Sustainable Lithium Extraction For EV Batteries

Rice University Scientists Develop Near-Perfect Lithium Selectivity Membrane.

In the race to secure lithium for electric vehicle (EV) batteries, researchers at Rice University have unveiled a groundbreaking extraction method that could transform the industry. Their study, published in Science Advances, demonstrates an innovative use of solid-state electrolytes (SSEs) as membrane materials, achieving near-perfect lithium selectivity in aqueous solutions.

Initially designed for lithium-ion conduction in solid-state batteries, SSEs have been repurposed to enable an unprecedented level of ion separation. Unlike conventional membranes that use nanoscale pores for ion transport, SSEs operate through an anhydrous hopping mechanism within a rigid crystalline lattice. This structure effectively blocks competing ions like sodium and magnesium, allowing only lithium to pass through.

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“The challenge isn’t just increasing lithium production—it’s doing so in a sustainable and economically viable way,” said lead researcher Menachem Elimelech, a professor at Rice University.

Traditional lithium extraction methods, including mining and brine evaporation, are resource-intensive and environmentally harmful. Scientists have been exploring direct lithium extraction (DLE) from unconventional sources like industrial wastewater and geothermal brines to address these issues. However, existing DLE technologies struggle with ion selectivity, making lithium separation inefficient.

Elimelech’s team overcame this challenge using SSE-based membranes in an electrodialysis system, where an applied electric field drives lithium ions across the membrane. Even in solutions with high concentrations of competing ions, SSE membranes consistently achieved lithium purity levels that conventional technologies have failed to reach.

“The SSE lattice acts as a molecular sieve, excluding unwanted ions while allowing lithium to pass through,” explained Sohum Patel, the study’s first author and postdoctoral researcher at MIT.

As lithium demand surges in the EV, electronics, and renewable energy sectors, this breakthrough could provide a sustainable solution for lithium harvesting. By reducing reliance on mining and chemical-intensive purification, SSE-based extraction could secure a stable lithium supply with minimal environmental impact. Beyond lithium, researchers believe SSE membranes could inspire new technologies for extracting other critical elements, paving the way for more sustainable resource recovery.