Condition monitoring of State of Charge (SOC) and State of Health (SOH) is critical for ensuring the safety, reliability, and performance of lithium-ion batteries (LiBs) across a wide range of applications. Acoustic sensing has emerged as a promising technique for characterizing internal battery states in a non-invasive manner. This study introduces a novel acoustic methodology for real-time monitoring of SOC in pouch-type LiBs during charge–discharge cycles, as well as SOH following calendar aging, using spectral centroid (SC) analysis of frequency-swept active acoustic signals. Key contribution includes the development of a hybrid modeling framework integrating finite element (FE) simulations with experimental validation. SOH was evaluated by repeating on the same batteries after 5-month storage under controlled laboratory conditions. The results provide clear evidence of mechano-electrochemical coupling effects resulting from lithium-ion intercalation/deintercalation, solid electrolyte interphase (SEI) growth, and loss of active material (LAM) during both cycling and aging processes. The correlations observed between acoustic features and SOH offer a possible cost-effective and scalable enhancement to existing non-destructive evaluation (NDE) techniques. This research establishes an acoustic-guided wave-based diagnostic framework capable of tracking dynamic changes in material properties, thereby facilitating early failure mode detection and supporting the development of predictive maintenance strategies. • A novel framework with spectral centroid analysis with swept active AE signals. • FE and validation tests identifying material changes linked to LLI and LAM. • A hybrid method bridging insights with aging mechanism and SOC and SOH evaluation. • Resonance peak shifts reveal mechano-electrochemical effects for material tracking.
Fu et al. (Tue,) studied this question.