Battery breakthrough, or just hot air?

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Previous attempts to improve ultracapacitors have focused on improving the metal sheets by increasing the surface area where charges can attach.

EEStor is instead creating better nonconductive material for use between the metal sheets, using a chemical compound called barium titanate. The question is whether the company can mass-produce it.

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.

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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.”

Potential problems
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.

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