Fracture mechanics modelling of lithium-ion batteries under pinch torsion test

For the design of batteries to sustain the crash tests, the mechanical strength (force generated) on the battery can be evaluated to understand its fundamental effect on possible failure (such as breaking of separator and short-circuit) of batteries. In this perspective, this study proposed a holistic approach to evaluate the maximum force generated on the battery when subjected to the pinch-torsion test. The fundamentals of the test are understood by formation of Finite element analysis (FEA) model and validated based on experiments. The inputs in FEA such as the temperature, the displacement and the strain rate are varied and the maximum generated force is observed on the battery. The quantification of the finite element data is further performed by an optimization approach of GP. It was found that the GP model for an evaluation of mechanical force on the battery is accurate. The robustness in the model is validated by design of its simulation for 10,000 runs. 2-D and 3-D surface analysis suggests that the displacement due to indentation is the most dominant followed by the temperature and the strain rate. The findings from the analysis can pave the way for design of new battery that comprises of higher strength when subjected to the crash tests.