Comparative study of vibrational behaviour of lithium-ion batteries under different axis orientations

Abstract

The impact of placement orientation on vibration-induced electrochemical degradation of three different lithium-ion battery geometries, namely, pouch, prismatic, and cylindrical, are investigated in this research. The batteries are subjected to 24-hour continuous vibration in each test based on a modified IEC62660–2 vibration standard. Electrochemical impedance spectroscopy (EIS), capacity fade analysis, and average discharge voltage (DV_avg) analysis are performed to evaluate the impact of vibration on the electrochemical performance of batteries. The experiments are conducted in both single-axis orientation and 3-in-1 multi-axis combined orientation using custom-designed fixtures. The results show that the rate of vibration-induced degradation in batteries varies significantly with their placement orientation. Similar trends are observed from both single and multi-axis test settings. Cylindrical batteries show a more significant capacity reduction with a maximum of 9.52 % when vibrating along their radial axes than their longitudinal axis. On the other hand, prismatic and pouch batteries show more substantial degradation that is just below 1 % when subjected to vibration along their length (long axis) compared to their width or thickness. These findings emphasize the need to consider battery placement orientation while selecting and packaging lithium-ion batteries for electric vehicles (EVs), specifically for structural battery applications.