Building a Large-Scale Intrinsically-Safe Energy Storage System by Using Retired EV Batteries

Utilizing retired batteries in energy storage systems (ESSs) poses significant challenges due to their inconsistency and safety issues. The implementation of dynamic reconfigurable battery networks (DRBNs) is promising in maintaining the reliability and safety of battery energy storage systems (BESSs). Recently, large-scale BESSs based on DRBN have been deployed with the use of retired batteries, but the operational performance of these systems in real-world working conditions still remains uncertain. To bridge the research gaps, a case analysis is conducted based on the operational data from a real-world large-scale retired BESS. First, the framework of the retired BESS and the structure of the DRBN are illustrated in detail. Then, the core principle of DRBN is comprehensively demonstrated in terms of energy digitization and time-oriented battery management mode. Finally, the operational results indicate that the ESS can effectively improve the voltage and capacity consistency of battery modules and realize efficient thermal management to improve systematic safety of the retired BESS.