Sustainable and solvent-free delamination of spent LFP cathodes and their direct regeneration via stoichiometric hydrothermal re-lithiation

As the use of electric vehicles increases, sustainable end-of-life management of lithium iron phosphate (LFP) batteries becomes more crucial. However, because of their low intrinsic metal value and chemically stable olivine framework, traditional recycling methods such as pyrometallurgy and hydrometallurgy are often energy-intensive and economically disadvantageous for LFP cathodes. Here, we describe an environmentally safe direct regeneration method that employs hydrothermal re-lithiation following aqueous delamination of used LFP cathodes. The active material was successfully separated from aluminum current collectors using only water at room temperature, removing the need for harsh acids, hazardous solvents, or chemically rigorous separation procedures. Under comparatively mild conditions, effective lithium replenishment and olivine structure recovery were made possible by hydrothermal treatment. The regenerated LFP demonstrated exceptional long-term electrochemical performance, retaining 98.9% of its capacity over 500 cycles at 1C, displaying a discharge capacity of 146.32 mAh g −1 . For next-generation battery circularity, this study offers a scalable, low-impact recycling method that combines high-performance cathode regeneration with sustainable processing.