Preferential extraction of lithium from spent LiCoO2 cathodes and regeneration of LiCoO2 cathodes

As the global consumption of lithium-ion batteries increased dramatically, recycling spent lithium-ion batteries became an urgent task, which is vital to alleviate resource shortages and maintain sustainable development. In this study, a strategy for preferential extraction of lithium from spent LiCoO2 (LCO) cathodes by chlorination roasting combined with water leaching was proposed, along with the regeneration of LCO cathodes with ma-terials recycled from spent LCO. Calcium chloride (CaCl2) was selected for chlorination, and roasting tempera-ture, dosage of CaCl2, and roasting time were optimized systematically. In this process, lithium was converted into water-soluble LiCl under a low chlorination atmosphere, the relatively stable Co-O octahedral structure was maintained in the solid phase, and preferential extraction of lithium was completed by subsequent water -leaching. The experimental results showed that 99.49% of Li was selectively recovered as LiCl which was further recovered as battery-grade Li2CO3, and 98.12% of Co was recovered in the form of Co3O4. Regenerated LCO cathodes (r-LCO) from recovered Li2CO3 and Co3O4, exhibited excellent electrochemical performance with a capacity of 141.2 mAh g-1 at 1 C and a high-capacity retention of 91.8% after 100 cycles.