Value-added recycling of spent LiFePO4 by a FeCl3 leaching-spray pyrolysis approach

Traditional recycling technologies for spent lithium iron phosphate (LiFePO 4 , LFP) usually suffer from issues such as complex procedures, heavy chemical consumption, and limited economic viability. Herein, we propose a method combining FeCl 3 leaching and spray pyrolysis for the high-value-added recycling of spent LFP. Using FeCl 3 as leaching agent, over 99 % of Li is selectively leached out within 30 min with a solid-liquid ratio up to 300 g L −1 . The resulting leaching residue (FePO 4 ) serves as a precursor for the synthesis of new LFP. Subsequently, the Li and Fe-containing leachate undergoes a spray pyrolysis process, yielding a pyrolysis powder comprising LiCl and Fe 2 O 3 . Through a water-leaching procedure, the separation of LiCl and Fe 2 O 3 is achieved based on their distinct solubility in water. The resulting high-purity LiCl solution and Fe 2 O 3 residue are directly utilizable for producing battery-grade Li 2 CO 3 and LFP cathodes, respectively. LFP/C cathodes, synthesized using the recovered Li 2 CO 3 and FePO 4 precursor, exhibit an impressive 99.8 % capacity retention after 200 cycles at a 1C rate. This method holds great economic and environmental benefits by producing high-value-added products while avoiding the consumption of acids or alkalis.