Concentrating and Rejecting Lithium Ion Using Forward and Reverse Electro-nanofiltration

Abstract

The increasing use of electric vehicles (EVs) and hybrid electric vehicles (HEVs) to reduce CO₂ emissions has raised the demand for lithium for lithium-ion batteries (LIB). LIBs are not solely confined to applications within EVs and HEVs. LIBs are crucial in capturing and storing energy generated from renewable sources, including solar and wind, highlighting their importance in advancing sustainable energy technologies. Therefore, effectively concentrating lithium (Li⁺) containing lithium-ion is crucial for recovering Li⁺ from brine or repurposing battery effluent to meet the demands for producing LIB. Electro-nanofiltration is one of the convincing methods because of its low energy consumption and cost compared to other filtration methods. In this paper, a low concentration of Li⁺ (78 ppm) and a high concentration of Na⁺ (2200 ppm) solution will be fed into the nanofiltration module. The nanofiltration membranes used are NF 1 and NF 2 from Membrane Technology (Beijing) Co., Ltd., with a forward electric field (EFs), reverse (EFs), and no electric field conditions. The experiment with 5 bar pressure findings shows that a high concentration of Na⁺ solution has a high rejection rate with NF 1 membrane without EF 40%, compared with a low concentration of Li⁺ solution with NF 1 10% rejection. The presence of EFs significantly influences rejection rates, with the NF 2 membrane in the Forward EF configuration Na+ solution having a -327% rejection rate, which is a dramatic decrease from the standard filtration of 40% rejection.