Recycling Spent LiFePO 4 Batteries for Fabricating LiI·3H 2 O and Li 2 CO 3 via Iodine Targeted and Mild Redox

ABSTRACT Selective lithium leaching from spent lithium iron phosphate (LFP) batteries is significant for promoting environmental and economic sustainability. However, it still faces issues such as low solid‐liquid ratio, high reagent consumption, high lithium loss and concomitant secondary waste. Herein, two short‐flow lithium recovery strategies based on iodine targeted redox are proposed for the sustainable recycling of spent LFP. Iodine achieves high lithium leaching efficiency of 93.48% at high solid‐liquid ratio (500 g L −1 ) under ambient condition and further enhanced to >99% via acid washing. The lithium leaching process is controlled by product layer diffusion. Distinguish from H 2 O 2 /S 2 O 8 2− induced lattice collapse and reconstruction, iodine triggers delithiation through mild oxidation of Fe(II), preserving FePO 4 with high crystallinity for direct regeneration. Strategy I proposes an innovative synthesis of lithium iodide trihydrate (LiI·3H 2 O) using spent LFP and iodine, without introducing external cations, achieving a considerable net profit of 23.66$ kg −1 . Strategy II establishes an I − /I 3 − redox‐mediated electrochemical regeneration system to circularly leach lithium from spent LFP for Li 2 CO 3 production, with low GHGs emissions and energy consumption. This work achieves high atom economy, providing an innovative paradigm for spent LFP batteries recycling with economic competitiveness and low‐carbon footprint.