Batteries in technology like wireless earbuds degrade unevenly due to conflicting conditions within the device, a UT-led research team found in an international study released Jan. 31.
“The bottom line is that we do realize the laboratory research on batteries has a gap from the real world applications,” said Yijin Liu, the research lead and an associate professor in the Cockrell School of Engineering’s Walker Department of Mechanical Engineering.
Liu said when new battery materials are developed, they are typically tested in stable temperatures and controlled cycling conditions. However, he said these tests do not account for real-world factors, such as consumers’ varied charging patterns and fluctuating temperatures within the environment that can significantly impact battery performance and lifespan in everyday devices.
Using advanced imaging techniques like X-ray technology and infrared imaging, the team analyzed the battery without dismantling the earbud. Their findings revealed conflicting temperatures inside the device created an unstable microenvironment within the earbud, leading to battery degradation.
“Our results show that the bottom part of the (earbud’s battery) was damaged most severely, the top part had a little damage and the middle part has no damage whatsoever,” Liu said. “That was a little bit strange.”
Liu said the earbuds packaging plays a key role in possible battery damage, leading to different parts of the battery degrading unevenly.
“For this particular case, (the study) could inform the design of the earbuds, but more broadly, it can tell us the importance of the microenvironment: the packaging,” Liu said. “If you look at cell phones, laptops or electric vehicles, it becomes larger and more complicated, so this microenvironment is universally important.”
Liu said he hopes manufacturers will use their research to better lab testing for batteries, making it more reflective of real-world conditions to enhance the performance of future products.
“This in-depth study is useful as feedback to the industry and also to guide the design of the next generation of devices,” Liu said.
