Multiaxial failure characterization and short-circuit prediction of large-format prismatic lithium-ion batteries

Prismatic lithium-ion batteries (PLIBs) are becoming the most prevalent battery type in electric vehicles. With their widespread application their safety performance under mechanical abuse has become a hot topic. This study systematically investigates the mechanical-electrical coupling failure mechanisms of PLIBs in different loading directions through an integrated experimental and computational approach. Separator-anode-separator-cathode stacking experiments were designed to reveal the internal short circuit (ISC) mechanism triggered by damage and failure of battery components under three loading directions. Two ISC modes, minor ISC and major ISC, were identified based on the observed slow and sharp voltage drops in the components stacked experiments. Furthermore, a novel simplified modeling framework for large-format PLIB was proposed to efficiently capture both the global mechanical response and local deformation/failure characteristics of the battery. Finally, based on the experimental insight and finite element modeling, ISC criteria were proposed based on separator functional failure for minor ISC and collector fracture failure for major ISC. The proposed short-circuit criterion provides a rapid prediction method for PLIBs used in electrical vehicles, and the research results provide a significant advance for the safe design, application, and analysis of next-generation large-format PLIBs.