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Tenhaeff explores new electrolyte design for lighter, safer lithium ion battery packs.

September 25, 2013

tenhaeffWyatt Tenhaeff, the newest member of the Chemical Engineering faculty, will spend the next year exploring whether engineered electrolytes can be designed to create lighter and safer lithium ion battery packs that power electric and hybrid vehicles. Tenhaeff, will be working with Dr.Gabriel Veith, a senior staff scientist at Oak Ridge National Laboratory (ORNL), who is the principal investigator of the project; Tenhaeff worked in the same group with Veith at ORNL before joining the ChemE faculty this summer.

Current lithium ion batteries use flammable non-aqueous electrolytes, and thin polymer separators are required to prevent electrical shorts. In an accident the separator can be punctured, resulting in the battery electrodes contacting each other, shorting the battery, and potentially causing a fire or other safety problems. As an added precaution, the battery packs are often enclosed in a roll cage, encasing them in steel or other heavy, absorbent materials. This adds substantial weight to the car and also limits where the battery can be located.

The ORNL team and Tenhaeff will explore replacing both the electrolyte and separator with a safe impact resist electrolyte (SAFIRE), which can instantaneously transform into an impenetrable barrier in situ upon application of an external force - during a vehicle collision, for example." This would improve the safety of the vehicle battery system without the need for additional protective enclosures, thereby reducing weight, improving the car's mileage, and giving designers more flexibility in where the battery is located.

"This is an ARPA-E seedling grant," Tenhaeff explained. SAFIRE "is an unproven technology. It's a novel idea, and this grant will provide us the resources to rapidly develop it into a more mature technology. With promising results, we hope to generate additional investment interest."  The challenge is "adapting existing lithium ion battery electrolyte chemistry to have this multifunctional behavior," Tenhaeff said.

The project is being funded by a one-year, $450,000 grant, through the Department of Energy's ARPA-E program. ARPA-E, the Advanced Research Projects Agency-Energy, was modeled after the successful Defense Advanced Research Projects Agency (DARPA) in order to advance high-potential, high-impact energy technologies that are too early for private-sector investment, but have the potential to radically improve U.S. economic security, national security, and environmental well-being.