Engineers tackled the familiar issue of battery deterioration in a practical technology that many people rely on every day: wireless earbuds.
Have you ever wondered why the batteries in your electronics don’t seem to last as long as they did when they were new?
A global research group spearheaded by The University of Texas at Austin has addressed this common problem of battery degradation with a different approach. Their focus is on wireless earbuds, a technology we frequently use. They utilized x-ray, infrared, and other imaging techniques to delve into the intricate technology within these small devices and understand the reasons behind their declining battery performance over time.
“It all began with my personal headphones; I only use the right one, and I noticed that after two years, the left earbud still had a significantly longer battery life,” shared Yijin Liu, an associate professor in the Cockrell School of Engineering’s Walker Department of Mechanical Engineering, who led the study recently published in Advanced Materials. “This prompted us to investigate further and see what we could uncover.”
The researchers discovered that vital components of the compact earbuds, such as the Bluetooth antenna, microphones, and circuits, interacted unfavorably with the battery, leading to a problematic microenvironment. This situation resulted in a temperature difference—varied temperatures at the top and bottom of the battery—that caused damage.
Real-world exposure also contributes to the issue, with fluctuating temperatures, varying air quality, and other unpredictable factors affecting performance. While batteries are engineered to handle tough conditions, the frequent changes in the environment present their own set of challenges.
The researchers argue that these results highlight the necessity of considering how batteries integrate into everyday devices like smartphones, laptops, and cars. What packaging solutions can reduce harmful interactions with sensitive components, and how can battery performance be tailored for different user habits?
“The way people use devices alters the battery’s behavior and efficiency,” noted Guannan Qian, the lead author of the study and a postdoctoral researcher in Liu’s lab. “Exposure to various temperatures, individual charging practices, and unique driving styles for electric vehicle users all influence battery performance.”
For their experiments, Liu and his colleagues partnered closely with UT’s Fire Research Group, led by mechanical engineer Ofodike Ezekoye. They combined Ezekoye’s infrared imaging technology with their x-ray equipment at UT Austin and Sigray Inc. To gather comprehensive data, they also accessed some of the most advanced x-ray facilities in the world.
They collaborated with teams from renowned institutions like SLAC National Accelerator Laboratory’s Stanford Synchrotron Radiation Lightsource, Brookhaven National Laboratory’s National Synchrotron Light Source II, Argonne National Laboratory’s Advanced Photon Source, and the European Synchrotron Radiation Facility (ESRF) in France. These prestigious laboratories provide researchers with access to top-tier synchrotron facilities, allowing them to uncover the intricate dynamics of batteries under realistic conditions.
“Typically, in lab settings, we either examine stable and pristine situations or extreme cases,” explained Xiaojing Huang, a physicist at Brookhaven National Laboratory. “As we innovate and develop new battery types, it’s crucial to recognize the discrepancies between lab environments and the unpredictable nature of the real world. X-ray imaging can provide essential insights into these differences.”
Liu mentions that his team will continue to explore battery performance in real-world scenarios, potentially expanding their research to larger batteries used in devices like smartphones, laptops, and electric cars.
The full research team includes: Tianxiao Sun and Ayrton M. Yanyachi from the Walker Department of Mechanical Engineering; Guibin Zan, Jizhou Li, Dechao Meng, Vivek Thampy, Sang-Jun Lee, Jun-Sik Lee, and Piero Pianetta from SLAC; Sheraz Gul and Wenbing Yun from Sigray; Xiaojing Huang, Hanfei Yan, and Yong S. Chu from Brookhaven National Laboratory; Juanjuan Huang and Shelly D. Kelly from Argonne National Laboratory; Peter Cloetens from ESRF; and Kejie Zhao from Purdue University.
