Sustainable Lithium Recovery from 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.