Electrochemical Direct Recycling and Upcycling of End-of-Life Lithium-Ion Batteries

초록

The increasing deployment of lithium-ion batteries (LIBs) has created an urgent demand for sustainable recycling technologies that can preserve material value while minimizing environmental impact. Conventional pyrometallurgical and hydrometallurgical recycling processes rely on energy-intensive operations and aggressive chemical treatments, which recover metals but destroy the intrinsic crystal structures of electrode materials. Here, we present a comprehensive direct recycling and upcycling framework for end-of-life LIBs based on electrochemical separation and material regeneration. Central to this strategy is an electrochemical delamination process that enables clean and selective separation of cathode active materials from aluminum current collectors without acid leaching or mechanical damage. An alternating electrochemical bias induces anodic oxidation and gas evolution at the Al interface, leading to interfacial weakening through Al2O3 formation and O2/H2 bubble generation. This process preserves the primary-particle morphology of the recovered NCM cathode powders. To further address nickel deficiency and incomplete lattice recovery in degraded cathodes, a nickel-catalyzed direct recycling route is introduced. Uniform nickel electroplating via cyclic voltammetry promotes oxygen incorporation, lithiation, and defect correction during thermal treatment, enabling complete lattice restoration and electrochemical performance comparable to commercial cathode materials. Beyond cathodes, spent graphite anodes and iron battery housings are upcycled through electrochemical processes to produce iron-oxide-decorated graphene-based composite anodes with high capacity and superior cost efficiency. Overall, this work demonstrates that direct recycling is not merely a separation strategy but a materials re-engineering platform, offering a viable pathway toward fully integrated closed-loop recycling of lithium-ion batteries.