Sustainable and Facile Method for the Selective Recovery of Lithium from Cathode Scrap of Spent LiFePO4 Batteries

Lithium recovery from spent LiFePO 4 batteries is significant to prevent resource depletion and environmental pollution. In this study, the employment of “water in salt” electrolyte in LiFePO 4 battery enlightened us to develop a novel method for the selective recovery of lithium from spent LiFePO 4 batteries through oxidizing LiFePO 4 to FePO 4 with sodium persulfate (Na 2 S 2 O 8 ). Effect of several variables on the Li leaching efficiency was investigated. Additionally, combined thermodynamic analysis and characterization of XRD, XPS were employed to investigate the leaching mechanism. More than 99% of Li can be selectively leached in 20 min at ambient temperature with only 0.05 times excess of Na 2 S 2 O 8 . The high leaching efficiency can be ascribed to the stability and without destruction for the solid structure during the oxidation leaching. A closed-loop process was then proposed for recycling entire spent LiFePO 4 batteries, and finally high purity Li 2 CO 3 (99 wt %) was successfully prepared. The process is economically feasible and environmentally friendly and has great potential for the industrial-scale recycling of spent LiFePO 4 batteries.