Advances in the separation and purification of graphite anodes for spent Lithium-ion batteries

As power and energy storage batteries enter a phase of centralized retirement, the efficient recovery and recycling of graphite anodes have become a key link in achieving a closed-loop lithium battery industry chain. This review systematically examines the failure mechanisms, separation methods, purification technologies, and closed-loop management of graphite anodes, summarizing the typical technological routes and scalable process advancements in recent years. For the separation stage, the effective separation of graphite from black mass is achieved through crushing, screening, and multi-stage flotation. Meanwhile, dynamic cross-flow filtration (DCF) is used to concentrate the slurry and avoid excessive shear and dilution. For the purification stage, low-dose acid/base or complexing agents are employed to remove metal and fluorine residues, combined with medium-temperature thermal cleaning and short-duration high-temperature stabilization to restore graphite crystallinity. Furthermore, this review analyzes the key bottlenecks in the industrialization of graphite recycling and proposes a decision-making framework integrating key performance indicators and life-cycle assessment, providing direction for the resource recycling and green low-carbon recovery of graphite anodes.