A Simulation Platform for Dynamic Equalization Analysis in Second-Life Lithium-Ion Batteries

The reuse of exhausted electric vehicle batteries in less demanding second-life applications is a promising solution to reduce waste and address concerns about environmental sustainability. Unfortunately, the cells used in second-life batteries show large capacity variability as a consequence of aging. This cell capacity mismatch strongly reduces the total battery capacity that is limited by the capacity of the least-performing cell. The dynamic equalization approach allows the battery system to maximize its usable capacity by transferring charges among the battery cells during the entire battery operation time. At the same time, the design of a dynamic equalization system requires particular care to obtain the best trade-off between performance and cost. A simulation platform is developed and presented in this paper to emulate a second-life battery storage system equipped with a dynamic equalization system. The platform aims to help the designer to compare the main active balancing architectures available and to identify their main design constraints. A second-life battery application case study is used to evaluate the simulation platform functionality. The obtained results highlight the capability of the platform to quantify the effects of the dynamic equalization system and its correct sizing.