It remains difficult to detect internal mechanical deformation and gas-induced degradation in lithium-ion batteries, especially outside specialized diagnostics laboratories. In this work, we demonstrate that electrochemical acoustic time-of-flight (EA-ToF) spectroscopy can be used as an insightful and field-deployable diagnostic/prognostic technique to sense the onset of failure. A 210 mAh commercial lithium-ion cell undergoing thermal abuse testing is probed with in situ and operando EA-ToF spectroscopy, together with simultaneous fractional thermal runaway calorimetry (FTRC) and synchrotron X-ray imaging. The combination of X-ray imaging and EA-ToF analysis provides new understanding into the through-plane mechanical deformation in lithium-ion batteries through direct visualisation and the acoustic ToF response. Internal structural changes, such as gas-induced delamination, are identified using EA-ToF spectroscopy due to variations in the attenuation and signal peak shifts. This is corroborated using X-ray imaging, demonstrating EA-ToF spectroscopy as a promising technique for detecting onset of battery failure.

仍然很难检测到锂离子电池的内部机械变形和气体引起的降解，尤其是在专门的诊断实验室之外。在这项工作中，我们证明了电化学声学飞行时间（EA-ToF）光谱技术可以用作有洞察力和现场部署的诊断/预后技术，以检测故障的发生。进行热滥用测试的210 mAh商业锂离子电池采用原位和操作方式进行探测EA-ToF光谱，以及同时的分数热失控量热法（FTRC）和同步​​加速器X射线成像。X射线成像和EA-ToF分析相结合，通过直接可视化和声学ToF响应，提供了对锂离子电池通过平面机械变形的新理解。由于衰减和信号峰位移的变化，使用EA-ToF光谱可识别内部结构变化，例如气体引起的分层。X射线成像证实了这一点，证明EA-ToF光谱技术是检测电池故障开始的有前途的技术。