Smaller Is Better

David Vieau, A123Systems' CEO and president, is anxious to expand markets for the nanophosphate technology and says the company is actively talking with cell phone companies--Motorola and Qualcomm are investors--and also is engaged in a project related to hybrid automobiles. But a move into notebook computers looks years away.

In addition to the benefits of phosphate, A123Systems' nanoscale approach reduces the size of individual particles in the battery from an average of 1 micron or larger in conventional lithium-ion technology to 100 nanometers, or about 1/100th the size. Smaller particles can absorb lithium at a greater rate than regular batteries, which lets the battery recharge more quickly. An average charge time of two to three hours for a cell phone could be reduced to five to 10 minutes, Vieau says. And while a typical cell phone battery provides 300 to 400 charge cycles in a lifetime, the A123Systems technology promises 7,000.

Battery companies are trying a wide variety of chemical formulas to find one that duplicates or bests lithium ion. Ross Dueber, president and CEO of Zinc Matrix Power, believes his alternate-chemistry battery will be ready for commercial deployment next year. Intel, which has invested in Zinc Matrix, named the company the winner of the Technology Innovation Accelerated Award for the mobile category at the Intel Developer Forum in September.

The Zinc Matrix approach uses silver and zinc to provide as much as twice the running time of lithium ion, and its water-based chemistry isn't flammable or toxic, Dueber says. The company initially concentrated on military applications, but after receiving investment from Intel two years ago, turned its attention to creating a notebook battery that runs up to 10 hours.

But it has too big a trade-off right now. Dueber says he can create batteries that are about 20% denser in energy than lithium ion, increasing to 50% greater energy density as he ramps up production. But they only last for about 25 recharges, compared with 200 to 250 for today's batteries. The company is working toward around 100 recharges, which, with the longer per-charge life of the zinc-based battery, would move it into the league of lithium ion in total usable life.

"When lithium ion started out about 15 years ago, it could provide about half the cycle life of the nickel metal hydride it was replacing, but it also offered a 30% improvement in runtime, so that was a trade-off consumers were willing to make," he says.

Zinc Matrix plans to work with notebook and cell phone manufacturers to get new designs ready for production next year. Initially, the technology would likely be marketed as a higher-end option for devices such as "road warrior laptops," Dueber says.

History suggests what shows up in high-end equipment will quickly make its way into mainstream gear--if it can be manufactured in large quantities at low cost. That's the challenge: to economically produce a power source that can handle the various needs of the computer, cell phone, and consumer electronic industries, which require billions of batteries each year.

Hopefully, Sony can put an end to the burning laptop problem. But even then, it's looking for the next few years like businesses and consumers will have to live with various performance trade-offs as they wait for the long-lived battery of their dreams.

Photo by MIT