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 materials recycled from spent LCO. Calcium chloride (CaCl2) was selected for chlorination, and roasting temperature, 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. [Display omitted] •Preferential lithium extraction from spent LCO and regeneration LCO were proposed.•Li was converted to LiCl for preferential extraction and Co was recovered as Co3O4.•The extraction rates of Li and Co were 99.49% and 98.12%, respectively.•Regenerated LCO exhibited excellent electrochemical performance.