A safer lithium-ion battery for electric vehicles, developed by a University of Rochester chemical engineer and Oak Ridge National Laboratory, has received one of this year’s R&D100 awards, also known as the “Oscars of Invention.”
The awards, sponsored by R&D Magazine, have been given since 1963 to honor innovative breakthroughs in materials science, biomedicine, and consumer products by academia, industry, and government-sponsored research agencies.
The Safe Impact Resistant Electrolyte (SAFIRE), developed by a team at Oak Ridge led by Gabriel Veith and by the laboratory of Wyatt Tenhaeff, assistant professor of chemical engineering at Rochester, improves the safety of plug-in electric vehicle batteries.
In typical automotive lithium-ion batteries, the liquid electrolyte, which conducts the electrical current, poses a fire risk in high-speed collisions and requires heavy protective shielding, decreasing the vehicle’s range and efficiency. SAFIRE eliminates this risk by using an additive that transforms the liquid electrolyte to a solid upon impact, blocking contact between electrodes.
It performs as well as conventional electrolytes under normal conditions and can significantly reduce electric vehicle weight and increase travel distance—helping to overcome some of the biggest hurdles in the way of wider use of electric vehicles.
“The R&D100 is a great acknowledgement of the technology and the concept,” says Tenhaeff, whose lab performed measurements to verify that the stiffening material has the right conductivity for battery cells.
The project has received the first of multiple expected patents, he adds.
Tenhaeff credits the work of one of his PhD students, Brian Shen, who had two opportunities to work at Oak Ridge helping to develop the material.
“It was cool to get the patents and the R&D100, but it was also great to have Brian trained on this, and gain some experience at the national labs,” Tenhaeff says.
Shen spent a total of 11 months at Oak Ridge synthesizing and coating the colloids (stiffening material) and adding them to electrolytes to prepare shear thickening electrolytes. He also tested the shear thickening electrolytes to ensure they would respond in a crash and function properly with the rest of the battery.
“Oak Ridge was great,” Shen says. Working with career research scientists forced him to “step up my game,” he adds. “When I came in, understandably, I didn’t have as much of the knowledge that they did, but interacting with them enabled me to learn more. I also learned how to learn more. I think that’s an important step.” The experience also opened his eyes to other types of battery research he might pursue in industry after he graduates, he says.
The project was supported with seed money from Oak Ridge and from the Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E).
Tenhaeff, who worked as a staff scientist at Oak Ridge prior to joining the Rochester faculty, is also collaborating on two other battery projects funded by ARPA-E.
One seeks to develop solid-state lithium metal vehicle batteries that feature a solid ceramic electrolyte in place of the combustible liquid electrolytes now used.
The project is led by Jeff Sakamoto, an associate professor at the University of Michigan, with whom Tenhaeff collaborated while at Oak Ridge.
Tenhaeff’s mentor at Oak Ridge, Nancy Dudney, a leading expert in solid-state lithium battery design, is also collaborating on the project, along with researchers at the Ford Motor Company and the Army Research Laboratory.
Tenhaeff is also working with Oak Ridge researchers on a project to find glassy lithium-ion conductors that are stable and can be fully integrated into battery cells at a low cost.
Source: University of Rochester