Ultrasonic measurements offer insights into cell behavior and aging during cycling. For the Graphite/NMC cell tested, the ToF consistently increased during charging and decreased during discharging likely due to changes in density and Young’s modulus of the graphite anode. A two-week cycling pause at cycle 100 led to a temporary drop in ToF, followed by a return to previous levels after further cycling. This effect is consistent with the recovery in state of health (SoH) after a break, indicating an inverse relationship between ToF and SoH. Higher values of ToF can be correlated with a lower SoH. In contrast, the correlation between the maximum amplitude during charge/discharge and SoH, as an indicator of degradation, is weaker. These initial findings highlight the potential of ultrasound-based diagnostics for in-situ battery monitoring. Spectroscopic methods employing various excitation frequencies promise further insights into aging processes, including the separation of effects in specific battery cell components.