An effective lithium ion-imprinted membrane containing 12-crown ether-4 for selective recovery of lithium

The high lithium content in spent lithium ion batteries (LIBs) and a large number of spent LIBs generation shift the target of lithium recovery to solid waste. Adsorption separation is of great application value for lithium recovery. There is still a lack of a lithium adsorption material with excellent properties. Herein, an environmental hydrolytic polymerization to prepare lithium ion-imprinted membranes (LIIMs) with high adsorption capacity and selectivity is presented. The LIIMs can reach adsorption equilibrium in 40 min, showing fast adsorption kinetics. The optimal adsorption capacity of the LIIMs for Li+ was 132.00 mg g−1 after immersing in a 300 mg L−1 LiCl solution based on ample binding sites and a strong affinity force. Langmuir isothermal adsorption results proved that the imprinting sites on LIIMs were homogeneous. The selective separation factors (α) of Li+ to Mg2+, K+, Ca2+, Na+ were 6.80, 17.00, 21.30, and 24.60, respectively, which implies the superior selectivity LIIMs toward Li+. The adsorption capacity of LIIMs remained about 97 % after six cycles. Due to the suitable cavity, abundant rebinding sites, and strong affinity, the LIIMs have a good selective adsorption ability to Li+. Therefore, the LIIMs would have potential applications for separating Li+ from spent LIBs.