Impacts of vibration and cycling on electrochemical characteristics of batteries

Lithium-ion batteries inevitably encounter vibration in practical applications, necessitating in-depth research on the impact of vibration on the electrochemical performance of batteries. This study investigates the alterations in the electrochemical performance of batteries subjected to vibration at different frequencies and the changes in cyclic batteries after vibration. The degradation mechanism of the battery during vibration and cycling is revealed through electrochemical characterization and post-mortem analysis. The results indicate a significant decrease in stored electric energy within the battery after vibration. The direct current internal resistance of the battery shows a minor increase, while the impedance of the solid electrolyte interface (SEI) and the charge transfer impedance slightly decrease after vibration. In addition, black stripes appear on the surface of the separator, and broken particles are observed on the anode surface. Compared to fresh batteries undergoing direct cycling, the cycling performance of the battery significantly deteriorates after vibration. The impedance at each stage exhibits a significant increase, and the IC peak exhibits a significant decrease and deviation. Vibration exacerbates the loss of lithium inventory (LLI) and active materials (LAM) during the cycling process of batteries. This study can provide guidance for enhancing the shock absorption design of batteries in practical applications.