Optimization of Lithium-Ion Battery Pouch Cell for Maximization of Energy Density while Preventing Internal Short Circuit Caused by Separator Failure under Crush Load

Lithium-ion batteries (LIBs) for electric vehicles are exposed to large deformations and damage caused by vehicle accidents. Therefore, there exists an internal short circuit (ISC) risk owing to separator failure. This paper proposes a framework for optimizing the energy density while preventing the separator failure of a LIB pouch cell. In this study, the separator failure of the pouch cell was evaluated according to the SAE J2464 crush test standard using a representative sandwich (RS) mechanical model. The energy density and power density performance were evaluated by constant current discharge using an electrochemical model. The constraints of the optimization process were the separator strain evaluated by the crush test and the power density of the initial design. The optimal solution was obtained using a metamodel and global optimization algorithm. The optimization improved the energy density by 9.57% and ensured the safety of the LIB pouch cell separator under a crush load.

Automated summary

This study introduces a framework for optimizing the energy density of lithium-ion batteries (LIBs) for electric vehicles while preventing separator failure, evaluating separator failure and performance using representative sandwich mechanical model and electrochemical model. The optimal solution was obtained using a metamodel and global optimization algorithm, improving energy density by 9.57% and ensuring the safety of the LIB pouch cell under crush load.