Mechanical vibration modeling and characterization of a plastic-cased lithium-ion battery

Batteries often show the coupling change of multiple physical field characteristic parameters in the charging or discharging processes. Conventional battery modeling and characterization methods mainly focus on electrical or thermal parameters. Considering that battery state change can cause a change in the mechanical structure, research on the vibration characteristic modeling and characterization of a plastic-cased lithium-ion battery is carried out. By analyzing the mechanical structure of the battery, the first principles modeling method is selected to model the battery's mechanical performance. The vibration data in the process of battery charging and discharging are measured by a laser Doppler vibrometer (LDV). The obtained experimental data are used to identify the mechanical parameters of the battery. Based on the experimentael results, the root mean square error (RMSE) of the frequency domain amplitude fitting result of the model is less than 11.36%. The effectiveness of the battery mechanical vibration model is verified. The model and the characterization method provide tools for nondestructive battery state evaluation.