Electrochemical Selective Lithium Extraction from Spent LiFePO4 Cathode Sheets and Regeneration via C/MgF2 Synergistic Coating Modification

Abstract

With the extensive application of LiFePO 4 (LFP) batteries in electric vehicles and energy storage systems, the issues of resource waste and environmental pollution caused by retired LFP batteries have become increasingly severe. However, traditional recycling faces the challenges of high energy consumption, high material consumption, and HF pollution. To address these, we propose a novel strategy that integrates electrochemical selective lithium extraction with a C/MgF 2 synergistic coating for regenerating spent LFP material. We achieved 98.73% lithium leaching (7V, 35°C, 0.04 mol/L, 60 min), 97.83% recovery via precipitation, 99.64% pure Li 2 CO 3 , and 98.13% Al foil recovery. MgO fixed PVDF-derived HF, forming MgF 2 to coat regenerated LFP. C/MgF 2 synergistic coating enhanced performance:151.3 mAh•g⁻ 1 at 0.1C (first discharge), 141.9 mAh•g⁻ 1 after 100 cycles 98.6% capacity retention at 1C, and 110.7 mAh•g⁻ 1 at 5C, matching commercial LFP. This method demonstrates a lowconsumption, environmentally benign route for upcycling spent batteries, transforming residual HF into C/MgF 2 coating for high-performance regenerated cathode materials.