From waste to catalyst: Recycling spent lithium-ion battery materials for water electrolysis and fuel cells

The retirement of lithium-ion batteries (LIBs) presents significant environmental challenges but also offers opportunities for resource recovery. Simultaneously, the high cost of precious metal catalysts hinders the widespread adoption of hydrogen technologies. This review provides a comprehensive overview of the innovative pathway of converting spent LIB materials into electrocatalysts for water electrolysis and fuel cells. We critically assess the current state-of-the-art in recovering cathode materials and anode graphite and their subsequent transformation into active catalysts for the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR). Key conversion strategies, including direct regeneration, hydrometallurgical re-synthesis, and pyrometallurgical recovery, are analyzed for their potential to engineer catalyst composition and morphology. The review highlights that recycled catalysts can achieve performance comparable to, and in some cases exceeding, that of commercial benchmarks. We also discuss the critical challenges for industrial scalability, such as feedstock heterogeneity and process integration, outlining future directions for establishing a circular economy that turns waste batteries into a key resource for sustainable energy. • Proposes an integrated waste battery materials-to-electrocatalyst roadmap. • Systematically summarizes and compares various recycling and regeneration technologies. • Reviews case studies of recycled battery materials as catalysts for water electrolysis and fuel cells. • Outlines future challenges in full-component synergistic recycling and engineering-scale application.