Re: Can anything tame the battery flames?

Need for Battery Power Runs Into Basic Hurdles of Science

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By DAMON DARLIN and BARNABY J. FEDER
Published: August 16, 2006
It always seems to happen: Long before it is time to stow your tray
table, your laptop battery gives out, and you spend the rest of your
cross-country trip reading the SkyMall catalog.

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Scientists are having trouble creating long-lasting, safe batteries.
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In the information age, people want their electronics everywhere they
go, and they want them to be on all the time. But they rely on
batteries that have not improved as rapidly as the devices they power.
Moore's Law, which offers a yardstick for the exponential advances in
computer chips, has no counterpart in the world of batteries.

Researchers are certainly trying to improve the situation, in part
because there is money to be made. Portable rechargeable batteries are
expected to be a $6.2 billion market this year, and more than one
billion batteries will be made by some of the largest electronics
companies in the world: Sony, Sanyo, Matsushita and Samsung.

But scientists are running into some basic hurdles of chemistry and
physics. The more energy they store in a small package, the more
volatile and dangerous that package becomes.

The volatility of batteries in laptops, and those powering millions of
portable consumer devices from cellphones to power drills, was made
apparent Monday with Dell's recall of 4.1 million laptop batteries.
Dell said the batteries, made by Sony, could catch fire because of a
problem in the manufacturing process.

Though the chance of a flaming notebook is small, the number of
incidents involving burning batteries is rising each year because there
are so many more devices using small and powerful power sources.

There is another pressing reason for the quest for improvements:
battery-powered cars. An electric car needs a power source that is
2,000 times as powerful as a laptop battery. "That size would be
extremely dangerous," said Sanjeev Mukerjee, a chemistry and chemical
biology professor at Northeastern University. "This technology has a
downside, and that is that it is very sensitive to how it is
manufactured."

The potential for fire in a lithium-ion battery is a result of its
chemical composition. Contained in that small package are all the
elements needed for a fierce blaze: carbon, oxygen and a flammable
fluid. The battery is made of a thin layer of lithium cobalt oxide,
which serves as the cathode, and a strip of graphite, the anode. These
are separated by a porous insulator and surrounded by fluid, a lithium
salt electrolyte that happens to be highly flammable.

When the battery is charged, lithium ions on the cathode migrate to the
anode. As the battery is used, the ions migrate back to provide the
energy. In the charged state, the cathode without most of its ions is
highly unstable. If a spark occurs, the temperature of the cathode can
exceed 275 degrees.

That is hot enough to cause the cathode to decompose and release
oxygen. A fire starts, and as heat builds the battery begins what
scientists call a "thermal runaway." In the case of the Sony-made
batteries recalled by Dell, a microscopic metal particle that
contaminated the electrolyte during manufacturing caused the spark.

Scientists are looking for new battery chemistry that does not involve
carbon, oxygen and fuel. One route is to make an electrolyte that is
not flammable, said Jai Prakash, associate professor of chemical
engineering at the Illinois Institute of Technology. But much of the
work is concentrated on replacing the cobalt-based cathode with
magnesium. Others want to get the carbon out of the system. Sony, for
instance, has a new generation of batteries that use tin.

Valence Technology, a maker of alternatives to lithium-ion batteries in
Austin, Tex., uses a phosphate-based cathode. "Consumers do a lot of
bad things to battery packs," said James R. Akridge, Valence's
chief executive. "These provide an extra measure of safety if they
shake it or smack it."

Valence products are used in Segway scooters and hospital diagnostic
equipment. But the company has no intentions of competing against the
large lithium-ion battery makers in the market for consumer devices.
Mr. Akridge said the big companies dominate because they compete on
price, and "price is determined by scale."

As consumers demand more from notebooks and cellphones, the electronics
industry may need a whole new way of thinking about power supplies. The
most likely candidates are miniaturized versions of the fuel cells that
are being developed for cars. Fuel cells use hydrogen, but because
hydrogen is hard to store and handle, many microcells get hydrogen from
fuels like methanol.

Microcells intrigue companies that make laptops, cellphones and other
portable devices because they can store far more energy than comparably
sized batteries. Methanol-based microcells, for instance, have roughly
10 times the energy density, creating the prospect of wireless laptops
that could run all day without recharging, according to Rick Cooper,
vice president for business development of PolyFuel Inc. The company,
based in Mountain View, Calif., supplies components to several Asian
manufacturers that have been working on such devices.

"The energy capacity of batteries is increasing 5 percent to 8
percent annually, but demand is increasing exponentially," Mr. Cooper
said.

The tweaking of materials and chemicals in the lithium-ion battery will
extend its usefulness for at least another decade or more, said Gao
Liu, a scientist at Lawrence Berkeley National Laboratory. He expects
innovation to come slowly.

"We don't see any new energy storage devices," Mr. Liu said. The
best bet for the future is probably fuel cells, he said, but it may be
more than a decade before they start appearing in mass-market portable
devices.

Microcells have been just over the industry's horizon since Toshiba
demonstrated a prototype at a trade show in 2003. Pulling together all
of the components has proved more challenging than fuel cell advocates
predicted.

Manufacturers of fuel cells have been looking to the military and niche
markets like users of professional video cameras as their first
customers.

Nanotechnology, the fast-developing field that involves manipulating
materials at scales measured in billionths of a meter, is likely to
play a significant role in the future of consumer batteries. One
essential for further development of current battery designs is the
ability to cram more energy into today's packaging. Nanoscale
processes could be used to make the surfaces of electrodes more porous,
creating a larger surface area for chemical reactions.

Nanotechnology could also help improve the performance of competing
technology like fuel cells. "Designer" molecules and films that
could act as improved catalysts in fuel cells are a hot research area.

But to some nanotechnology companies, consumer batteries are too
competitive to be a high priority. Altair Nanotechnologies, based in
Reno, Nev., claims that its technology has safety advantages over
lithium-ion batteries, but Altair executives say the difference would
not be enough to win over makers of laptops and cellphones. Nor could
Altair compete on cost.

"If you go into laptops, you are competing with well-entrenched
companies that make millions of batteries and have been doing it for
years," said Alan J. Gotcher, Altair's chief executive.
http://www.nytimes.com/2006/08/16/technology/16battery.html?_r=1&oref=slogin

lkgeo1 wrote:
Need for Battery Power Runs Into Basic Hurdles of Science
New York Times - United States
... The most likely candidates are miniaturized versions of the fuel
cells that are being developed for cars. Fuel cells use hydrogen ...
Trailer Trash wrote:
Check out MKTY

I think they have the best chance in replacing cheap "Chinese" Lithium
Ion batteries.

I hope they can keep their FAA approval after what happened in Great
Britain.


nikverse@xxxxxxxxxxxxxxxxxxxx (Charlie Perrin)

On Wed, 16 Aug 2006 00:54:21 GMT, Don S wrote: If you think exploding
laptops are a problem now, wait until they try to put hydrogen furl
cells into them, remember Apollo 13 that was a fuel cell that exploded
on it.

On Apollo 13, one of the oxygen tanks exploded.

The fuel cells continued to work until all the oxygen escaped.

.

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