Eonix Sponsors ISD Project with New, Non-Flammable E-Bike Battery

Your muscles might feel a bit sore after a long bicycle ride. But lately, some cyclists have been feeling the burn from a different source: the batteries powering their e-bikes. In 2023, 216 e-bike battery fires in New York City led to 147 injuries and six deaths.

"Having relocated from New York to Tennessee, we were acutely aware of the rising threat posed by e-bike battery fires," said Spencer Flottman, the senior battery scientist at Eonix, a company devoted to making inexpensive, nonflammable lithium-ion (Li-ion) batteries.

Charging a Li-ion battery always creates a small amount of heat, but old, damaged, or poorly made batteries can build up heat faster than they can vent it. If the internal temperature gets high enough, the lithium can react with solvents in the battery, sometimes igniting a fire.

"Battery safety is becoming increasingly important as more and more batteries are being used in our daily life," said JiangBiao He, an associate professor in the Min H. Kao Department of Electrical Engineering and Computer Science (EECS) who specializes in electric power conversion systems for transportation electrification.

Eonix moved to Tennessee and began leasing a laboratory in the University of Tennessee's Zeanah Engineering Complex in 2018. With the state-of-the-art lab, cutting-edge tech, and funding from the United States Department of Defense (DOD), Eonix has already successfully developed a non-flammable Li-ion battery cell.

Of course, moving to UT also gave them access to another vital resource.

"We've been incredibly impressed by the caliber of UT's engineering students," Flottman said.

Eonix has already hired several UT graduates. Last fall, the company expanded its partnership with the university by sponsoring an Interdisciplinary Senior Design (ISD) project for students in the Tickle College of Engineering (TCE) and the Haslam College of Business.

"This project is important because it is introducing a new, safe battery pack design," said Elijah Raffel, one of the four EECS majors on the team. "It also represents a leap in making green energy more available and widespread."

Hands-on Interdisciplinary Experience

As the finale of the Integrated Engineering Design program, an ISD brings students from multiple disciplines together to design, test, and prototype products that respond to the real needs of industry sponsors.

In this case, Eonix needed a battery management system that could facilitate testing and safety evaluations while being inexpensive enough for everyday consumers to access.

"Despite our expertise in materials design, we lacked the engineering experience required to integrate our technology into a consumer product like an e-bike battery," Flottman explained.

The Eonix ISD team includes four EECS majors—Raffel, Ethan Naugle, Seamus Meagher, and Garrett Bailey—as well as mechanical engineering major Ally Collier and finance major Isabella Siegrist.

"Multi-disciplinary projects are much closer to the projects that students will work in after graduation," said He, the team's technical mentor. "We truly appreciate the financial sponsorship and technical support Eonix has been giving these students, who are gaining valuable hands-on experience beyond conventional classes and textbooks."

Eonix tasked the student team with designing a battery management system that would allow its non-flammable Li-ion battery to be wirelessly monitored during testing—and discovering the best way to configure the battery cells and management system into a full battery module.

"There is so much to consider when dealing with battery management, and this project has allowed us to dig deeper into both battery technology and analog design," said Meagher. "It has been an inviting challenge."

The project also included an economic impact analysis of e-bike battery fires, cost and pricing strategies for the students' module, production and partnership models Eonix could use to scale up its design, and a marketing strategy for the final product.

"Finding a definite direction to go in for each step was challenging," Bailey said. "The folks at Eonix had a general idea of where this project was headed, but they gave our team a lot of freedom in the execution."

For example, the students were unsure whether Eonix should partner with battery manufacturers or make its own battery modules. Rather than asking for a decision from Eonix, the ISD students opted to interview industry leaders and safety advocacy groups, then follow their recommendations.

As they count down the days to the ISD Showcase, the Eonix team's students are tweaking the file they use to 3D print the battery module casing, refining their voltage monitoring software, and polishing their Bluetooth-enabled monitoring app.

"By the conclusion of this project, UT students will have successfully demonstrated our ultra-safe lithium-ion battery technology within an e-bike," Flottman said. "This milestone will not only open new market opportunities for Eonix but, more importantly, enable us to provide a safer battery solution for New Yorkers and beyond."

Provided by University of Tennessee at Knoxville