Scientists Use 'Super Iron' to Create Super Batteries

Thursday, August 12th 1999, 12:00 am
By: News On 6

WASHINGTON (AP) -- A new generation of batteries that could run
that pink bunny ragged may be on the horizon: They last 50 percent
longer than today's batteries, thanks to a "super-iron" component
that promises to be easy and affordable to manufacture.

They're still under development, so don't look for them in local
stores soon.

But researchers at the Israel Institute of Technology invented
super batteries that could run CD players and flashlights -- and say
the new batteries also could come in the rechargeable forms needed
to power camcorders, laptop computers, even electric cars.

"Improved batteries are needed," says Stuart Licht, a
chemistry professor who led the research team in trying a host of
materials, from sulfur to tin, before they discovered an unusual
form of iron boosts battery life.

"From the outside, the super-iron batteries look identical to
conventional" AA or AAA batteries, he said in an e-mail interview
from Haifa. "The difference is within, and in the much greater
energy generated by the super-iron battery."

The new batteries have 50 percent more energy than traditional
batteries, Licht reports in Friday's edition of the journal

When he tested gadgets that drain batteries at extra-high rates,
such as portable CD players, he found that the super iron also has
extra conductivity, leading to another advantage.

"A conventional AAA-size alkaline battery may last only a few
minutes at high-drain rate, but under the same conditions, a AAA
super-iron battery discharges for well over an hour," he said.

Battery experts called the discovery promising.

"It's a significant advance scientifically," said Jack
Winnick, a chemical engineer at the Georgia Institute of
Technology. "I think the manufacturers will be intrigued by it.
The market right now for these alkaline cells is so enormous ...
that if they could make a rapid replacement, I think they would."
But Licht declined comment when asked if manufacturers already
are interested in commercializing his invention.

Some 60 billion alkaline batteries -- the type most sold -- are
used worldwide each year. But their basic internal design hasn't
changed much since the late 19th century: They typically contain a
zinc anode and a manganese dioxide cathode.

Batteries convert chemical energy into electrical energy through
reactions at the anode and cathode. When active materials at either
electrode are used up, the battery dies. In most alkaline
batteries, the cathode dries up long before the anode.

So the scientists made a new cathode from "super iron," a
chemically unusual form called iron(VI) that scientists long
believed too unstable for batteries -- because if it came into
contact with liquids, it disintegrated into rust in minutes. But
Licht discovered that the caustic solutions commonly used inside
batteries actually stabilize the super iron so it doesn't decay.

The super iron absorbs more electrons than the old-fashioned
cathode, making it more powerful, Licht's team showed.

Industry -- and consumers -- are demanding longer-lasting
batteries for a variety of uses. Electric cars, for instance, have
been stalled by the quest for an affordable battery that can go
longer distances without frequent recharging.

Most such research has focused on lithium-based batteries, where
highly energetic but lighter-weight lithium compounds are used to
make anodes, said Georgia Tech's Winnick.

But lithium is much more scarce than iron and a hundred times
more expensive, Licht said.

There are still questions about the new batteries that require
further testing, such as how long a shelf life they will have.

Still, if the batteries ultimately are sold, disposing of used
ones will cause a little less environmental damage than today's
batteries because the super-iron eventually just rusts, Licht said.

(Copyright 1999 by The Associated Press. All Rights Reserved.)