Solid electrolytes are key to making batteries more powerful and safer
For more than 30 years, Steve Martin has been studying and characterizing different materials to identify properties that would allow for optimal energy transfer and storage in batteries. He says ceramic-like sulfide glasses may hold the solution, and now he’s working on a project to scale up his fundamental research and ultimately assemble and test batteries with this technology.
Martin, an Anson Marston Distinguished Professor in Engineering in Iowa State University’s Department of Materials Science and Engineering and an associate of the U.S. Department of Energy’s Ames Laboratory, says his life’s work is inspired by the need to reduce the world’s reliance on fossil fuels.
“We’ve realized the negative consequences of burning oil, and we need to find ways to improve batteries to better support alternative energy sources and applications, like wind energy and electric automobiles,” he adds.
Martin’s latest project aims to create a new type of electrolyte based on solids instead of the liquid electrolyte we see in today’s lithium-ion batteries.
“The electrolyte’s job is to separate a battery’s electron-producing anode from its electron-accepting cathode. Because liquid electrolytes are highly flammable, batteries have been purposely designed with 10 times less energy density than is actually possible to avoid catching fire,” he explains.
The solid electrolyte Martin is developing is stronger and non-flammable compared to liquid electrolytes. These two factors alone will allow the researchers to create a battery that can store more energy at a higher voltage and that is safer for a wider range of temperatures, both hot and cold.
Finding the right chemistry for these electrolytes has taken Martin and several other researchers years to discover, but it’s been worth the wait. The new batteries will essentially be thin film, manufactured in such a way that they will be denser and more durable, and they will help improve a range of alternative energy technologies.
Martin’s work is most recently supported by a three-year, $2.5 million grant from the U.S. Department of Energy’s Advanced Research Projects Agency – Energy and its new Integration and Optimization of Novel Ion-Conducting Solids (IONICS) program. There’s additional, cost-share funding from Iowa State and the Iowa Energy Center.
The funding also supports the work of Jing Xu, a newly hired assistant professor of materials science and engineering, three postdoctoral researchers, two doctoral students and three undergraduates.
“With Dr. Xu’s expertise in assembling and testing batteries and my understanding of making electrolytes, we’re going to see some significant advancements through this project,” Martin says. “It’s great to see momentum picking up around battery research, because I know progress in this area will bring tremendous value to society.”