November 30, 2006 10:40 AM PST
Revving up for the all-electric SUV
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Just as important, it can be completely recharged out of a wall socket and a 220-watt adapter in about 6 to 7 hours, or through a special charger in about 10 to 15 minutes.
Phoenix will then follow the truck up with a sport-utility vehicle (SUV) that can go 250 miles on a single charge. Pricing should be about the same.
At the heart of these cars is a lithium-ion battery from Altair. Until recently, lithium batteries have been considered too unstable and volatile for use in cars. Put simply, lithium batteries can blow up and the bigger the battery, the larger the potential explosion.
Altair says its NanoSafe battery throttles that problem because the anode--the component inside batteries that discharges electrons--is made from lithium titanate spinels, a particle made from two lithium atoms, three oxygens and a titanium atom. Conventional anodes are made from graphite. Graphite flakes can come loose and can react with the electrolyte, the liquid carrying the lithium particles, and start a thermal runaway reaction. By contrast, Altair's anode is inert.
"It won't interact with the electrolyte," said Altair CEO Alan Gotcher. "We haven't had a single failure of a cell in any safety tests and that includes putting a nail through the cell and overcharging it."
Besides Phoenix, the U.S. Navy is experimenting with Altair's battery in an effort to make a mobile 1-megawatt power station that can be mounted on a ship.
Lithium-ion technology appears to be entering a radically new phase. Stung by a string of recalls, notebook makers are beginning to look more closely at alternatives, such as zinc-based batteries.
But electric car proponents say that the performance advantages, when combined with improved safety techniques, make the technology ideal for their markets. Tesla Motors has made a sports car that can go from 0 to 60 miles per hour in 4 seconds on a 6,800-cell lithium battery. To tame the potential explosive problems, Tesla isolates each lithium battery cell from one other to prevent chain reactions. While the sports car will sell for around $90,000 when it comes out next year, a mid-size sedan in the $50,000 range will come out in three or so years.
Valence Technologies, meanwhile, has experimented with changing the cathode. The electrons from the anode get attracted to the cathode and, during the journey, power devices such as lightbulbs.
Scientists in the past have tried to develop titanate spinel anode batteries. Unfortunately, the active particles on those early batteries were too large. By decreasing the size of the particles to a few nanometers, Altair can increase the size of the chemically active surface area on the anode. That leads to more simultaneous chemical reactions and more energy delivery. Gotcher likens the structure of Altair's anode to a cluster of grapes, or sugar crystals on the surface of a cookie.
"Others looked at this with 5- to 10-micron (diameter) particles and it was a dog," he said. As a result, electric cars like the Zap car mostly have used standard lead acid batteries. Zap cars top out at 35 miles per hour.