Thermal approaches based on microwaves to recover lithium from spent lithium-ion batteries†

During the energy transition, the demand for strategic metals has become a focal point due to their crucial roles in advancing cleaner energy technologies and sustainable practices. As a response to the potential supply vulnerabilities of critical raw materials, recycling has gained attention, despite some methods being more expensive than traditional mining. In this context, new technologies based on microwave radiation have been recently introduced to recover lithium from spent lithium-ion batteries. This study highlights the innovative results achieved through the application of microwave heating to lithium cobalt oxide (LCO) black mass, showing that mass increase can support the possibility of proposing the technology as a new sustainable approach. The possibility of coupling carbon materials with magnetic materials, available in the black mass (BM) results in a strategic approach to increasing the final temperature of microwave-absorbing materials. The process proves highly efficient in lithium recovery, with a treatment at 600 W for 5 minutes, reaching a value higher than 80%, while also eliminating some labour-intensive pre-treatment steps. The research sheds light on both the advantages and potential challenges associated with this ground-breaking technology.