Multimodal Assessment of Battery Aging by Coupling Ultrasound and Impedance Signatures

Battery aging is a complex process driven primarily by material degradation and accelerates under harsh cycling conditions, ultimately limiting performance. Herein, we investigate electro-mechanical degradation under representative charge/discharge protocols (3.0C/0.2C, 1C/2C, and 0.5C/0.5C) and show that combining ultrasound sensing with electrochemical impedance spectroscopy (EIS) enables accurate assessment of electro-mechanical degradation. Ultrasound detects mechanical defects by tracking shifts in the power spectral density of acoustic signals, while EIS captures the early onset─or absence─of degradation. Combined, these techniques provide a framework for battery health monitoring, with each addressing limitations of the other.