Sustainable lithium recovery from a spent LiFePO4 cathode via K2S2O8-assisted solid state oxidation through mechanochemistry

Abstract

A rapid mechanochemical process using potassium persulfate (K₂S₂O₈) was developed for lithium extraction from spent LiFePO₄ cathodes. Nearly complete Li recovery (∼99.6%) was achieved within 30 min at 600 rpm, forming LiKSO₄ and FePO₄. Subsequent leaching and precipitation produced reusable Li₃PO₄, while the wastewater contained environmentally benign, fertilizer-grade K₂SO₄, indicating a sustainable recycling route.