Feasible regeneration of cathode material from spent portable electronics batteries via nano-bubbles enhanced leaching

The rapid development of electric vehicles significantly aggravates the demand for ternary cathode materials. However, spent lithium-ion batteries (LIBs) from portable applications, generally composed of LiCoO2, dominate the volume for recycling. Besides, slow leaching kinetics and low leaching capacities are crucial factors that hinder the commercialization of hydrometallurgical recycling. Here, an economically feasible process for the regeneration of LiNi0.6Co0.2Mn0.2O2 (NCM622) from spent portable electronics batteries is proposed. By introducing oxygen nano-bubbles (O2 NBs) into the leaching solution, faster leaching kinetics and 2.5 times higher leaching capacities are obtained compared with those without O2 NBs. The regenerated NCM622 cathode material demonstrates a well-ordered layered hexagonal structure with a low degree of Li+/Ni2+ mixing ratio, which facilitates the reliable reversible capacity, low polarization, high rate capabilities, and capacity retention ratio. By adopting thermodynamic and the first-principles calculations, the mechanism for the regeneration process is revealed.