Monday, January 22, 2007

Battery Breakthrough?

A Texas company says it can make a new ultracapacitor power system to replace the electrochemical batteries in everything from cars to laptops.

By Tyler Hamilton

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The ZENN car will be the first commercial application of EEStor's new energy storage system. The company is expecting delivery of the systems later this year.
Credit: ZENN Cars

A secretive Texas startup developing what some are calling a "game changing" energy-storage technology broke its silence this week. It announced that it has reached two production milestones and is on track to ship systems this year for use in electric vehicles.

EEStor's ambitious goal, according to patent documents, is to "replace the electrochemical battery" in almost every application, from hybrid-electric and pure-electric vehicles to laptop computers to utility-scale electricity storage.

The company boldly claims that its system, a kind of battery-ultracapacitor hybrid based on barium-titanate powders, will dramatically outperform the best lithium-ion batteries on the market in terms of energy density, price, charge time, and safety. Pound for pound, it will also pack 10 times the punch of lead-acid batteries at half the cost and without the need for toxic materials or chemicals, according to the company.

The implications are enormous and, for many, unbelievable. Such a breakthrough has the potential to radically transform a transportation sector already flirting with an electric renaissance, improve the performance of intermittent energy sources such as wind and sun, and increase the efficiency and stability of power grids--all while fulfilling an oil-addicted America's quest for energy security.

The breakthrough could also pose a threat to next-generation lithium-ion makers such as Watertown, MA-based A123Systems, which is working on a plug-in hybrid storage system for General Motors, and Reno, NV-based Altair Nanotechnologies, a supplier to all-electric vehicle maker Phoenix Motorcars.

"I get a little skeptical when somebody thinks they've got a silver bullet for every application, because that's just not consistent with reality," says Andrew Burke, an expert on energy systems for transportation at University of California at Davis.

That said, Burke hopes to be proved wrong. "If [the] technology turns out to be better than I think, that doesn't make me sad: it makes me happy."

Richard Weir, EEStor's cofounder and chief executive, says he would prefer to keep a low profile and let the results of his company's innovation speak for themselves. "We're well on our way to doing everything we said," Weir told Technology Review in a rare interview. He has also worked as an electrical engineer at computing giant IBM and at Michigan-based automotive-systems leader TRW.

Much like capacitors, ultracapacitors store energy in an electrical field between two closely spaced conductors, or plates. When voltage is applied, an electric charge builds up on each plate.

Ultracapacitors have many advantages over traditional electrochemical batteries. Unlike batteries, "ultracaps" can completely absorb and release a charge at high rates and in a virtually endless cycle with little degradation.

Where they're weak, however, is with energy storage. Compared with lithium-ion batteries, high-end ultracapacitors on the market today store 25 times less energy per pound.

This is why ultracapacitors, with their ability to release quick jolts of electricity and to absorb this energy just as fast, are ideal today as a complement to batteries or fuel cells in electric-drive vehicles. The power burst that ultracaps provide can assist with stop-start acceleration, and the energy is more efficiently recaptured through regenerative braking--an area in which ultracap maker Maxwell Technologies has seen significant results.

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Battery Breakthrough?

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