Performance reliability analysis and optimization of lithium-ion battery packs based on multiphysics simulation and response surface methodology

Reliability optimization has always been an important topic in the application of lithium-ion batteries in electric vehicles. To optimize the redundancy and layout design of battery packs accurately and efficiently, a novel reliability optimization method based on a multiphysics coupling simulation and a response surface methodology is proposed. An electrochemical-thermal-fluid dynamics model, a temperature-dependent stochastic degradation model and a multistate performance reliability model are developed. A response surface method with the BoxBehnken design method is applied to reduce the number of simulation trials. Then, the redundancy scheme and two layouts of a battery pack are optimized, followed by a sensitivity analysis of the design parameters. The results show that a large spacing in the direction of air flow contributes to improving system reliability. In this case, for the layout of a cross arrangement with equal spacing, the optimal reliability design scheme of a 5 x 5 parallel series with optimal design parameters can improve the cycle life from approximately 1989 to 2933 when taking 90% system reliability as the criterion. The collaborative optimization of redundancy and layout is of great importance to extend the service life and improve the system reliability of battery packs.

Automated summary

A novel reliability optimization method based on multiphysics coupling simulation and response surface methodology is proposed to optimize the redundancy and layout design of battery packs accurately and efficiently. By applying this method, the system reliability can be significantly improved through precise and efficient design optimization of battery pack redundancy and layout.