Nanotechnology improving energy options

By CHARLES CHOI, United Press International

NEW YORK, May 24 (UPI) -- Nanotechnology could help revolutionize the energy industry, producing advances such as solar power cells made of plastics to environmentally friendly batteries that detoxify themselves, experts told United Press International.

Nanotechnology deals with tools at the level of atoms and molecules, on the scale of nanometers, or billionths of a meter. Because nanomaterials have far more surface area for chemical reactions or storage, they can become super-catalysts. Electrical and thermal properties and strength of materials also can improve dramatically.


One nanotech firm, mPhase Technologies in Norwalk, Conn., is partnering with Lucent Technologies to commercialize nanotechnology by creating intelligent batteries, with the intent of bringing the devices to the marketplace within the next 12 to 18 months.

"We were looking at how to take existing batteries, using chemicals and chemistry, and improve them using nanotechnologies," Steve Simon, mPhase executive vice president for engineering, research and development told attendees at a recent nanotechnology business conference in New York.


Batteries consist of metal electrodes that sit in chemicals known as electrolytes. When a battery is activated, the electrolytes react, with electrons streaming through the electrodes. Over time, the electrolytes react anyway, which is why batteries suffer from power drain even when not in use.

"Science suggests if you can separate the electrolytes from the metal part of the battery, it could last for a very long time -- very long shelf lives," Simon said.

Normal batteries also suffer from the fact that they are incompatible with semiconductor processing, which means they cannot be integrated with chips. They also are relatively slow in powering up, Simon added.

The company is seeking to develop a battery containing millions of silicon nanotube electrodes, sitting upright like a bed of nails. Atop each nanotube sits a droplet of electrolyte. The droplets rest atop the nanotubes without interacting, much like an Indian fakir can rest atop a nail bed. But when a voltage change pushes the droplets down into the spaces between the tubes, they react, causing current to flow.

"This can give them a very long storage life of years and years, by only activating when in use," Simon explained. The silicon-based devices are compatible with semiconductor processes, are easy to miniaturize, have a quick ramp up to full power, are inexpensive to mass produce and have high power and energy density.


The nanobatteries also can contain droplets that can neutralize the often-toxic electrolytes when it comes time to dispose of them. "This green effect means when thrown away, it does not pollute the environment," Simon said.

Another potential energy application involves powders of nanoparticles that can serve as fuel additives and catalysts for energy recovery, Randy Bell, president and CEO of Nanotechnologies, a company in Austin, Texas.

"Our fuel cells use nano-aluminum, and are highly energetic, producing hydrogen when put in water," Bell said. The aluminum produces more rapid and efficient burning than other existing powders, rendering it of interest for applications in rocket fuels, high-energy explosives and lead-free gun primers.

Konarka Technologies of Lowell, Mass., makes plastic devices that absorb sunlight and indoor light and convert them into electrical energy.

The devices resemble gift-wrapping paper in their thinness and flexibility, and can be integrated into fabrics and roofs. They are made using nanoscale titanium dioxide particles coated in photovoltaic dyes. When light hits the dye, they generate electricity.

"They're lightweight and flexible, more versatile than previous generations of solar cells," said Daniel McGahn, Konarka's executive vice president and chief marketing officer.

Investors in the technology include Electricité de France and ChevronTexaco, respectively the first and fifth largest energy companies in the world.


"We can get to the point where the initial cost can be competitive with the electric grid," McGahn told UPI. "If we had a 10-mile-by-10-mile square, we could power the country."

Traditionally, solar power cells are built of crystalline silicon or glass. "Coating them on plastic is fundamentally different from silicon-based semiconductors. Ours is inherently low cost," McGahn said, adding that Konarka already has sold the devices to the military for use on tents.

"You look at a soldier today. A regular field soldier carries 1.5 pounds of batteries now. A special operations soldier has a longer time out, has to carry 140 pounds of equipment besides his or her body mass, 60 to 70 pounds of which are batteries," McGahn said. "So we hope to come down on that weight."

Another energy technology that could shrink a soldier's battery load comes from Nanodynamics in Buffalo, N.Y. The company manufactures a 50-watt, solid oxide fuel cell roughly the size of a loaf of bread that can generate 3,000 watt-hours of electricity from just five pounds of propane fuel. A conventional solid oxide fuel cell given that amount of propane would generate only one-half to one-third as many watt-hours.

"We can think of replacing about 80 percent of the batteries a soldier carries with a cylinder of fuel, and literally give them months and months of operating time without recharging or getting to base camp," said Keith Blakely, CEO of Nanodynamics. He said the device basically takes conventional fuel cell components and miniaturizes them, using nanosized powders, microtubules and nanocoatings.


"It's to be launched later this year," Blakely said.


Charles Choi covers research for UPI Science News. E-mail [email protected]

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