Advancing recycling of spent lithium-ion batteries: From green chemistry to circular economy

The critical supply of materials for lithium-ion batteries (LIBs) has become highly vulnerable to epidemics and geopolitical influences, highlighting the importance of independent and autonomous in situ recycling of LIBs. Many technologies have been developed rapidly for recycling spent LIBs in the last decade. However, their sustainability is seriously questioned, given the blind pursuit of recycling efficiency and profit maximization, even if the so-called innovative methods. Advanced recycling technologies should move forward in the direction of complying with the principles of green chemistry (PGC). This paper reviews global state-of-the-art recycling technologies developed for LIBs in recent decades within each of the principles of green chemistry. Furthermore, it critically assesses in reverse the extent to which each green chemistry principle has evolved. In particular, we have developed a unique indexing system for evaluating the performance of LIBs recycling technologies by integrating the PGC and the circular economy (CE) concept. Finally, future directions for improved research are highlighted. We hope to improve the greenness of technologies and guide the production and recycling processes of power LIBs.