HOUSTON, TX – February 28, 2025 – Researchers at Rice University have unveiled a revolutionary lithium extraction technique that could significantly impact the electric vehicle (EV) industry by ensuring a more sustainable and efficient supply of this critical battery component. The team, led by Professor Menachem Elimelech, has demonstrated near-perfect lithium selectivity using solid-state electrolytes (SSEs) as membrane materials in aqueous solutions.
The study, published in Science Advances, details how SSEs, originally designed for solid-state batteries, effectively separate lithium ions from other ions and water in liquid mixtures. This innovation addresses a major challenge in lithium extraction: the difficulty of separating lithium from similar ions like magnesium and sodium, which are often found in sources such as oil and gas wastewater, industrial runoff, and geothermal brines.
“The challenge is not just about increasing lithium production but about doing so in a way that is both sustainable and economically viable,” stated Menachem Elimelech, the Nancy and Clint Carlson Professor of Civil and Environmental Engineering at Rice University.
The traditional lithium extraction methods, which often involve extensive mining and evaporation ponds, are environmentally damaging and time-consuming. The Rice University team’s new method leverages the unique properties of SSEs. Unlike conventional membranes that rely on hydrated pores, SSEs facilitate lithium ion transport through an anhydrous hopping mechanism within a crystalline lattice.
“This means that lithium ions can migrate through the membrane while other competing ions, and even water, are effectively blocked,” explained Sohum Patel, a postdoctoral researcher now at the Massachusetts Institute of Technology (MIT) and the study’s first author. “The extreme selectivity offered by our SSE-based approach makes it a highly efficient method for lithium harvesting as energy is only expended towards moving the desired lithium ions across the membrane.”
The researchers, including Arpita Iddya, Weiyi Pan, and Jianhao Qian, conducted experiments using an electrodialysis setup, applying an electric field to drive lithium ions across the SSE membrane. The results showed consistent near-perfect lithium selectivity, even in solutions with high concentrations of other ions.
Through computational and experimental analysis, the team discovered that the SSE’s rigid crystalline structure acts as a molecular sieve, allowing only lithium ions to pass while blocking water and larger ions. The difference in charge between lithium and magnesium ions also contributed to the high selectivity.
While competing ions did reduce lithium flux by occupying surface sites, the researchers believe this can be addressed through further material engineering. The potential applications of this technology extend beyond lithium extraction.
“The mechanisms of ion selectivity in SSEs could inspire the development of similar membranes for extracting other critical elements from water sources,” Elimelech said. “This could open the door to a new class of membrane materials for resource recovery.”
The development of SSE-based membranes could significantly streamline lithium extraction, reducing the environmental impact and ensuring a more stable supply for the rapidly growing EV and renewable energy sectors.
Keywords:
lithium extraction, solid-state electrolytes, electric vehicles, sustainable technology, resource recovery, Rice University, Menachem Elimelech, Sohum Patel, Science Advances, electrodialysis, battery supply chain.
