Abstract:Driven by the "Dual Carbon" goals (carbon peaking and carbon neutrality), the recycling of spent lithium-ion batteries (LIBs), particularly those with ternary cathode materials (LiNixCoyMnzO2, NCM), has become a crucial step toward achieving resource circularity and emission reduction. Conventional recycling techniques, such as pyrometallurgical and hydrometallurgical processes, are often associated with high energy consumption, complex multi-step procedures, and the generation of low-value outputs, such as basic metal salts or compounds. These limitations present significant economic and environmental bottlenecks. Therefore, shifting the focus from simple "metal recovery" to high-value "material regeneration" is imperative. In recent years, promising high-value utilization routes that directly convert leaching solutions into cathode material precursors have advanced rapidly. However, research in this area remains relatively fragmented, lacking systematic consolidation and critical evaluation of the various approaches. This review begins by comprehensively examining technological progress in the pretreatment of spent ternary LIBs, metal leaching, and leachate purification. It then focuses on analyzing three primary high-value utilization pathways based on metal-rich leachates: co-precipitation, spray pyrolysis, and sol-gel methods. For each pathway, the working principles, technical advantages, and key challenges for industrialization are elucidated in detail. A comparative analysis is conducted from multiple perspectives, including adaptability to complex and variable battery waste streams, recovery efficiency (balancing metal yield and product purity), engineering scalability (addressing continuous production and equipment design), and the electrochemical performance of the regenerated cathode materials. Despite their considerable promise, these high-value pathways face several common challenges: sensitivity to fluctuations in feedstock composition, which affects process robustness; a persistent trade-off between energy/reagent consumption and economic viability; technical barriers to process scaling and continuous operation; and a performance ceiling, whereby regenerated materials often merely restore rather than exceed the properties of their virgin counterparts. To overcome these challenges and accelerate the industrialization of high-value LIB recycling, future research and development should converge on several integrated directions: (1) developing intelligent, adaptive processes capable of handling complex feedstocks through real-time monitoring and machine learning; (2) innovating low-carbon, short-process technologies and integrated reaction-separation systems to minimize energy and reagent use; (3) advancing equipment design and process engineering to enable efficient, stable large-scale production; and (4) exploring intrinsic performance-enhancing strategies during recycling, such as targeted doping or microstructure engineering, to elevate the functionality and value of regenerated cathode materials beyond conventional levels. This review aims to provide a structured reference and actionable insights to facilitate the industrial adoption of high-value recycling technologies for spent lithium-ion batteries. Close-