Lithium-ion batteries: Comprehensive technical analysis of second-life batteries for smart grid applications

In the upcoming years, thousands of battery storage systems will be decommissioned from electric vehicles. Instead of recycling or sending them immediately to landfills, these battery systems could be reused in other applications, such as grid or end-user applications. Second-life batteries are still expected to be capable of storing and delivering substantial energy. It is possible that they could satisfy the requirements of stationary applications. Indeed, the total lifetime value of the battery will increase when the remaining capacity of batteries can be invested to meet the requirements of other energy-storage applications. Consequently, the price of battery systems will be decreased, which helps the widespread commercialization both of electric vehicles and grid storage systems. However, there is an increasing need to investigate the potential of using second-life batteries in stationary applications (i.e., electric supply, ancillary services, grid system, end user/utility customer, and renewable integration). While some used battery technologies are now ready for commercial demonstration, there is no clear market structure to demonstrate the benefits of the used batteries for grid applications. While the need and opportunities for second-life batteries are obviously a number of gaps and limitations currently constrain the adoption of using the second-life batteries for grid-scale applications. Therefore, in this article, a comprehensive technical analysis is provided by addressing all aspects of a battery's life cycle to investigate the feasibility of reusing the retired EV batteries in stationary applications. This manuscript provides the experimental verification of the proposed solutions in order to face the main technical challenges, such as: lack of standards and models, aggravation of the aging process, difficulty testing and sorting staggering number of batteries, and inefficient of circuits and operational scenarios. Furthermore, Battery model is designed and verified by using MATLAB/Simulink environment.