Sustainable recycling of lithium-ion battery cathodes through facile electrochemical delamination

초록

In this study, we propose a straightforward method for reusing nickel-cobalt-manganese oxide (NCM) cathodes extracted from spent lithium-ion batteries. This method involves direct separation of the NCM film from the aluminum current collector, which is achieved through anodic oxidation of aluminum with the assistance of oxygen evolution. We thoroughly investigated the impact of the voltage type and delamination area on the delamination behavior of the spent cathodes. Furthermore, we assessed the reusability of the electrolyte employed for the electrochemical delamination of NCM, highlighting the potential scalability of this approach. Following the successful delamination of the NCM black film, we applied appropriate hydrothermal and sintering treatments to regenerate the NCM cathode capacity. After 100 cycles, the recycled NCM exhibited a reversible capacity of 143.6 mAh g- 1, retaining 84.7 % of its original capacity at 0.2C. This performance surpasses those of spent and pristine NCM, primarily owing to the successful regeneration of lithium loss and restoration of the layered structure. These aspects were analyzed using various characterization techniques, including X-ray diffraction (with Rietveld refinements), scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy , electrochemical characterization.

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