Engineering of Spinel Channels for Selective Lithium Recovery from Simulated End-of-Life Lithium-Ion Battery Leachate

Abstract Surging global demand for lithium-ion batteries (LIBs) creates an urgent imperative to recover critical materials from spent cells at scale. Here we integrate a spinel LiMn2O4 (LMO) ceramic membrane with a bipolar membrane electrodialysis (BMED) architecture enables self-sustaining ion-exchange. Water dissociation at the bipolar membrane generates a continuous proton flux that drives stoichiometric H+/Li+ exchange within the LMO lattice, providing in situ pH regulation without external eluent circulation. By decoupling lithium extraction from the discontinuous intercalation-deintercalation cycles inherent to conventional electrochemical approaches, this design enables continuous ion transport and faster extraction kinetics. Under optimized conditions, the system recovers a lithium recovery flux of 0.255 kg m–2 day–1 with a purity of 99.75%. This experimentally measured rate corresponds to a projected recovery of 254.5 g of Li+ over 24 h using a 1 m2 membrane. This work demonstrates continuous-flow, high-purity lithium recovery and expands ceramic ion-exchange membranes to other critical-mineral separations.