Selective recovery of lithium from spent LiFePO4 batteries based on PMS advanced oxidation process

The outstanding performance of LiFePO4 batteries has driven their widespread adoption in electric vehicles and energy storage systems. Consequently, there has been a significant increase in their disposal rate, making the proper handling of Spent LiFePO4 batteries a matter of paramount concern. While various methods for recovering cathode materials from spent LiFePO4 batteries have been extensively researched, the application of advanced oxidation processes for this purpose remains relatively underexplored. Advanced oxidation process (AOP) based on Peroxy-monosulfate (PMS, 2KHSO5-KHSO4-K2SO4) is a widely adopted AOP primarily based on sulfate radicals (SR-AOPs). In this paper, a PMS-based advanced oxidation process is proposed to recover lithium from LiFePO4 batteries. Li+ in LiFePO4 is released into solution by Fe2+ being oxidized, with a Li+ leaching rate of as high as 99.9 %, and the released Li+ is recovered in the form of Li2CO3 after reacting with Na2CO3, and at the same time FePO4 is generated, with its olivine structure remaining unchanged. The optimal experimental conditions were 1.15 times of the theoretical amount of PMS, 10 g/L solid-liquid ratio, 25 °C reaction temperature, and 20 min leaching time. This study provides a new recovery scheme for selective extraction of Li+ from spent LiFePO4 batteries, which is characterized by a simple recovery process and high efficiency.