Hydrogen Bond Donor-Mediated Selectivity-to-Efficiency Trade-Off in Sustainable Recycling of Lithium-Ion Battery Cathodes

Sustainable recycling of lithium-ion battery (LIB) cathodes is essential for mitigating resource depletion and environmental pollution. However, the inherent trade-off between selectivity and efficiency remains a critical barrier limiting the performance of current recycling technologies. Herein, we demonstrate that the selectivity and efficiency of metal leaching from LiCoO2 cathodes in spent LIBs can be effectively mediated by the hydrogen bond donor (HBD) in sustainable low-melting mixture solvents. Employing phosphorous acid as the HBD in a betaine:phosphorous acid-based solvent system yields ultrahigh Li/Co selectivity during leaching from the LCO cathode. In contrast, high overall recovery efficiencies for both Li and Co are achieved when phosphoric acid serves as the HBD in a betaine:phosphoric acid-based solvent system.