State-of-the-art review on liberation of cathode material in pretreatment recycling of spent lithium-ion battery

Abstract

Pretreatment process is essential in lithium-ion battery (LIB) recycling. The pretreatment of spent LIB module pack typically includes disassembly, cell discharge, dissociation of electrode material using physical/chemical methods, and sorting of electrode material and current collector materials. Its main purpose is to separate the cathode material with the highest recycling value from other components of the battery, especially aluminum foil, enabling the following regeneration or efficient extraction of valuable metals by the hydrometallurgical process. Although some review articles have discussed the pretreatment methods of spent LIBs, to the best of our knowledge, few have specifically focused on the liberation of cathode material to date. Recently, significant progress has been made in this field, with advancements in physical fragmentation and grinding, organic solvent immersion, alkaline solution immersion, and heat treatment. Moreover, conventional heat treatment methods, especially pyrolysis, have seen notable improvements. Emerging technologies such as deep eutectic solvents (DES), high-voltage pulsed discharge, electrical separation, and acid-assisted separation have also garnered attention. Given the growing interest in LIBs recycling, the demand for comprehensive information on this topic is increasingly urgent. This state-of-the-art review aims to provide insights into the development of spent LIBs recycling technology.