Stripping of cathode materials from aluminum foil using triethyl phosphate: Feasibility and mechanism analysis

The rapid expansion of electric vehicle (EV) industries has significantly increased global lithium-ion battery (LIB) production and consumption. Addressing resource scarcity and environmental concerns necessitates efficient battery recycling, where cathode material stripping from aluminum (Al) foil constitutes a critical preprocessing step. Although various techniques-including deep eutectic solvents, advanced oxidation processes, and molten salt systems-demonstrate stripping capability, their practical application is constrained by demanding operational conditions, excessive chemical costs, and procedural complexity. This study introduces an optimized organic solvent approach utilizing triethyl phosphate (TEP), which combines operational simplicity with cost-effectiveness. Experimental results demonstrate that thermal treatment at 80 °C with 100 rpm agitation for 20 min achieves consistent stripping efficiencies reaching 95.27 %. Remarkably, the process maintains > 89 % efficiency upon 10-time solvent recycling, confirming TEP's reusability. Mechanistic analysis reveals stripping is predominantly governed by thermal dissolution rather than chemical degradation. The developed protocol offers a practical solution for industrial-scale battery recycling, featuring mild processing conditions and reduced chemical consumption. This work not only establishes an efficient stripping methodology but also provides fundamental insights for sustainable pretreatment processes in LIB recycling.