR/v71/i12/p890_1

    At a hypothetical field of 3500 Volts over a thickness of 12.76 micrometers, as proposed in the patent, the dielectric constant of barium titanate would be orders of magnitude lower than the claimed 18500, reducing capacity and energy density by the same factor…

    This has been discussed in more detail by Anatoly Moskalev on December 24th and 26th, 2006 in
    http://www.teslamotors.com/blog1/index.php?p=43

    with an update on January 20th, 2007:
    http://www.teslamotors.com/blog1/?p=46
    Rate this comment: 12345
  • What New?
    rhapsodyinglue on 03/12/2007 at 5:54 PM
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    4/5
    Why is there a second article so close to the one in January about EEStor?  Doesn't seem there is anything new or newsworthy in this latest article.  Is TechnologyReview or Tyler Hamilton compensated for PR in some way?

    Would love to read some real journalism about this new technology but not just rehash quoting company documents.
    Rate this comment: 12345
  • I'm glad for the updates
    asdar on 03/19/2007 at 4:35 PM
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    5/5
    I'm glad for the updates on EESTOR and I hope they keep coming for good or bad.

    EESTOR employees and businessmen have all read the critics comments and the professional scoffers, and yet they still say they're going to deliver the product and that it'll do all that they say.

    If you quadruple all the bad and quarter all the good stats it's still an industry making discovery. The CEO saying at this late stage that they will deliver this year is  significant in my opinion.

    We'll know in less than 9 months time, that's such a short time that you scoffers won't even get to build up to a good I told you so.
    Rate this comment: 12345
  • Very interesting.
    cobraphx on 01/22/2008 at 5:40 PM
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    13
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    5/5
    If you read the posts on here from the last EEstor article, it would seem that Lockheed also has physicists that can't do the math as EEstor and Zenn. Somehow I think Lockheed isn't getting the wool pulled over it's eyes in this venture.

    It was previously stated be several times in the last thread that EEStor made a common mistake in calculating permittivity, like this one:

    "I checked it myself to find the two classical, almost high-school-type physical mistakes:

    [1] Assumption of linear permittivity for high fields, which is not true for high-permittivity insulators, in particular, this Barium Titanate powder.
    [2] The alleged 12% reduction in permittivity due to the coating. "

    Seems the engineers and physicists that Lockheed Martin talked to made the same high school physics mistakes. Maybe they just took EEStor's word for it and said, "whatever you say, looks good to us we'll take a chance". Or could it be that EEStor showed them some evidence to back up their claims? It just seems more likely that we'll see something come of this.

    Plenty of people around here said that Nanosolar was just a sham. Nanosolar certainly still has a few things to prove, but I'm pretty sure they are for real. Seems EEStor may have followed the same "leave us alone while we get this to work" business style.

    Then again, maybe they will flop. Either way, it keeps things interesting.
    Rate this comment: 12345
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