A Comparative Analysis of Cathode Stripping Methods for Direct Recycling of Spent Li-Ion Batteries

Abstract

Abstract The cathode is the most valuable battery component rich in precious metals and, thus, is the leading recycling target in spent lithium-ion batteries. In particular, the emerging development of direct recycling techniques requires the non-destructive spent cathode as feedstock; however, posing a challenge to effectively strip the spent cathode powders without destroying the cathode structure after disabling the binders. In this study, we compare four cathode stripping methods, including solvent dissolution & magnetic stirring, solvent dissolution & sonication, heat treatment & curling-uncurling, and solvent dissolution & resonant acoustic vibration. Our results show that solvent dissolution & resonant acoustic vibration-based cathode stripping achieves an efficiency of up to 92%, without introducing impurities such as small aluminum fragments and powders. These findings demonstrate the potential of resonant acoustic vibration-based cathode stripping for scaling up the cathode powder recovery and direct recycling of spent Li-ion batteries.