06/01/93
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STANFORD - The future of the electric automobile depends on the development of a practical battery with a useful range, something that has so far eluded engineers. A new battery, using nickel metal hydride may be the answer.
"This is a new battery, which is non-toxic, environmentally green and requires no maintenance," said Stanford chemistry professor John Ross, who created the battery with Energy Conversion Devices, a Michigan-based company.
The development was reported in a recent issue of Science magazine. Ross served as consultant and was co-author of the paper.
The nickel metal hydride battery satisfies almost all the requirements for an intermediate battery for electric vehicles set by the U.S. Advanced Battery Consortium, a Department of Energy-headed group, consisting of Chrysler, Ford, General Motors and the Electric Power Research Institute, which supports research and development of batteries for electric cars.
Electric vehicles have been impractical because their range has been limited by existing batteries - lead acid batteries could only run about 120 miles before needing to be recharged.
The nickel metal hydride battery, however, more than doubles that.
"At a single charge, it [the new battery] can go about 250 to 300 miles," Ross said.
And it can be fully charged in less than an hour, much less than the time required by conventional batteries.
"The quickest charging time is about 20 minutes," Ross said, "but that takes quite a bit of current. You wouldn't want to do that in your house but, on the other hand, if you drive during the day and come home at night, you can recharge it during the night."
The battery uses a proprietary mixture of nine or 10 metals to store hydrogen as a solid. When the battery is being operated, it discharges the hydrogen; it stores hydrogen when charging. The chemical process involves nickel hydroxide and nickel oxyhydroxide.
The new battery, which normally holds 1.2 volts, could cost around $200 per kilowatt hour, compared to just under $150 for present batteries. It could last 10 years as opposed to only five for the conventional device.
A switch to electric vehicles would serve the United States by reducing both pollution and dependence on oil imports, Ross said. "The benefits of electric cars are first of all environmental," he said. "They're emission- free."
By decreasing the demand for gasoline, electric cars also would help the U.S. balance of trade by cutting down substantially on imported oil.
"If the United States switches away from gasoline to electricity, we're switching from oil to coal, natural gas and hydro power," Ross said. "That means you're switching away from importing oil. Right now, we're importing about $65 billion dollars [of oil] a year, and our trade imbalance is $90 billion, so oil is a substantial part of the trade imbalance that is slowly making us bankrupt."
Although use of electric cars will require an increase in coal- burning to generate more electricity, the general environmental effect will be positive, Ross said.
"In a coal-fired plant," he said, "you can control pollution much better than you can emissions from an automobile."
Coal "pollutes significantly less than oil usage in a car," he said.
The battery is currently being tested by American, European and Japanese manufacturers, including Honda, the Japanese car company, and Varta, the largest battery manufacturer in Europe.
Ross expects that car companies will soon have electric vehicles ready to test the new battery and believes that the actual electric car may be available as soon as next year.
"The Americans are planning for 1995," said Ross. "The Japanese may be coming out [with an electric car] next year."
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This story was written by Emmeline Chen, a science writing intern at the Stanford News Service.
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