Interfacial polymerization enhanced UiO-66-NH2(PSS) membrane for selective separation of lithium/cobalt ions

In the advent of the new energy era, the global demand for lithium is increasing rapidly. The recovery of Li + and Co 2+ from the leachate of high-quality spent lithium-ion batteries (LIBs) offers significant economic and environmental benefits. This study proposes a TFC-ON-MOF membrane prepared through a combination of in situ growth and interfacial polymerization (IP) for the recovery of Co 2+ and Li + from battery leachate. Operated in an electrodialysis (ED) system, the experimental results demonstrated that the optimum Li + membrane flux was observed to reach 1.02 μmol cm −2 min −1 at 7.5 mA cm −2 , with the selectivity remaining at 19.84, which exemplifies well-separation and permeation performance. Following several operational cycles, the separation performance remained stable, and the membrane exhibited enhanced fouling resistance relative to commercial monovalent selective cation exchange membranes (CSO). The composite membrane features sub-nanometer windows and nanometer-sized cavities, enabling selective permeation of Li + while simultaneously sequestering Co 2+ . The inclusion of auxiliary permeation groups (PSS) also enhances overall permeation performance and selectivity. The findings contribute to the design of composite metal–organic frameworks and provide a novel approach for the selective separation of heavy metal ions from spent lithium batteries, thereby promoting the efficient recycling of valuable metal resources.