Direct recovery of high-purity lithium via nanofiltration membranes from leaching solution of spent lithium batteries

The recycling of spent ternary lithium batteries (T-LIBs) promises scarce strategic resource recovery, however, efficient and selective recovery of Li+ from T-LIBs leaching solution with complex components is still a considerable challenge. Herein, we present a polyamide nanofiltration membrane based on the positively charged nanoscale dispersion interlayer for the first application in recycling lithium from the leaching solution of spent T-LIBs. The electronegativity is weakened by positive charge within the interlayer, which enhance the effect of Donnan exclusion. The pos-TFNi membrane can effectively permeate Li+ while the interfering divalent ions are almost completely separated, achieving the high purity (separation factor >= 93.5) and high recovery rate (79.2%) of Li+ from leaching solution simultaneously, with a 6.2-fold improvement in the separation factor over the pristine TFC membrane, and outperformed the majority of the NF membranes. This work represents a reference for the recycling of the massive accumulation of spent T-LIBs worldwide.