Equivalent Mechanical Model for Cylindrical Lithium-ion Battery Under Mechanical Abuse and Soft Short-circuit Failure Warning

Abstract

Based on the analysis of the experimental data for cylindrical lithium-ion battery under mechanical abuse, an equivalent mechanical model of spring-damping parallel unit connects a damping unit in series is proposed in this paper. By combining the equivalent mechanical model with the Crushable-Foam material model, the experiments and simulations on the flat plate tests, rigid rod tests and hemispherical punch tests are performed, the prediction error of the simulation model to the failure displacement is less than 11%. After that, the equivalent mechanical model is analyzed, a soft short-circuit failure prediction model is proposed. A failure warning system is designed according to the prediction model, and the warning system can prompt the soft short-circuit failure of the battery in time and has a certain safety margin.