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

TL;DR

This study shows a green method to rejuvenate old EV battery anodes using water and ascorbic acid, avoiding complex recycling processes and improving battery performance.

Contribution

A sustainable, solvent-based regeneration method for end-of-life lithium-ion anodes is proposed and validated.

Findings

DI water effectively removes surface impurities and enhances anode regeneration performance.

Rejuvenated anodes showed stable discharge capacities of ∼2.65 mAh/cm2 over 20 cycles, outperforming unused and end-of-life anodes.

X-ray imaging and simulations provided insights into microstructural changes and rejuvenation effectiveness.

Abstract

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.

Green solvents (DI water or ascorbic acid) enable the regeneration of end‐of‐vehicle‐life battery anodes without delamination and re‐manufacture. Multimodal characterizations reveal several graphite microstructures and crystallography, and restored cycling performance. We demonstrate a sustainable route for anode rejuvenation and circular battery materials recovery.

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