Characterization and energy storage performance assessment of repurposed 18650 cylindrical lithium-ion cells for second life application in battery energy storage systems

The paper explores the viability of repuposing 18650 lithium-ion cells from consumer electronics at their end of life, collected from local electronics shops in Lagos Nigeria, for second-life application as Battery Energy Storage Systems (BESS). The study also characterizes each cell to determine its residual useful capacity and State of Health (SoH), physical quality, and performance before assembling them into modules and energy storage solutions for off-grid energy systems. The modules built have a capacity of 380 Ah and nominal voltage of 13.7 V, are modular and scalable to nominal voltages. The UL-1974 battery repurposing standards guides the methodology and experimental setup of the study. The cost per kilo watt hour (kWh) and environmental benefits of reusing these batteries are also explored and compared with alternatives. The results show that repurposing 18650 cells reduces waste and environmental impact while providing cost-effective energy storage alternatives to lead acid and first life lithium batteries.