ORNL's Battery Technology Gains More Recognition

ORNL's development of rechargeable thin-film lithium batteries continues to attract attention. The technology is being used in the Department of Energy's 1000th cooperative research and development agreement (CRADA), it received a prestigious DOE award, and the rights to commercialize it have been granted to Teledyne Electronic Technologies.

A Hazard Card, a badge that will warn workers of the presence of hazardous gases, is the expected product of DOE's 1000th CRADA. The electronically operated gas sensor will be powered by the award-winning thin-film lithium battery developed at ORNL.

The participants in the CRADA are Research International of Woodinville, Washington, and John Bates, Nancy Dudney, and Chris Luck, all of the Ceramic Thin Films Group that Bates heads in ORNL's Solid State Division. The group's development of rechargeable thin-film lithium batteries also received a Significant Implication for Department of Energy-Related Technologies Award in the Solid State Physics category in DOE's 1994 Materials Sciences Research Competition.

The 1000th DOE CRADA was signed in September 1994 in Washington, D.C. Present at the signing were Secretary of Energy Hazel O'Leary; Elric Saaski, president of Research International; and Alvin Trivelpiece, ORNL director. This agreement was one of 87 CRADAs signed in fiscal-year 1994 by Martin Marietta Energy Systems, Inc.

The goal of this CRADA is a credit-card-size device in which a gas sensor detects hazardous gases and special electronics warn the badge wearer of the presence of these gases through light and sound signals. The electronics would be powered by a rechargeable lithium microbattery half as thin as plastic wrap.

The lithium-vanadium oxide battery used for the Hazard Card is one of several types of thin-film rechargeable lithium batteries developed by the ORNL group. These solid-state batteries, which can be cycled thousands of times, can be fabricated in virtually any size and shape to meet the needs of a variety of electronic devices.

"For the Hazard Card," Bates says, "a battery measuring 9 square centimeters and 5 microns thick will supply the current required--between 2.5 and 3.5 volts--to operate the card continuously for more than 8 hours before recharging."

The ORNL battery can operate at higher voltages and currents than previously developed thin-film batteries. The key to this improvement was the group's discovery in 1991 of an effective solid electrolyte, called amorphous lithium phosphorus oxynitride, or Lipon. The electrolyte separates the reactive electrodes (the lithium and vanadium oxide film layers), enabling the conversion of the battery's chemical energy into electrical energy.

Bates' group participated in an earlier CRADA in 1992 with Eveready Battery Company. In this project the researchers developed a protective coating for thin-film lithium batteries.

Currently, the group is involved in a CRADA with Teledyne Electronic Technologies. Researchers are working to apply the sensing device first to the electroencephalogram (EEG), a test that monitors activity in the brain. The technology may later be applied to the electrocardiogram (EKG), a test for detecting abnormal activity in the heart.

In these tests, extremely low-level electric signals received from the body are relayed by sensors across electrical wires to a machine that amplifies the signal for a reading. "During that trip, motion and other environmental factors can distort and even swamp out the signal," says Bob Steenberge, a researcher at Teledyne. "The technology we're developing puts the amplifier right at the head of the source, making for a clearer signal, and the lithium battery may provide just the power source we need to operate it."

Several companies have shown interest in ORNL's thin-film lithium battery for these applications: backup power for computer memory chips in case of a power outage, backup power for solar-powered devices in space, notebook computers, miniature hearing aids, and ultrathin watches. Bates' group is also exploring the use of thin-film batteries for powering micromachines.

ORNL Sensor Research To Aid Traffic Flow for Atlanta Olympics

ORNL is involved in a CRADA with an Atlanta, Georgia, company to improve the traffic flow during the Summer Olympic Games to be held in 1996 in Atlanta. Steve Allison, David Howell, and Gary Capps, all of ORNL's Engineering Technology Division, will work with Supercond Technology, Inc., to develop a traffic monitoring system.

Sensors embedded in road materials -- called "smart structures"-- for use in major highways will allow staff at computer control centers to monitor the pace of traffic and identify slowdowns or other problems. The ORNL researchers must determine the compatibility of the sensors with road materials, such as asphalt and concrete, before they can develop smart structures. They will test the effects of extreme temperatures and other conditions on the sensors to determine their durability.

Another project is to develop and implant silicone rubber fibers into reusable shipping containers made of polymer-based composite materials. The fibers will serve as sensors for quickly and easily monitoring the containers' structural integrity.

Supercond Technology, a minority-owned company, specializes in defense technology conversion focusing on smart-materials development and advanced communication systems for aerospace and other commercial applications.

Thomas Mensah, president of Supercond, said the research is expected to have applications far beyond the 1996 traffic flow in Atlanta.


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