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TTU News

Dead batteries for the gadgets and toys under the tree can short-circuit Christmas joy, but a Tennessee Tech University professor at TTU's Center for Manufacturing Research is working on the latest in battery and fuel cell technology that may change the way we power everything from smart credit cards to automobiles.

Chunsheng Wang, along with TTU graduate and undergraduate students, is working on improved power sources that promise to be more efficient, versatile, powerful and cleaner than what we now enjoy.

"Working to improve the performance of the common battery, we've tested a new structure of a thin-film, lithium-basted battery, and the results have been good," says Wang, who arranged a collaboration with Oak Ridge National Laboratory on a novel all-solid-state micro/nano battery and supercapacitor architecture. "It has the potential to power even nano devices and machines.”

Developed by an ORNL group led by researcher Nancy Dudney, the thin film Li-ion battery has a conventional three-layer structure (anode-electrolyte-cathode) and exhibits excellent performance characteristics to meet the requirement for microdevices.

However, if the interfaces between electrodes and electrolytes, which produce a high overpotential, can be removed to form an interface-free microbattery, the volume of the ORNL thin film battery can be significantly reduced without sacrificing its performance. A provisional patent related to this novel architecture was filed by TTU on April 14.

The thin film battery, which has potential for commercial and national defense applications, is rechargeable and small. How small? It’s designed to be thinner than common plastic wrap, or even possible in nanoscale.

Unlike traditional batteries, the thin-film micro-battery is intended for small, high-technology applications such as smart credit cards, security cards, wireless sensors, radio frequency identification tags, chip memory back-up and advanced drug delivery devices.

But Wang isn't just thinking small in his research. His work is also bringing the zinc-air fuel cell — essentially a big battery — closer to reality. Zinc-air fuel cells produce electrochemical energy by using oxygen straight from the air. It is a high-energy, high-power technology that is safe and environmentally benign.

Industry leaders predict that with these fuel cells, automobiles would be able to run about 300 to 400 miles before recharging. They require no special conditions, such as high pressure or extreme cold, for storage of the fuel. The fuel cells may even be able to use portable rechargers that can run on household electricity.

Current zinc-air batteries are popular for handheld electronics, including hearing aids and pagers, because they provide three times the energy of common alkaline batteries.

Thanks to Wang's instruction and support, TTU's Chem-E Car team recently won a national competition by competing with a vehicle powered by a zinc-air fuel cell. Under the professor's direction, students designed and tested the cell, which was more robust than previous types used in competition.

"It worked out great for the competition because a zinc-air battery is high in energy and cheap to build, but the durability is not good," says Wang. "This is what the students will be working to improve on and what we as researchers are working to do so that using these fuel cells in automobiles can be a practical reality."
Seeing students succeed in the classroom and in competition is what Wang anticipated when he joined the university.

"I came to Tennessee Tech to work with undergraduate students to help them learn what is possible," he says. "I have been able to teach my students what is possible with my research efforts."