Advanced Characterization and Rejuvenation of End‐Of‐Life Lithium‐Ion Anodes: Toward the Development of a Green Upcycling Route

The limited duty cycles of EV batteries necessitate robust end-of-life strategies to prevent landfilling and enable responsible resource management. Recycling remains the ultimate fate for battery waste, yet current hydrometallurgical practices rely on often lengthy and energy-intensive methods, which provide a major incentive for the development of cost-effective, shorter-loop regeneration routes to recycle end-of-life electrodes. This proof-of-concept study investigates the efficacy of deionized (DI) water and ascorbic acid (AA) in recovering entire spent anode systems from retired EV batteries without delamination and re-manufacture. Multi-modal characterization techniques were used to evaluate electrochemical, physicochemical, and morphological changes before and after treatment. High-resolution X-ray tomography and image-based simulations were used to quantify the microstructural metrics of pretreated and rejuvenated anodes. 3D visualizations of graphite and pore phases revealed insights into recycling mechanisms and rejuvenation effectiveness. Results demonstrate that DI water effectively removed surface impurities on graphite, significantly enhancing regeneration performance, with stable discharge capacities of ∼2.65 mAh/cm² over 20 cycles at 0.1 C, which exceeded both unused (2.36 mAh/cm²) and end-of-life (0.56 mAh/cm²) anodes. The study demonstrates that green chemistries can offer a sustainable alternative to hydrometallurgy and highlights the vital role of X-ray imaging in advancing circular battery technologies.