A green approach for cohesive recycling and regeneration of electrode active materials from spent lithium-ion batteries

Abstract

The implementation of the green energy transition by reducing reliance on fossil fuels has fueled the burgeoning demand for lithium-ion batteries in grid-level energy storage systems and electric vehicles. The growth of portable electronic devices has also contributed to this exponential demand, creating both logistical and environmental challenges in the supply of raw materials such as lithium and the management of end-of-life batteries. Current recycling methods for spent batteries are both energy-intensive and inefficient. To address these issues, a green approach using organic acid mixtures has been proposed to reclaim lithium from spent cathodes and recover and purify graphite from spent anodes, while also regenerating its structure. The effectiveness of this method is demonstrated through the use of organic acid mixtures to leach and reclaim lithium from NCM 622 batteries. On the anode side, a curing–leaching strategy using organic acids is employed to purify spent graphite, which is subsequently calcined to enhance its interlayer structure conducive to better intercalation of Li+ and improve electrochemical performance. Additionally, recovered graphite is tailored with carbon using water bath carbonization to repair structural defects caused by lithium intercalation and improve electrochemical performance while augmenting the regenerated graphite's quality, equipping it to be reused in batteries or upcycled applications.