A laptop computer, cell phone or even a NASA Mars Explorer Rover is only as dependable as the battery that powers it, and Chemical Engineering assistant professor Chunsheng Wang is producing award-winning research to improve the fastest growing, most promising battery chemistry — the lithium-ion battery.

Wang, who works with Center for Manufacturing Research, has been named the 2006 Sigma Xi research award winner for his paper, "Solvent-Free Composite PEO-Ceramic Fiber/Mat Electrolytes for Lithium Secondary Cells," published in the first 2005 issue of the Journal of The Electrochemical Society.

"Dr. Wang's innovation improves the performance of solid lithium-ion rechargeable batteries by increasing conductivity, thus reducing thickness, weight and volume, which in turn makes the batteries more efficient," says Ken Currie, director of the CMR. "His work represents a significant breakthrough in the development of an improved composite electrolyte used in lithium-ion cells."

For the average person, lithium-ion batteries are important because they are a type of rechargeable battery commonly used in consumer electronics. They are ideal for portable devices, like notebook computers and cell phones, because of their light weight and high energy density. They also have a slow loss of charge when not in use and have no memory effect, which means their ability to take a complete charge is not incrementally lost. They also do not use poisonous metals, such as lead, mercury or cadmium.

Wang says the widely used commercial batteries typically operate at moderate temperatures and rates. Current lithium batteries in use cannot satisfy some requirements for applications in outer space, such as high-rate rapid charge and discharge and long cycle life. However, his award-winning paper addresses aerospace applications for the lithium battery that require good low-temperature performance and high-power density in a wide temperature range from -30 degrees Celsius to +60 degrees Celsius.

"This work eliminates the use of a liquid electrolyte in the battery, and instead uses a superior sold-state composite electrolyte," Wang says. "This leads to a significant increase in battery charge and discharge cycling stability without increasing battery size and also leads to safer batteries by eliminating the extremely flammable liquid commonly used in lithium-ion batteries."

Featured as one of the more promising battery technologies in a NASA Tech Brief, Wang's work is supported by NASA's John H. Glenn Research Center, one of 10 field centers that develop partnerships with government, industry, and academia. NASA aggressively pursues lithium-ion battery research, even using the batteries in the Mars Explorer Rovers.

Before joining TTU in 2003, Wang worked as a research scientist for the Texas Engineering Experiment Station at Texas A&M University. The subcontracted work has resulted in three companies asking to negotiate for potential licensing agreements for this technology. The technology is currently under a pending patent.

Sigma Xi is an international scientific research society. Each year, the Tennessee Tech chapter recognizes excellent scientific research by one faculty member for a research paper published or accepted for publication in a peer-reviewed, professional journal.

Last year's award winner was Xubin He, assistant professor of electrical and computer engineering.