Ultrasonic guided waves as an indicator for the state-of-charge of Li-ion batteries

Published: 11 October 2023| Version 1 | DOI: 10.17632/ts9ryskpxs.1
Benjamin Reichmann, Zahra Sharif-Khodaei


Data This dataset forms part of the data used for the following article https://doi.org/10.1016/j.jpowsour.2023.233189. It includes the ultrasonic guided wave data collected during one 0.34C discharge-charge cycle recorded on 13th July 2022. The sensor set-up and required post processing is detailed in the related paper. The data is maintained in its original record format (oscilloscope readings). The following data is included: • Chirp input signal (1 mat file) • Responses of cell to input chirp signal throughout discharge-charge cycle (104 mat files) • Text file containing the voltage, current, temperature, and other parameters. Signal type Generally, a single tone burst signal may be used to excite a cell (e.g., fig 2 e, blue). Correspondingly, the response to this specific tone burst signal with one specific central frequency (fig 2 g, blue) could be measured. However, when collecting these ultrasonic measurements, it wasn’t decided yet which parameters (center frequency, number of excitation cycles) would be ideal for the probed cell. It was therefore decided to excite the cell with chirp signals. A chirp signal contains a wide range of frequencies (fig 2 b). Therefore, the response signal is chaotic (fig 2 c). It’s therefore hard to analyze the response to a chirp signal directly. Using the chirp signal and the response to the chirp signal the transfer function of the cell at each measurement point was calculated and used to compute the expected response to a tone burst signal (formula 4 / fig 2 e and g, red). This allows to quickly try different center frequencies in the post processing and analyze which frequency is best suited for a specific cell (see figure 3). Lab protocol The mat files of the ultrasonic measurements include measurements from all paths between the four sensors (see figure 1). For the analysis in figure 6 the data from sensor 1 (emitter) to sensor 2 (receiver) has been used. A pdf explaining the structure of the mat files is attached. The ultrasonic probing was done in time intervals of 5 minutes not SoC intervals. The SoC can be calculated based on the charge drawn from the cell which is included in the electrical measurements. The ultrasonic chirp signal data and the extrinsic cell parameters may be correlated using the time stamp of each recording. The following steps are included in the data. 13.07.2022: Charge/Discharged cell “Palma” (0.34C) 1. Charge at 6.25A to 4.2 V 2. Charge at 4.2V until I<0.625A 3. Rest 30 min 4. Discharged at 4.25A to 3V 5. Discharged at 3V until I<0.625A 6. Rest 30 min 7. Charge at 4.25A to 4.2 V 8. Charged at 4.2V until I<0.625A 9. Rest 30 min 10. Discharged 2500mAh at 12.5A Between steps 1-9 the following SHM measurement were taken automated every 5 min A. Chirp_24V_100MHz_100us_1-600kHz (Palma20220713Chirp_i)



Ultrasonics, Ultrasound, Lithium Battery, Guided Wave Testing, State-of-Charge