Selective leaching of metal components from the spent LiFePO4 cathode material using (NH4)2S2O8

With the massive use of electric vehicles, spent electrode materials with no application value pose a serious threat to resource reserves and ecosystems. Consequently, recycling the spent electrode materials appears to be imminent. This study considered that lithium iron phosphate (LiFePO 4 ) within a water-stabilized voltage could undergo ionic leaching. Ammonium persulfate [(NH 4 ) 2 S 2 O 8 ], which has a high electrode potential, was used for selective leaching of the metal components from the spent LiFePO 4 material. The effects of leaching temperature, time, and the solid-liquid ratio on the leaching effect were investigated. Under optimized conditions, 99.2 % of Li in the spent LiFePO 4 could be leached effectively. The leaching reaction belonged to the typical chemical reaction control, and LiFePO 4 was converted to FePO 4 as Li + was continuously leached into the solution. The leaching of the spent LiFePO 4 using (NH 4 ) 2 S 2 O 8 did not require additional acids or bases to adjust the acidity of the solution, ensuring that the solution had a stable voltage. This strategy predicted that the selective leaching of metal components from the spent LiFePO 4 material could be enhanced using (NH 4 ) 2 S 2 O 8 , providing a certain basis for wet recovery in aqueous systems.