Optimized Thermal Treatment of Lithium-Ion Battery Components as a Basis for Sustainable Pyrometallurgy.

Abstract

The escalating global demand for lithium-ion batteries necessitates efficient and sustainable end-of-life management. Major recycling routes such as pyrometallurgy and hydrometallurgy offer promising paths for metal recovery, but their efficiency often depends on the pretreatment of spent batteries. However, optimizing low-temperature pretreatment for complete organic removal while preserving active material integrity remains challenging. This study investigated thermal decomposition and surface changes of key battery components-lithium nickel manganese cobalt oxide (NMC622) cathode, graphite anode, and polymeric separator-from 100 to 800 °C, focusing on the 400-650 °C industrial interval. Material responses were characterized using thermo-gravimetric analysis coupled with mass spectrometry, isothermal mass loss, and scanning electron microscopy with energy-dispersive X-ray spectroscopy. A 500 °C treatment was identified as optimal, enabling complete organic carbon removal within 1 h without compromising the NMC spinel structure or current collector degradation. This precise control reduces energy consumption and mitigates hazardous gas release, enhancing environmental sustainability and providing a practical, scalable, and cost-effective strategy for improving battery recycling. These findings help to define the parameters for efficient electroactive material separation. This work advances the understanding of low-temperature thermal pretreatment for battery recycling, supporting a circular economy for critical materials.