Green recycling of dominant LFPs for selective lithium recovery

The energy storage and electric vehicle markets are becoming more and more dominated by lithium iron phosphate (LFP) batteries, which calls for effective end-of-life recycling techniques. For sustainable resource recovery, selective lithium extraction from spent LFP black mass is essential to prevent needless, chemically demanding co-leaching of iron and phosphorus. This study examines the hydrometallurgical recovery of lithium utilizing a variety of organic acids that are safe for the environment, such as lactic, tartaric, maleic, and acetic acids. Acetic acid showed the best lithium extraction efficiency, up to 98 %, and selectivity among the lixiviants under investigation. Additionally, the assessment of hydrogen peroxide as a reductant showed that adding it did not considerably increase the lithium recovery, suggesting that an economical, reductant-free method is potentially feasible. The acetic acid leaching procedure was methodically improved to increase the recovery yield. To determine the optimal reaction conditions, the impacts of various operational parameters including leaching temperature, acid strength, solid to liquid ratio and leaching duration on lithium recovery were thoroughly assessed. Overall, this study offers a mild organic acid solution that is optimized, highly effective, and sustainable for the selective recovery of lithium from spent LFP batteries, vis-à-vis regeneration of lixiviant. The synthesised lithium product can be effectively used for new LFP making.