Self-actuated leaching and integrated separation of spent lithium-ion batteries cathode and anode sheets

The heavy metals in spent lithium-ion batteries (LIBs) are potential safety hazards to the environment. Conventional hydrometallurgical recovery techniques suffer from both economic and environmental challenges. Here, a novel two-step leaching and solvent extraction process are proposed to improve the leaching efficiencies and achieve the integrated leaching of LIBs cathode and anode sheets. The current collector (Al) enables the selfactuated enhanced leaching of the spent cathode sheet, the leaching efficiencies of Al3+, Li+, and Co2+ are 100 %, 71.29 %, and 63.53 %, respectively, under 0.4 M HCl and 40 min without external energy input. With di-(2ethylhexyl)phosphoric acid (D2EHPA), 98.99 % Al3+ can be selectively extracted from the leachate. The following electrochemical leaching of both spent cathode residual and spent anode sheet is carried out at low cell voltage, 99.8 % Li+, and 99.69 % Co2+ can be obtained in 90 min. Meanwhile, Al(OH)3, Co(OH)2, Li2CO3, and Cu are obtained from spent cathode and anode sheets with high crystallinity and purity, respectively. This strategy provides novel approaches for the integrated recycling of spent LIBs, thus realizing an environmentally friendly process with more application potential.