Researchers from the College of Engineering developed a standard testing process to give manufacturers a better look at the internal workings of batteries. Using ultrasound technology, they can now monitor the electrochemical and mechanical functions of a battery to find any damage or flaws that could lead to overheating and other disasters.
“While lithium-ion batteries have been studied for nearly half a century and commercialized for over 30 years, we have only recently developed tools that can see inside with high resolution,” explains Wes Chang, an assistant professor and primary investigator of the The Electrochemical Dynamics Lab, who supervised the project.
Chang’s team has demonstrated that a low-cost, accessible benchtop ultrasonic tool could be easily implemented and used by battery engineers, including those who work at automotive companies producing electric vehicles. Current safety and quality control processes for manufactured batteries rely on visual inspection and performance testing; they could be X-rayed to generate a high-resolution interior image, but this is slow and expensive. By contrast, the Drexel team proposes using ultrasound, which is less expensive and faster, to provide complementary information about the mechanical properties of the battery.
The group plans to continue improving the technology so that it can more easily scan battery electrodes. For instance, the group very recently published a peer-reviewed scientific article in ACS Energy Letters demonstrating the ability of a non-contact ultrasound method for mapping defects in battery electrodes. This shows the technique is useful not only for assembled cells but also for directly diagnosing the electrode layers that are used within the cells, something not done before. From metal impurities to density variations, these detected features on electrodes are the origin points of failure, and a challenge to detect with existing methods such as optical cameras and lasers used in battery manufacturing.
“We hope that by lowering the barrier to entry, ultrasonic testing can become a routine part of battery research and development,” Chang says. DM
