Lithium recovery from brines by lithium membrane flow capacitive deionization (Li-MFCDI) – A proof of concept

Dataset to H.M. Saif et al., Journal of Membrane Science Letters, Volume 3, Issue 2, November 2023, 100059

The demand of lithium for electric vehicles and energy storage devices is increasing rapidly, thus new sources of
lithium (such as seawater and natural or industrial brines), as well as sustainable methods for its recovery, will
need to be explored/developed soon. This work presents a novel electromembrane process, called Lithium
Membrane Flow Capacitive Deionization (Li-MFCDI), which was tested to recover lithium from a synthetic
geothermal brine containing a much higher mass concentration of sodium than lithium (more than 650 times).
Specifically, a ceramic lithium-selective membrane was integrated into a flow capacitive deionization (FCDI)
cell, which was specifically designed, and 3D printed, to allow simultaneous charging and regeneration of the
employed flow electrodes. Despite the extremely high Na+/Li+ mass ratio in the feed stream, 99.98% of the
sodium was rejected and the process selectivity for lithium over other monovalent cations was 141 ± 5.85 for
Li+/Na+ and 46 ± 1.46 for Li+/K+. The Li-MFCDI process exhibited a stable behaviour over a 7-day test period,
and the estimated energy consumption was 16.70 ± 1.63 kWh/kg of Li+ recovered in the draw solution. These
results demonstrate promising potential of the Li-MFCDI for the sustainable lithium recovery from saline streams.