Green Recovery of Cathode Active Materials from Li-Ion Battery Electrode Scraps Using Propylene Carbonate: A Novel Approach for Direct Recycling

Abstract

Retrieving cathode active materials from Li-ion battery electrode scraps is a crucial step in direct recycling; however, it presents challenges due to the strong bonds between the active material, carbon black, and binder. In this work, we propose the use of propylene carbonate (PC) as a green solvent for a solvent-based liberation/separation process. Compared to other green solvents, PC offers the advantage of efficiently liberating active materials from electrode scraps at a relatively low temperature and within a short time. The reclaimed cathode obtained through the PC-based process retains its morphological, structural, and electrochemical characteristics, demonstrating the suitability of the developed process for direct recycling. Additionally, the process provides an intriguing benefit by enhancing the charge-transfer resistance of the reclaimed active material. The use of PC in the solvent liberation/separation process offers a viable approach to mitigate impurity-related challenges commonly encountered in solvent-based processes. By leveraging the plasticizer effect of PC, the residual polyvinylidene fluoride species on the active material are transformed into species that facilitate Li-ion conduction. This transformation leads to an improvement in the overall electrochemical performance of the recovered cathode material.