Recycling and regeneration of anode graphite from spent lithium-ion batteries: Degradation mechanism, current strategies, and future prospects

The rapid expansion of the electric vehicle industry has significantly increased the demand for lithium-ion batteries, thereby underscoring the urgent need for sustainable recycling of end-of-life battery components. While the recovery of valuable cathode metals has been extensively studied, the recycling and regeneration of anode graphite remains underdeveloped and represents a critical bottleneck in achieving fully circular battery recycling. This review systematically examines the degradation mechanisms of graphite anodes, including structural degradation due to lithium (de)intercalation and the evolution of the solid electrolyte interphase. It further provides a comprehensive overview of emerging regeneration strategies, such as surface engineering, rapid thermal processing, and catalytic graphitization. These advanced approaches aim to efficiently remove impurities, restore structural integrity, and enhance electrochemical performance while reducing energy consumption and environmental impact. Despite the promising performance achieved at the laboratory scale, challenges associated with feedstock heterogeneity, purity control, and consistent structural restoration continue to hinder the large-scale integration of regenerated graphite into commercial battery manufacturing. Beyond regeneration mechanisms and electrochemical performance, this review further evaluates the technical maturity, environmental impacts, techno-economic feasibility, and regulatory drivers associated with graphite regeneration. Future efforts should focus on developing standardized regeneration protocols, advancing low-energy and scalable technologies, integrating life-cycle and techno-economic assessments, and strengthening the alignment between technological development and emerging regulatory requirements, thereby facilitating the industrial deployment of regenerated graphite within a circular battery economy.