Nanoconfined MXene/Cellulose Membranes for Selective Lithium Extraction from Brines and Black Mass
Kou Yang, Qinyue Wang, Konstantin G. Nikolaev, Qian Wang, Ivan V. Moskalenko, Shanqing Zhang, Xueqing Qiu, E.O. Timashev, Ekaterina V. Skorb, Kostya S. Novoselov, Daria V. Andreeva
Abstract
A nanoconfined thermoresponsive membrane composed of Ti 3 C 2 T x MXene and hydroxypropyl cellulose (HPC) was developed for selective Li + extraction. By integrating the electrothermal conductivity of MXenes and hydration-responsive gating of HPC, the membrane forms heterochannels with tunable spacing that regulate ion transport through nanoconfinement-enhanced mechanisms based on interaction energy and hydration radius. While density functional theory calculations predicted stronger sorption for Mg 2+, experimental data revealed a clear preference for Li + uptake from both simulated brine and battery black mass. This selectivity is attributed to favorable interactions of Li + within the nanoconfined composite channels, where the subnanometer interlayer spacings promote partial dehydration and size-sieving effects. Li + retention is governed not only by thermodynamic affinity but also by kinetic acceleration in nanoconfined pathways and hydration-based steric control. The membrane exhibits a reversible thermal response and maintains stable performance under Joule heating. It achieves >90% extraction efficiency from simulated Atacama brine and up to 98% Li + recovery from black mass supplied by VGM Sustainability Solutions (SG3R, Pte. Ltd.).