Review on the recovery and reutilization of anode materials and electrolytes from spent lithium-ion batteries

Safe handling and utilization of graphite anodes and electrolyte materials in spent lithium-ion batteries (LIBs) are crucial for preventing serious environmental pollution. Therefore, a comprehensive review of the recent advances in recycling LIB anodes and electrolytes is presented to provide a better understanding of this topic. Among the existing electrolyte recovery processes and technologies, the supercritical CO₂ method is identified as the best in terms of recovery efficiency, quality, and environmental impact; however, its high cost limits its industrialization. In addition, methods for the separation, purification, regeneration, and utilization of the anode graphite are discussed to determine a reasonable route for graphite regeneration and reuse. Mechanical crushing and screening are suitable for industrial production; however, the separation of cathode and anode materials must be improved, and the subsequent removal sequence of binders and metal impurities from anode graphite must be optimized. Notably, rather than being burned during pyrometallurgy or discarded during hydrometallurgy, recovered anode graphite can be purified throughan appropriate method to permit its use as a carbon material in applications such as battery anodes, adsorbentsor graphene; however, the economics of using recycled carbon materials have not yet been fully evaluated. Finally, existing limitations and suggestions for LIB anode and electrolyte recycling processes are proposed to improve the separation, recovery, and reuse efficiencies of these materials. Thus, this review provides a theoretical basis and guidance for the regeneration and reutilization of anode and electrolyte materials to promote the feasible, efficient, economical, and environmentally friendly full recovery of spent LIB components.