Researchers at the Whiting School and JHU’s Applied Physics Laboratory (APL) are developing lithium-ion batteries capable of operating in some of the world’s coldest environments.
Traditional lithium-ion batteries fail in frigid temperatures because the liquid electrolyte that facilitates the electric charge freezes, rendering the battery inoperable. To address this, a team led by Jesse Ko, a senior staff scientist at APL, and Yayuan Liu, Russell Croft Faculty Scholar and assistant professor in the Whiting School’s Department of Chemical and Biomolecular Engineering, is exploring solvent combinations that would create disorder—called “entropy”—in the electrolyte, lowering its freezing point and ensuring the battery’s performance.
“As long as we increase entropy in a controlled manner, we can lower the electrolyte’s freezing point,” Ko says. “We’ll be investigating various solvent combinations, but it’s tricky because there are almost infinite possibilities.”
Finding the right solvent combination through trial and error is extremely time-consuming. To accelerate the process, the team will use high throughput experimentation, artificial intelligence robot-controlled electrochemistry, and machine learning (ML) to identify entropy-generating factors.
“We’ll collect a lot of data with high-throughput experimentation, then feed it to an ML algorithm to help us find ideal conditions for creating entropy in the electrolyte,” says Liu, an associate researcher in the Ralph O’Connor Sustainable Energy Institute.
The researchers also hope to achieve lab automation. “The idea is to conduct experiments with the robot, feed the results to the ML model, and have the model provide feedback on what combinations work better, creating a loop that accelerates materials discovery,” says Liu.
Their work is timely and has far-reaching implications. “Climate change creates new challenges in the Arctic, where temperatures can reach -40° to -75°F,” says Ko. “If you send a soldier or drone out there, you want the equipment to function as it should.”