Mechanical Degradation on Defective Lithium-Ion Batteries

Abstract

Unavoidable minor electric vehicle collisions can cause defects and deformations in lithium-ion batteries (LIBs). The safety of such defective batteries is crucial for ensuring the overall safety and stability of battery systems. However, the usability of a defective battery and the mechanisms underlying the damage remain unclear. In this study, we focus on the mechanical performance of defective batteries, safety thresholds, and the associated failure mechanisms. Initially, two typical defective cells are prepared by quasi-static loading using different indenters. The mechanical responses of these cells are then assessed via quasi-static flat compression. Finally, a mechanical failure criterion for the battery is proposed based on the thickness of the separator. The effects of defect area and defect angle on the performance of defective cells are also discussed. These results provide valuable insights for the safety assessment and management of defective lithium-ion batteries.