Emerging membrane technologies for sustainable lithium extraction from brines and leachates: innovations, challenges, and industrial scalability

• Main Authors: Foo, Zi Hao, Lienhard, John H.
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Article
• Language: English
• Published: 2024
• Subjects: Engineering; Critical materials; Direct lithium extraction; Brine concentration; Sustainable mining; Membranes
• Online Access: https://hdl.handle.net/10356/181795
• Institution: Nanyang Technological University

This perspective critically examines challenges in advancing membrane-based technologies for lithium extraction from industrial brines, salt lakes, and battery leachates. The rapidly rising deployment of electric vehicles and renewable energy systems has intensified global lithium demand, necessitating sustainable and efficient extraction methods. Traditional techniques like brine evaporation and hard rock mining are environmentally detrimental due to high water usage, ecological disruption, and significant carbon emissions, compounded by geopolitical risks from resource concentration. Emerging membrane technologies, utilizing lithium-selective ligands, biomimetic ion channels, and two-dimensional and porous materials, can potentially realize orders-ofmagnitude improvements in lithium selectivity for direct lithium extraction (DLE). However, the effectiveness of DLE membranes is constrained by impurity co-extraction, environmental hazards, lack of scalability and material instability. Conventional lithium brine concentration (LBC) techniques, which complement DLE by concentrating lithium for downstream applications like battery production, face challenges in hypersaline environments, such as fouling and reduced selectivity. Advances in electrodialysis and nanofiltration with surface modifications offer promising solutions to sustain favorable monovalent selectivity under high salinity conditions. Key gaps in the current research landscape include the absence of standardized testing procedures, evaluation metrics poorly suited to hypersaline or multi-ionic environments, scalability challenges in manufacturing, and economic limitations arising from fouling and material degradation. Addressing these issues requires material characterization with representative solution compositions, the development of comprehensive evaluation frameworks, and strategies for co-extracting valuable metals to improve economic viability. A holistic focus on membrane manufacturability, material durability, and process integration is essential to unlock sustainable lithium extraction technologies that can support the global shift to clean energy.