When Energy Rhymes With Nanotechnology

By Roland Piquepaille

Let's face it. Our computing devices are going faster year after year. But our laptop batteries don't show the same performance improvement. They still work only for a few hours, just a little bit more than ten years ago. Several companies want to change this, according to this UPI report, "Nanotechnology improving energy options." For example, mPhase Technologies plans to introduce smart batteries based on millions of silicon nanotube electrodes. These nanobatteries, to be introduced before the end of 2005, will last longer than traditional ones and will be respectful of our environment. Meanwhile, Konarka Technologies wants to reduce the weight of batteries with its flexible solar-fueled nanobatteries.

Let's start with the new battery nanotechnology from mPhase Technologies.

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.

		The droplet sits above the nanotubes with little or no interaction with the tubes themselves. But when it falls within the space between the tubes, they encounter a greatly increased surface area and interact with the tubes themselves, causing current to flow (Credit: mPhase Technologies).

"This can give them a very long storage life of years and years, by only activating when in use," explained Steve Simon, mPhase executive vice president for R&D. 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.

Improving batteries performance is a good thing. Reducing their weight is another one. Do you know that special operations soldiers on battlefields can carry up to 70 pounds of batteries, or half of the weight of the quipment they have to bear? Konarka Technologies wants to reduce this.

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.

As you can see below, these photovoltaic materials can be incorporated into a wide range of products (Credit: Konarka Technologies).

"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.

According to UPI, this company has serious backers, such as Electricité de France and ChevronTexaco.

For more information, the UPI report mentions other companies involved in batteries using nanotehnologies.

Sources: United Press International, May 24, 2004; and various websites