Development of a discharge-free pre-treatment device for spent lithium-ion batteries under an inert atmosphere

Abstract

This study designs, fabricates, and experimentally validates an inert-atmosphere, discharge-free pre-treatment device for spent lithium-ion batteries (LIBs). The system integrates a vacuum pass-box with a processing enclosure (shredder and drying furnace) and enables continuous comminution and thermal drying while maintaining an internal oxygen concentration of ≤ 3% under argon. Trials on cylindrical 18650 cells involved vacuum loading, shredding, and a 300 °C, 2 h thermal step. Mass balance indicated an electrolyte-removal fraction of 5.3%, and the recovered black powder exhibited preserved NCM-type cathode signatures together with Cu/Al from current collectors, as confirmed by XRD, XRF, and SEM-EDS. Potentially harmful HF/HCl off-gases were neutralized in a NaOH scrubber prior to discharge. Compared with conventional brine-discharge → shredding → drying workflows, the proposed device mitigates wastewater and odor, suppresses ignition risk through atmosphere control, and is amenable to continuous, automation-ready operation, providing a practical alternative for industrial LIB recycling lines.