Aminobenzo-15-crown-grafted polyimide fibers for high-efficient and selective recovery of lithium from recycled Li-ion batteries

Global demand for lithium (Li) is experiencing a significant growth. A green and effective solution has been devised to address the increasing demand for resource recovery of Li from recycled Li-ion batteries. The objective of this study was to chemically graft 4′-Aminobenzo-15-crown-5-ether (AB15C5) onto polyimide (PI) fiber through a three-step method, resulting in the successful fabrication of AB15C5-functionalized PI fiber (PI-g-AB15C5). The PI-g-AB15C5 fiber exhibits a specific surface area of 2.69 m 2 g −1 as determined by Brunauer-Emmett-Teller analysis. The textiles derived from PI-g-AB15C5 are particularly significant. The textiles exhibit a higher specific surface area and elevated free pore volume, which enhance the full exposure of crown ethers and the adsorption of Li + . The PI-g-AB15C5 fiber exhibits advantageous hydrophilicity, has a significant equilibrium adsorption capacity for Li + (qmax = 21.09 mg g −1 ), demonstrates remarkable repeatability in cycling tests, displays excellent tensile properties, and maintains its fabric morphology during the adsorption process. PI-g-AB15C5 fiber effectively retrieved Li + in an acidic setting. When four interfering ions (Na + , K + , Co 2+ , and Mn 2+ ) were present, the PI-g-AB15C5 fiber demonstrated a remarkable ability to adsorb Li + selectively. The selective separation factors of Li + for Na + , K + , Co 2+ , and Mn 2+ were 8.47, 18.88, 6.99, and 9.85, respectively. A literature survey revealed that PI-g-AB15C5 fiber had better selective separation factors. The selectivity of PI-g-AB15C5 fiber towards Li + is supported by Density Functional Theory (DFT) calculations, which show that the greater Gibbs free energy change of the PI-g-AB15C5–Li + complex (−1008.82 kcal mol −1 ) is responsible for this exceptional selectivity. In summary, the functionality of this study’s polymer fiber material provides an effective method for recovering Li + from recycled Li-ion batteries. It can efficiently adsorb Li + , facilitating their selective separation from other heavy metals.