Sustainable high-efficiency photocatalytic lithium recovery from spent LiFePO₄ batteries: green process design and performance validation

Recycling spent lithium iron phosphate batteries is of great significance for both economic and environmental protection. Herein, a new strategy has been introduced: using MoS2, a green and recyclable photocatalyst, to efficiently extract Li from spent lithium iron phosphate batteries. The dissolution conditions for valuable metals were optimized by varying the ratio of MoS2 to spent lithium iron phosphate (sLFP), the ratio of water to MoS2, leaching time, temperature, and other parameters. The results indicated that under the optimized conditions, the leaching rate of Li exceeded 98%, while the leaching rates of Fe and P were below 20%, and the leaching P and Fe could be converted to FePO4 by air oxidation. Using Na2CO3 as a precipitant, more than 99% of Li could be recovered from the leaching solution in the form of Li2CO3. Besides, the results of repeated leaching and light irradiation experiments indicated that the photocatalyst MoS2 had excellent reusability. Furthermore, photocatalytic reactions under high Li+ concentration conditions demonstrated the feasibility of Li+ enrichment processes.