Characterization of Radiation-Grafted Ion-Adsorption Membranes for Battery Recycling

The increasing use of lithium-ion batteries in electric vehicles and energy storage systems has increased the need for eco-friendly technologies to recover valuable metals such as cobalt (Co) and nickel (Ni). In this study, ion-exchange membranes were fabricated by grafting sulfonic acid (-SO3H) and amine (-NH2, -N(CH3)2) groups onto polypropylene (PP) via radiation-induced polymerization. The sulfonated membrane (SS) showed high affinity for Co and Ni, with maximum adsorption capacities of 1.89 mg/g and 1.04 mg/g, respectively, whereas the amine-functionalized membrane (DEA-EtA) exhibited significantly lower capacities—0.004 mg/g and 0.05 mg/g—due to pH-dependent ionization. The membranes also maintained stable performance over repeated adsorption-desorption cycles, demonstrating good reusability. These findings indicated strong potential for selective metal recovery from spent batteries.