Cost-efficient closed-loop recovery and regeneration of LiFePO4 cathodes via a sodium persulfate-assisted route

A closed-loop route for spent LiFePO 4 recycling with 98.97% Li and 99.23% Fe recovery. • Sodium persulfate-assisted process enables efficient FePO 4 regeneration and separation. • Regenerated LiFePO 4 delivers 139.2 mAh g −1 at 1 C and 95.2% retention after 300 cycles at 5 C. • The process achieves 557.6 USD t −1 profit with lower cost and environmental impact. The sustainable recycling of spent LiFePO 4 (LFP) cathodes is hindered by the trade-off between efficient element separation and cost-effective closed-loop regeneration. Herein, we present an integrated approach combining the optimized acid leaching with sodium persulfate (Na 2 S 2 O 8 )-assisted oxidative precipitation, aiming to overcome this limitation. An orthogonal experimental design establishes the optimal leaching conditions (The spent LFP:H 3 PO 4 :H 2 SO 4 =1:0.62:0.57, 60 °C, liquid/solid ratio of 6:1), achieving high recovery efficiencies of 98.97% for Li and 99.23% for Fe. Remarkably, this strategically optimized integrated process reduces processing costs to only 60% of conventional pyrometallurgical routes and 88% of typical hydrometallurgical routes, while the regenerated LFP exhibits high crystallinity, uniform morphology, and a well-recovered olivine structure. When assembled in Li-ion batteries, R-LFP delivers a discharge capacity of 139.2 mAh g −1 at 1 C and retains 95.2% of its capacity after 300 cycles at 5 C, outperforming spent LFP and rivaling the best-reported regeneration methods. By simultaneously integrating high recovery efficiency, low processing cost, and outstanding electrochemical performance, this work provides a practical, sustainable, and industrially viable closed-loop recycling strategy for spent LFP cathodes that is well-suited for large-scale application. Download: Download high-res image (103KB) Download: Download full-size image