Repurposing and Analysis of Used LiFePO4 Battery Cells Using Electrochemical Impedance Spectroscopy

Lithium-ion batteries (LIBs) have become integral to modern energy solutions, yet their widespread usage poses challenges in end-of-life management and recycling. This study addresses these challenges by analyzing and repurposing used Lithium-iron Phosphate (LiFePO4) battery cells from electric vehicles. Through Electrochemical Impedance Spectroscopy (EIS) and cycle aging tests, battery health and performance are evaluated. Additionally, a power bank application is developed using the evaluated cells. The experimental setup involves an electrochemical workstation, computer interface, and battery test system, enabling accurate measurements. Testing procedures include cycle aging tests and EIS analysis. Subsequently, a power bank is designed using the evaluated LiFePO4 cells, providing a portable energy solution. Results demonstrate impedance behavior, capacity fade, and discharge capacity trends, guiding decisions on repurposing or recycling battery cells. The power bank exhibits efficient charging capabilities and compatibility with modern devices, highlighting the viability of LiFePO4-based solutions. This study underscores the potential of LiFePO4-based power banks to offer reliable, efficient, and environmentally friendly charging solutions while extending the lifespan of used battery cells.