In what may signify a leap forward for battery safety and longevity, MIT researchers have developed a method to interpret the faint, yet telling, sounds produced by lithium-ion batteries. These sounds, once indecipherable amidst the noise, now offer insights into the battery’s health and potential for failure. According to a recent article on MIT News, the team’s analysis correlates specific acoustic patterns with internal degradation processes, potentially revolutionizing how we monitor and predict battery performance.
Under the guidance of Martin Z. Bazant, Chevron Professor of Chemical Engineering and professor of mathematics at MIT, graduate students Yash Samantaray and Alexander Cohen, along with former MIT research scientist Daniel Cogswell PhD ’10, worked together to decode these emissions. They identified them as byproducts of gas bubbles from side reactions or fractures caused by the expansion and contraction of materials. “In this study, through some careful scientific work, our team has managed to decode the acoustic emissions,” Bazant told MIT News. The findings were published in the journal Joule on September 5.
The research involved coupling electrochemical testing with the recording of acoustic emissions under normal battery operation. This enabled the team to develop a cost-effective method of understanding critical phenomena, such as gas generation and material fracture. These are significant since they often precede battery degradation and failure. “We were able to come up with a very cost-effective and efficient method of actually understanding gas generation and fracture of materials,” Samantaray explained on MIT News.
Further refining their process, the researchers integrated a technique known as wavelet transform to isolate vital data from the surrounding clamor, a novel approach according to Bazant. “No one had done that before,” he said, therefore, it marked another breakthrough. Acoustic emissions, while commonly used in other sectors to forecast potential failures, have lacked a systematic interpretation framework in the context of batteries, until now.
These groundbreaking methods might soon manifest in practical applications. One such development is underway in collaboration with Tata Motors, aiming to integrate a battery monitoring system in their electric vehicles. The MIT team’s research has also highlighted the potential for using acoustic emissions to pre-empt thermal runaway situations, which can lead to hazardous fires. As Bazant explained, this kind of monitoring is akin to catching the first small bubbles before water reaches a boiling point, offering crucial early warnings.
The potential uses of these insights go beyond just monitoring existing batteries; they could also improve the development and manufacturing processes. “As a lab tool for groups that are trying to develop new materials or test new environments, so they can actually determine gas generation or active material fracturing without having to open up the battery,” Samantaray suggested on MIT News. Additionally, Bazant sees opportunity for the system to act as a quality control measure during the battery formation cycling in production, thereby enhancing the selection of well-formed cells from the outset.
The implications of such technology are vast, with benefits likely to extend across the sectors reliant on battery systems, including electric vehicles and grid-scale storage facilities. Not only could this advance warn against immediate dangers, it promises enhanced forecasting of battery lifetimes, ushering in a new era of reliability for the battery-dependent world. The project has garnered support from several prominent institutions, including the Toyota Research Institute, the Center for Battery Sustainability, the National Science Foundation, and the Department of Defense, and utilized facilities at MIT.nano.