A simultaneously coupled modeling approach to study the electrochemical and thermal behavior of lithium-ion batteries under large mechanical deformation has been developed. The thermo-electrochemical pseudo-2D (P2D) battery model is coupled with a mechanical material model.
Deformation and failure characteristics of four types of lithium-ion battery separators Li-ion battery separators, mechanical integrity and failure mechanisms leading to soft and hard internal shorts Coupled mechanical-electrical-thermal modeling for short-circuit prediction in a lithium-ion cell under mechanical abuse
With increasing deformation, loads on the batteries with different SOCs show a virtually identical upward trend in the early stage. When deformation exceeded 2 mm, batteries with 40% SOC and above soon reached the peak load and failed, indicated by a sudden loss (dive) in voltage.
Deformation and failure of Li-ion batteries can be accurately described by a detailed FE model. The DPC plasticity model well characterizes the granular coatings of the anode and the cathode. Fracture of Li-ion batteries is preceded by strain localization, as indicated by simulation.
Fracture initiates from aluminum foil and ends up with separator as the cause of short circuit. Safety of lithium-ion batteries under mechanical loadings is currently one of the most challenging and urgent issues facing in the Electric Vehicle (EV) industry.
In addition, under quasi-static axial compression, the intensity of thermal runaway becomes more severe with the increase in SOC and loading speed. The results shed light on the failure mechanism of lithium-ion batteries under axial load and guide the safety design of the battery and safety arrangement of battery packs.