A dual-pathway framework for upcycling spent cathodes beyond conventional recycling

Journal article, 2027

The rapid growth of the lithium-ion battery (LIBs) has created an urgent demand for sustainable recycling technologies. Although conventional pyrometallurgical and hydrometallurgical recycling efficiently recover critical metals, their reliance on complete material decomposition inevitably sacrifices the structural and functional value embedded in spent cathodes. This limitation has stimulated growing interest in value-retention strategies, among which direct regeneration and electrocatalytic repurposing have emerged as two promising yet fundamentally different approaches. This review summarizes recent advances in direct regeneration and electrocatalytic repurposing, highlighting their fundamentally different principles, feedstock requirements, and value-retention mechanisms. Direct regeneration restores electrochemical functionality through structural repair, whereas electrocatalytic repurposing converts spent cathodes into functional catalysts by exploiting their intrinsic elemental composition. Analysis of recent progress reveals that these approaches are complementary rather than competing, with fundamentally different requirements for feedstock quality, structural integrity, and compositional traceability. Based on these distinctions, an adaptive value-retention framework is proposed in which pathway selection is guided by cathode chemistry, degradation severity, and recycling scenario. Finally, emerging opportunities enabled by digital battery passports, advanced diagnostics, artificial intelligence, and standardized environmental and techno-economic assessment are highlighted as key enablers of intelligent recycling systems. By integrating these technologies within an adaptive decision-making framework, this Review provides a unified perspective for developing flexible, economically viable, and sustainable LIB recycling systems.