Electrochemical Strategies for Closed-Loop Regeneration and Upcycling of Spent Batteries

The rapid growth of electric vehicles and portable electronic devices has substantially increased the demand for recycling end-of-life batteries. Although traditional pyrometallurgical and hydrometallurgical recycling technologies are industrially established, their broader application is constrained by high energy consumption, long processing times, and severe secondary pollution. Recently, electrochemical strategies have emerged as cleaner and more selective alternatives. By utilizing electrons as the primary reagent, these methods can provide controllable reaction selectivity and environmental compatibility under relatively mild conditions. This review summarizes recent advances in electrochemical strategies for the closed-loop regeneration and upcycling of spent batteries, covering electrochemical leaching, selective electrodeposition, direct cathode/anode regeneration, and functional upcycling. Particular attention is given to transforming degraded battery components into regenerated electrodes, electrocatalysts, water treatment, electromagnetic absorption materials, flexible biosensors, and next-generation energy storage materials. We further discuss key challenges and future directions such as mitigating manual risks through battery passports and AI-driven robots. This review aims to provide theoretical guidance and a forward-looking perspective for developing the next generation of low-carbon battery recycling technologies.